The Danish health care system and epidemiological research: from health care contacts to database records

Association between patient activation level and functional outcomes in older adults with hip fractures

BACKGROUND

Hip fractures can significantly impact older adults' mobility and function. Effective rehabilitation is crucial to help them regain independence and quality of life. However, little is known about the association between patient activation and hip fracture rehabilitation. This study aims to assess the association between the PAM-13 scores and the level of physical function, mobility, and activities of daily living in older adults following a hip fracture rehabilitation program.

METHOD

An exploratory outcome study from a cluster-randomized stepped-wedge clinical controlled trial. Two hundred thirty-nine patients were classified into four Patient Activation Measure-Levels (PAM-13) according to their PAM-13 scores, reflecting their confidence and preparedness to manage their health. Level 1 represents the lowest level of confidence. The patient's mobility, function, and daily activities were evaluated at discharge and after 12 and 24 weeks.

RESULTS

The cohort had a median age of 78; 67% were female, and 50% lived alone. There were no significant differences in demographics between the PAM-Levels. PAM-Level 1 patients had longer hospital stays and lower mobility scores than PAM-Level 4 patients. However, all patients improved over time, and higher initial PAM levels resulted in better outcomes. PAM-Level 1 patients improved in Time Up and Go score from a median score of 54 seconds to 14 seconds at 24 weeks, while PAM-Level 4 patients improved from 26 to 9 seconds.

CONCLUSION

Our study found an association between PAM levels and functional outcomes in hip fracture rehabilitation. Patients with higher activation levels had better mobility and functional outcomes.

Prognosis and antithrombotic practice patterns in patients with recurrent and transient atrial fibrillation following acute coronary syndrome: A nationwide study

BACKGROUND

First-time detected atrial fibrillation (AF) is associated with aggravated prognosis in patients admitted with acute coronary syndrome (ACS). Yet, among patients surviving beyond one year after ACS, it remains unclear how the recurrence of AF within the initial year after ACS affects the risk of stroke.

METHODS

With Danish nationwide data from 2000 to 2021, we identified all patients with first-time ACS who were alive one year after discharge (index date). Patients were categorized into: i) no AF; ii) first-time detected AF during ACS admission without a recurrent hospital contact with AF (transient AF); and iii) first-time detected AF during ACS admission with a subsequent recurrent hospital contact with AF (recurrent AF). From index date, two-year rates of ischemic stroke were compared using multivariable adjusted Cox regression analysis. Treatment with antithrombotic therapy was assessed as filled prescriptions between 12 and 15 months following ACS discharge.

RESULTS

We included 139,137 patients surviving one year post ACS discharge: 132,944 (95.6%) without AF, 3920 (2.8%) with transient AF, and 2273 (1.6%) with recurrent AF. Compared to those without AF, the adjusted two-year hazard ratios of ischemic stroke were 1.45 (95% CI, 1.22-1.71) for patients with transient AF and 1.47 (95% CI: 1.17-1.85) for patients with recurrent AF. Prescription rates of oral anticoagulation increased over calendar time, reaching 68.3% and 78.7% for transient and recurrent AF, respectively, from 2019 to 2021.

CONCLUSION

In patients surviving one year after ACS with first-time detected AF, recurrent and transient AF were associated with a similarly increased long-term rate of ischemic stroke.

Lipid Levels and Risk of Diabetic Polyneuropathy in 2 Danish Type 2 Diabetes Cohorts

BACKGROUND AND OBJECTIVES

Reduction of blood lipids may aid in preventing diabetic polyneuropathy (DPN), but evidence remains conflicting. We investigated the association between lipid parameters and DPN risk in individuals with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a population-based cohort study of individuals with newly diagnosed T2DM and a cross-sectional study using a clinically recruited T2DM cohort. Triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and non-HDL cholesterol were measured in routine diabetes care. Each lipid parameter was categorized according to the latest cutoffs in clinical guidelines on dyslipidemia. DPN was assessed with validated hospital diagnosis codes in the population-based cohort and with the Michigan Neuropathy Screening Instrument questionnaire in the clinical cohort. We calculated hazard ratios (HRs) using Cox regression and prevalence ratios (PRs) using Poisson regression.

RESULTS

We included 61,853 individuals in the population-based cohort (median age 63 [quartiles 54-72] years) and 4,823 in the clinical cohort (median age 65 [quartiles 57-72] years). The incidence rate of hospital-diagnosed DPN in the population-based cohort was 3.6 per 1000 person-years during a median follow-up of 7.3 years. Achieving guideline targets for HDL, LDL, and non-HDL cholesterol showed no association with DPN risk. By contrast, adjusted HRs (95% CI) for DPN were 1.02 (0.89-1.18) for triglyceride levels between 150 and 204 mg/dL (1.7-2.3 mmol/L) and 1.28 (1.13-1.45) for levels >204 mg/dL (2.3 mmol/L). In the clinical cohort with a DPN prevalence of 18%, DPN associated strongly with triglycerides >204 mg/dL (2.3 mmol/L) with an adjusted PR (95% CI) of 1.40 (1.21-1.62). The prevalence of DPN was modestly elevated for individuals with HDL cholesterol <39 mg/dL (1.0/1.3 mmol/L) in men and <50 mg/dL (1.3 mmol/L) in women (PR 1.13 [0.99-1.28]) and for individuals with non-HDL cholesterol >131 mg/dL (3.4 mmol/L) (PR 1.27 [1.05-1.52]). In both cohorts, spline models showed an increasing risk of DPN starting from triglyceride levels >124 mg/dL (1.4 mmol/L). All results were similar among statin users.

DISCUSSION

High triglyceride levels are a strong DPN risk factor. Future intervention studies shall determine whether triglyceride reduction is more important for DPN prevention than reduction of other lipids.

Impact of diabetes on the risk of subsequent fractures in 92,600 patients with an incident hip fracture: A Danish nationwide cohort study 2004-2018

PURPOSE

We investigated the incidence rates of a subsequent hip fracture (HF) and other subsequent fractures than HF after first incident HF, comparing patients with and without diabetes.

METHODS

Using Danish medical databases, we identified 92,600 incident HF patients in the period 2004-2018. Diabetes exposure was examined overall, by type of diabetes (T2D and T1D), and by presence of diabetes complications. We estimated cumulative incidence of subsequent HFs and fractures other than HF within two years of the incident HF. Using Cox regression, adjusted hazard ratios (aHRs) with 95 % confidence interval (CI) were calculated.

RESULTS

Among incident HF patients, 11,469 (12 %) had diabetes, of whom 10,253 (89 %) had T2D and 1216 (11 %) had T1D. The 2-year incidence rates for a new subsequent HF were 4.8 % (95 % CI: 4.6-4.9) for patients without diabetes (reference group), 4.1 % (95 % CI: 3.8-4.6) for T2D, and 4.3 % (95 % CI: 3.3-5.6) for T1D. Corresponding aHRs were 1.01 (95 % CI 0.90-1.14) for T2D and 1.17 (95 % CI 0.87-1.58) for T1D. There was effect modification by sex, as women with T1D had an aHR of 1.52 (95 % CI: 1.09-2.11) for subsequent HF, and by specific diabetes complications (for example, patients with T2D and prior hypoglycemia had an aHR of 1.75 (95 % CI: 1.24-2.42) for subsequent HF, while patients with T1D and neuropathy had an aHR of 1.73 (95 %: 1.09-2.75), when compared with patients without diabetes). For fractures other than HF, the 2-year incidence rates were 7.3 % (95 % CI: 7.2-7.5) for patients without diabetes, 6.6 % (95 % CI: 6.1-7.1) for T2D, and 8.5 % (95 % CI: 7.0-10.1) for T1D, with corresponding aHRs of 1.01 (95 % CI 0.92-1.11) for T2D and 1.43 (95 % CI: 1.16-1.78) for T1D. T2D was only a risk factor for other subsequent fractures among HF patients of high age (age 86-89 years: aHR 1.22 (95 % CI 0.99-1.55), age 90+ years: aHR 1.37 (95 % CI 1.08-1.74)), whereas T1D was robustly associated with increased risk of fractures other than HF in all subgroups.

CONCLUSION

Among HF patients, we found no strong overall association of T2D or T1D with increased risk of subsequent HF, but diabetes patients with prior hypoglycemic events or neuropathy were at increased risk. In contrast, patients with T1D had a clearly increased risk of subsequent fractures other than HF.

Use of Latent Class Analysis to Predict Intensive Care Unit Admission and Mortality in Children with a Major Congenital Anomaly

OBJECTIVE

To define major congenital anomaly (CA) subgroups and assess outcome variability based on defined subgroups.

STUDY DESIGN

This population-based cohort study used registries in Denmark for children born with a major CA between January 1997 and December 2016, with follow-up until December 2018. We performed a latent class analysis (LCA) using child and family clinical and sociodemographic characteristics present at birth, incorporating additional variables occurring until age of 24 months. Cox proportional hazards regression models estimated hazard ratios (HRs) of pediatric mortality and intensive care unit (ICU) admissions for identified LCA classes.

RESULTS

The study included 27 192 children born with a major CA. Twelve variables led to a 4-class solution (entropy = 0.74): (1) children born with higher income and fewer comorbidities (55.4%), (2) children born to young mothers with lower income (24.8%), (3) children born prematurely (10.0%), and (4) children with multiorgan involvement and developmental disability (9.8%). Compared with those in Class 1, mortality and ICU admissions were highest in Class 4 (HR = 8.9, 95% CI = 6.4-12.6 and HR = 4.1, 95% CI = 3.6-4.7, respectively). More modest increases were observed among the other classes for mortality and ICU admissions (Class 2: HR = 1.7, 95% CI = 1.1-2.5 and HR = 1.3, 95% CI = 1.1-1.4, respectively; Class 3: HR = 2.5, 95% CI = 1.5-4.2 and HR = 1.5, 95% CI = 1.3-1.9, respectively).

CONCLUSIONS

Children with a major CA can be categorized into meaningful subgroups with good discriminative ability. These groupings may be useful for risk-stratification in outcome studies.

Risk of heart failure among individuals tested for Borrelia burgdorferi sensu lato antibodies, and serum Borrelia burgdorferi sensu lato seropositive individuals; a nationwide population-based, registry-based matched cohort study

BACKGROUND

Lyme borreliosis is a tick-borne disease caused by the bacterium Borrelia burgdorferi (Bb) sensu lato complex. Previous studies have suggested an association between Lyme borreliosis and heart failure, which have been suggested to be a possible manifestation of Lyme carditis. We aimed to investigate the risk of heart failure among individuals tested for serum Bb antibodies, and serum Bb seropositive individuals.

METHODS

We performed a matched nationwide cohort study (Denmark, 1993-2020) and included 52,200 Bb seropositive individuals, and two age- and sex-matched comparison cohorts: 1) 104,400 Bb seronegative comparison cohort members, and 2) 261,000 population controls. We investigated the risk associated with 1) being tested for serum Bb antibodies, and 2) being Bb seropositive. Outcomes were: 1) a composite of heart failure, cardiomyopathy, and/or myocarditis diagnosis, and 2) redemption of cardiovascular medicine used for treatment of heart failure. We calculated short-term odds ratios (aOR) (within 1 month) and long-term hazard rates (aHR) (after 1 month) adjusted for age, sex, diabetes, pre-existing heart failure, and kidney disease.

RESULTS

Compared with the population controls, individuals tested for Bb antibodies, regardless of the test result, had increased short-term risk of heart failure, cardiomyopathy, and myocarditis (aOR 8.3, 95 %CI: 6.7-10.2), and both increased short- and long-term risk of redemption of cardiovascular medicine (aOR 4.3, 95 %CI: 3.8-4.8, aHR 1.13, 95 % CI: 1.11-1.15). The Bb seropositive individuals had no increased short- or long-term risk of any outcome compared with Bb seronegative comparison cohort members.

CONCLUSIONS

In conclusion, Bb antibody tests seemed to be performed in the diagnostic work-up of heart failure, but Bb seropositivity was not associated with heart failure.

Association of Antithrombotic Drug Use With Incident Intracerebral Hemorrhage Location

BACKGROUND AND OBJECTIVES

Few population-based studies have assessed associations between the use of antithrombotic (platelet antiaggregant or anticoagulant) drugs and location-specific risks of spontaneous intracerebral hemorrhage (s-ICH). In this study, we estimated associations between antithrombotic drug use and the risk of lobar vs nonlobar incident s-ICH.

METHODS

Using Danish nationwide registries, we identified cases in the Southern Denmark Region of first-ever s-ICH in patients aged 50 years or older between 2009 and 2018. Each verified case was classified as lobar or nonlobar s-ICH and matched to controls in the general population by age, sex, and calendar year. Prior antithrombotic use was ascertained from a nationwide prescription registry. We calculated odds ratios (aORs) for associations between the use of clopidogrel, aspirin, direct oral anticoagulants (DOACs) or vitamin K antagonists (VKA), and lobar and nonlobar ICH in conditional logistic regression analyses that were adjusted for potential confounders.

RESULTS

A total of 1,040 cases of lobar (47.9% men, mean age [SD] 75.2 [10.7] years) and 1,263 cases of nonlobar s-ICH (54.2% men, mean age 73.6 [11.4] years) were matched to 41,651 and 50,574 controls, respectively. A stronger association with lobar s-ICH was found for clopidogrel (cases: 7.6%, controls: 3.5%; aOR 3.46 [95% CI 2.45-4.89]) vs aspirin (cases: 22.9%, controls: 20.4%; aOR 2.14 [1.74-2.63; p = 0.019). Corresponding estimates for nonlobar s-ICH were not different between clopidogrel (cases: 5.4%, controls: 3.4%; aOR 2.44 [1.71-3.49]) and aspirin (cases: 20.7%, controls: 19.2%; aOR 1.77 [1.47-2.15]; p = 0.12). VKA use was associated with higher odds of both lobar (cases: 14.3%, controls: 6.1%; aOR 3.66 [2.78-4.80]) and nonlobar (cases: 15.4%, controls: 5.5%; aOR 4.62 [3.67-5.82]) s-ICH. The association of DOAC use with lobar s-ICH (cases: 3.5%, controls: 2.7%; aOR 1.66 [1.02-2.70]) was weaker than that of VKA use (p = 0.006). Corresponding estimates for nonlobar s-ICH were not different between DOACs (cases: 5.1%, controls: 2.4%; aOR 3.44 [2.33-5.08]) and VKAs (p = 0.20).

DISCUSSION

Antithrombotics were associated with higher risks of s-ICH, but the strength of the associations varied by s-ICH location and drug, which may reflect differences in the cerebral microangiopathies associated with lobar vs nonlobar hemorrhages and the mechanisms of drug action.

Risk of mortality and recurrence after first-time stroke among patients with type 2 diabetes: A Danish nationwide cohort study

INTRODUCTION

The prognosis for stroke patients with type 2 diabetes mellitus (T2DM) remains poorly understood. We examined the risk of mortality and stroke recurrence in stroke patients with T2DM and stroke patients without diabetes.

PATIENTS AND METHODS

We conducted a population-based cohort study including all patients diagnosed with a first-time ischemic stroke (n = 131,594) or intracerebral hemorrhage (ICH, n = 15,492) in Denmark, 2005-2021. Patients with T2DM were identified using hospital diagnosis codes and glucose-lowering drug prescriptions. We calculated risks, risk differences, and risk ratios, standardized by age, sex, and calendar year of stroke admission.

RESULTS

Following ischemic stroke, the 5-year standardized mortality was 46.1% for patients with T2DM and 35.4% for patients without diabetes (standardized risk difference: 10.7% [95% CI 9.9-11.6]; risk ratio: 1.3 [95% CI 1.3-1.3]). The 5-year risk of recurrence following ischemic stroke was 12.7% for patients with T2DM and 11.3% for those without diabetes (risk difference: 1.4% [95% CI 0.9-2.0]; risk ratio: 1.1 [95% CI 1.1-1.2]). Following ICH, the 5-year mortality was 62.8% for patients with T2DM and 53.0% for patients without diabetes (risk difference: 9.8% [95% CI 7.2-12.4)]; risk ratio: 1.2 [95% CI 1.1-1.2]). The 5-year risk of recurrence after ICH was 9.1% for patients with T2DM and 9.7% for patients without diabetes.

DISCUSSION AND CONCLUSION

Stroke patients with T2DM were at increased risk of mortality. The risk of stroke recurrence was slightly higher for ischemic stroke patients with T2DM than patients without diabetes, while no difference was observed among ICH patients.

Are cardiac rehabilitation pathways influenced by diabetes: A cohort study

BACKGROUND

Cardiac rehabilitation (CR) is recommended following acute coronary syndrome (ACS). Diabetes is a common long-term condition associated with ACS, and the inclusion of these patients in CR has been less studied. This study examines the referral, uptake, and completion rates in the CR pathway for ACS patients with and without diabetes to identify potential barriers in the CR pathway.

METHODS

The study included patients aged 18 or above who were discharged after a diagnosis of ACS in the Central Denmark Region between 1 September 2017 and 31 August 2018. Diabetes information was obtained from three sources. Logistic regression models were used to examine the associations between having diabetes and the three outcomes: non-referral, non-uptake and non-completion. Results were reported as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

A total of 2447 patients were eligible for the study, of which 457 (18.7%) had diabetes. Only non-uptake was found to be significantly associated with diabetes after adjustment for prespecified variables (OR = 1.38, 95% CI 1.01-1.90). Associations for non-referral (OR = 1.11, 95% CI 0.87-1.41) and non-completion (OR = 1.06, 95 %CI 0.73-1.53) were not found to be statistically significant in between ACS patients with diabetes and those without diabetes.

CONCLUSION

This study highlights a significant disparity in the uptake of CR between patients with and without diabetes following ACS, demonstrating that patients with diabetes require early promotion and increased assistance to enrol in CR.

Overall and cause-specific mortality in anorexia nervosa; impact of psychiatric comorbidity and sex in a 40-year follow-up study

OBJECTIVE

This study investigates the overall and cause-specific mortality in males and females with anorexia nervosa (AN) from 1977 to 2018, focusing on the impact of psychiatric comorbidity on mortality risk, a less explored aspect despite a high prevalence in patients with AN.

METHOD

We conducted a nationwide population-based cohort study in Denmark including all patients with AN (n = 14,774) with a median follow-up time of 9.1 years and a 1:10 age- and sex-matched general population comparison cohort. Using Cox proportional hazard model, we calculated adjusted hazard ratios (aHR) for death stratified by psychiatric comorbidity, sex, and age at AN onset and evaluated the causes of death using Fine and Gray sub-distribution hazard ratios (SHR).

RESULTS

In patients with AN, the weighted average aHR for all-cause mortality was 4.5 [95% CI 4.1-4.9] with up to 40 years follow-up. Psychiatric comorbidity was present in 47% of patients with AN at index date, which was associated with a 1.9-fold increase in 10-year mortality compared with patients without comorbidity and a notably four-fold increase, when diagnosed at age 6-25 years. The mortality risk was similar according to sex. 13.9% of all deaths in patients with AN were due to suicide (SHR 10.7 [8.1-14.2]). The risk of dying of natural causes was increased with a SHR of 3.8 [95% CI 3.4-4.2].

DISCUSSION

The increased mortality risk in both males and females with AN and psychiatric comorbidity, particularly when diagnosed at young age, underscores the need for comprehensive treatment addressing both AN and coexisting psychiatric conditions.

PUBLIC SIGNIFICANCE

The mortality in patients with anorexia nervosa (AN) is high and we show in our study that the mortality is doubled in the presence of psychiatric comorbidity particularly the first 10 years after diagnosis seen in both sexes and with suicide as a major cause of death. These findings stress the importance of detection and treatment of psychiatric comorbidities alongside the eating disorder to prevent fatal outcome.

Registration of Amyotrophic Lateral Sclerosis: Validity in the Danish National Patient Registry

Purpose

Health care databases are a valuable source for epidemiological research on amyotrophic lateral sclerosis (ALS) if diagnosis codes are valid. We evaluated the validity of the diagnostic codes for ALS in the Danish National Patient Registry (DNPR).

Patients and Methods

We obtained data from the DNPR for all adult (>17 years) patients registered with ALS in Denmark between 1987 and 2022 (median population of 4.2 million during the study period). We randomly selected adult patients living in the North Denmark Region and Central Denmark Region (median population 1.4 million), with a primary discharge diagnosis code of ALS, diagnosed at three departments of neurology. We retrieved and reviewed medical records and estimated the positive predictive value (PPV) of the ALS diagnosis.

Results

Over 36 years, we identified 5679 patients. From the validation cohort of 300 patients, we were able to retrieve 240 (80%) medical records, and 215 ALS diagnoses were confirmed. The overall positive predictive value was 89.6% (95% confidence interval (CI): 85.1-92.8). The highest PPV was achieved for diagnoses registered for patients aged ≥70 years (93.8; 95% CI: 86.2-97.3) compared to patients <60 years (83.4; 95% CI: 73.3-90.7).

Conclusion

We found a high PPV of primary diagnostic codes for ALS from Danish departments of neurology, demonstrating high validity. Thus, the DNPR is a well-suited data source for large-scale epidemiological research on ALS.

Pediatric health service utilization at tertiary hospitals in Denmark 2000-2018

Pediatric health service differs between and within countries. To prioritize limited resources, data-driven studies on pediatric tertiary hospital contacts are warranted. This population-based register study identified all contacts with four Danish tertiary hospitals 2000-2018 by 0-17-year-old patients. During 2000-2018, 2,496,001 individuals resided in Denmark while 0-17 years old, and the study described 829,562 inpatient and 3,932,744 outpatient contacts at tertiary hospitals by hospital, sex, age, diagnosis, department, and residence. Male patients accounted for more contacts overall (inpatient 55.51%, outpatient 52.40%) and more contacts with severe chronic disease (inpatient 56.24%, outpatient 54.41%). Median (interquartile range) patient age was 3.09 (0.26-9.96) and 8.48 (2.78-13.70) years for in- and outpatient contacts. Overall, 28.23% and 21.02% of in- and outpatient contacts included a diagnosis of a severe chronic disease, but the proportions differed across hospitals. A pattern of pediatric healthcare directed towards less severe diseases was observed: While the total number of outpatient visits at tertiary hospitals increased from 2000 to 2018, the proportion of these contacts which had a diagnosis of a severe chronic disease decreased. Future comparisons between hospitals regarding pediatric outcomes should consider potential differences in terms of uptake and diagnosis severity. Such findings may have implications for future pediatric organization, nationally and internationally.

Risk of post-injection endophthalmitis peaks within the first three injections of anti-vascular endothelial growth factor therapy: A nationwide registry-based study

PURPOSE

To report the incidence of post-injection endophthalmitis (PIE) and the cumulative risk associated with repeated injections of intravitreal anti-vascular endothelial growth factor (anti-VEGF).

METHODS

We employed nationwide registries in Denmark to include all individuals aged ≥40 years who received at least one intravitreal anti-VEGF injection in 2007-2022. Our primary endpoint PIE was identified using specific diagnostic codes for endophthalmitis and procedure codes for vitreous biopsy within 10 days prior to and 120 days post-injection. Patients were stratified according to the underlying diagnoses for which they received the treatment. The relative risk (RR) for PIE was calculated between groups based on the number of injections received by the patients.

RESULTS

We identified 60 825 patients who received intravitreal anti-VEGF treatment during study time, with a median age of 77.2 years and females constituting 58.1%. We identified 232 cases of PIE after 1 051 549 injections during follow-up, resulting in an incidence of 0.022% [95% CI 0.019%-0.025%]. Despite a linear growth in annual anti-VEGF use, the incidence remained stable at 0.020% [95% CI 0.017%-0.023%] from 2013 to 2022. Compared to patients receiving 1-3 injections, RR for patients receiving 4-20, 21-40, and >40 injections were 0.46 [95% CI 0.34-0.63], 0.32 [95% CI 0.21-0.50], and 0.54 [95% CI 0.36-0.81], respectively. Findings were similar across the different diagnoses.

CONCLUSIONS

Based on 16 years of nationwide registry data, this study identified a low and stable incidence of PIE. Notably, the highest risk of endophthalmitis was within the first three anti-VEGF injections.

Follow-Up Study of Effectiveness of 23-Valent Pneumococcal Polysaccharide Vaccine Against All-Type and Serotype-Specific Invasive Pneumococcal Disease, Denmark

As a follow-up to a previous study, we investigated vaccine effectiveness (VE) of 23-valent pneumococcal polysaccharide vaccine (PPSV23) against invasive pneumococcal disease (IPD) among 1,254,498 persons >65 years of age as part of a vaccination program in Denmark during April 2020-January 2023. We assessed VE by using a Cox regression model and adjusted for age, sex, and underlying conditions. Using nationwide data, we estimated a VE of PPSV23 against all-type IPD of 32% and against PPSV23-serotype IPD of 41%. Because this follow-up study had more statistical power than the original study, we also estimated VE against IPD caused by PPSV23-serotypes excluding serotype 3; serotype 3; serotype 8; serotype 22F; PPSV23 non-PCV15 serotypes; PPSV23 non-PCV20 serotypes; and IPD over time. Our findings suggest PPSV23 vaccination can protect persons >65 years of age against IPD caused by all serotypes or serotype groupings, except serotype 3.

Trends in cause-specific mortality among people with type 2 and type 1 diabetes from 2002 to 2019: a Danish population-based study

Background

Despite advances in primary and secondary prevention of cardiovascular disease, excess mortality persists within the diabetes population. This study explores the components of this excess mortality and their interaction with sex.

Methods

Using Danish registries (2002-2019), we identified residents aged 18-99 years, their diabetes status, and recorded causes of death. Applying Lexis-based methods, we computed age-standardized mortality rates (asMRs), mortality relative risks (asMRRs), and log-linear trends for cause-specific mortality.

Findings

From 2002 to 2019, 958,278 individuals died in Denmark (T2D: 148,620; T1D: 7830) during 84.4 M person-years. During the study period, overall asMRs declined, driven by reducing cardiovascular mortality, notably in men with T2D. Conversely, cancer mortality remained high, making cancer the leading cause of death in individuals with T2D. Individuals with T2D faced an elevated mortality risk from nearly all cancer types, ranging from 9% to 257% compared to their non-diabetic counterparts. Notably, obesity-related cancers exhibited the highest relative risks: liver cancer (Men: asMRR 3.58 (3.28; 3.91); Women: asMRR 2.49 (2.14; 2.89)), pancreatic cancer (Men: asMRR 3.50 (3.25; 3.77); Women: asMRR 3.57 (3.31; 3.85)), and kidney cancer (Men: asMRR 2.10 (1.84; 2.40); Women: asMRR 2.31 (1.92; 2.79)). In men with type 2 diabetes, excess mortality remained stable, except for dementia. In women, diabetes-related excess mortality increased by 6-17% per decade across all causes of death, except cardiovascular disease.

Interpretation

In the last decade, cancer has emerged as the leading cause of death among individuals with T2D in Denmark, emphasizing the need for diabetes management strategies incorporating cancer prevention. A sex-specific approach is crucial to address persistently higher relative mortality in women with diabetes.

Funding

Supported by Steno Diabetes Center Aarhus, which is partially funded by an unrestricted donation from the Novo Nordisk Foundation, and by The Danish Diabetes Academy.

Towards more comprehensive nationwide familial aggregation studies in Denmark: The Danish Civil Registration System versus the lite Danish Multi-Generation Register

AIM

Linking information on family members in the Danish Civil Registration System (CRS) with information in Danish national registers provides unique possibilities for research on familial aggregation of diseases, health patterns, social factors and demography. However, the CRS is limited in the number of generations that it can identify. To allow more complete familial linkages, we introduce the lite Danish Multi-Generation Register (lite MGR) and the future full Danish MGR that is currently being developed.

METHODS

We generated the lite MGR by linking the current version of the CRS with historical versions stored by the Danish National Archives in the early 1970s, which contain familial links not saved in the current CRS. We describe and compare the completeness of familial links in the lite MGR and the current version of the CRS. We also describe planned procedures for generating the full MGR by linking the current CRS with scanned archived records from Parish Registers.

RESULTS

Among people born in Denmark in 1960 or later, the current CRS contains information on both parents. However, it has limited parental information for people born earlier. Among the 732,232 people born in Denmark during 1950-1959, 444,084 (60.65%) had information on both parents in the CRS. In the lite MGR, it was 560,594 (76.56%).

CONCLUSIONS

The lite MGR offers more complete information on familial relationships than the current CRS. The lite and full MGR will offer an infrastructure tying together existing research infrastructures, registers and biobanks, raising their joint research value to an unparalleled level.

Parous women perform less moderate to vigorous physical activity than their nulliparous peers: a population-based study in Denmark

OBJECTIVES

The World Health Organization (WHO) highlights parous women as a key population for monitoring trends of physical activity (PA). We aimed to estimate the proportion of Danish women non-adhering to WHO PA guidelines in parous women compared with nulliparous women and to describe leisure-time PA intensity in each of these groups.

STUDY DESIGN

Cross-sectional study.

METHODS

This population-based study builds on a sample of 27,668 women aged 16-40 years from the Danish National Health Survey 2021. These data were linked with childbirth data from the Danish National Birth Registry. The primary outcome was self-reported weekly hours of moderate to vigorous leisure-time PA (MVPA) dichotomized into: (i) adhering to WHO guidelines for MVPA or (ii) not adhering to WHO guidelines for MVPA. Binomial regression analysis was used to calculate prevalence proportions (PP) and prevalence proportion ratios (PPR).

RESULTS

Of the 27,668 women, a total of 20,022 were included; 9338 (46.6%) parous women and 10,684 (53.4%) nulliparous women. The PP of women non-adhering to WHO PA guidelines was 63.8% (95% CI 62.9-64.8) for parous and 51.3% (95% CI 50.4-52.3) for nulliparous women, corresponding to a PPR of 1.24 (95% CI 1.21; 1.27).

CONCLUSIONS

The proportion of parous women who did not adhere to WHO PA guidelines for MVPA was 24% higher than that of nulliparous women. This highlights parous women as a subgroup of the adult population at increased risk of non-adherence to WHO PA guidelines. These findings call for future research to inform new strategies aiming to promote PA in parous women.

Homelessness, psychiatric disorders, and violence in Denmark: a population-based cohort study

BACKGROUND

Homelessness is associated with adverse health and social outcomes. People experiencing homelessness have been found to have a high risk of violent crime victimisation as well as high prevalence of psychiatric disorders. It is poorly understood whether experiencing homelessness is associated with additional risks of violent offending and whether psychiatric disorders contribute to these risks. We examined the association between homelessness, psychiatric disorders, and first violence offence leading to conviction.

METHODS

We did a nationwide, register-based cohort study of all Danish residents who were alive at least 1 day during the study period, born between Jan 1, 1980, and Dec 31, 2006, and aged 15 years or older retrieved from the Danish Civil Registration System, which was linked to registers with information on homelessness, health care, and criminality. The exposure was any experience of homelessness, which was defined as having at least one contact with a homeless shelter during the study period. The outcome was first violent offence leading to a conviction. We calculated incidence rates per 10 000 person-years, incidence rate ratios (IRRs) using Poisson regression analysis, and probability of conviction of a violent offence using an Aalen-Johansen estimator. Analyses were stratified by sex and adjusted for calendar year of the study period, age, other sociodemographic factors, and psychiatric disorders.

FINDINGS

The study cohort included 1 786 433 Danish residents aged 15-42 years living in Denmark at some point from Jan 1, 2001, to Dec 31, 2021, contributing to 21 336 322 person-years at risk, of whom 57 084 (3·2%) individuals had their first violent offence leading to conviction during follow-up. 10 years after their first contact with a homeless shelter, 22·9% (95% CI 21·6-24·2) of men and 7·7% (6·8-8·7) of women had committed at least one violent crime leading to conviction. The fully adjusted IRRs of a violent offence leading to conviction were 4·8 (4·5-5·1) in men and 6·3 (5·6-7·2) in women experiencing homelessness compared with individuals who had not experienced homelessness. The IRR for a violent offence leading to conviction was highest in individuals experiencing homelessness and having co-occurring psychiatric disorders compared with those not experiencing homelessness and without co-occurring psychiatric disorders, especially drug use disorders (IRR in those experiencing homelessness and having a drug use disorder: 15·3 [14·1-16·7] in men and 40·1 [33·9-47·5] in women compared with individuals not experiencing homelessness and having no drug use disorder).

INTERPRETATION

Individuals experiencing homelessness had higher risks of a violent offence leading to conviction than those who had not experienced homelessness. In addition to preventing homelessness, public health and policy should consider how to reduce the risk of adverse outcomes in people experiencing homelessness.

FUNDING

Lundbeck Foundation.

Incidence of late recurrence and second primary cancers 5-10 years after non-metastatic colorectal cancer

The fraction of patients who are cancer-free survivors 5 years after curative-intended surgery for colorectal cancer (CRC) is increasing, suggesting that extending surveillance beyond 5 years may be indicated. Here we estimate the incidence of late recurrence, metachronous CRC, and second primary cancers 5-10 years postoperative. All patients resected for UICC stage I-III CRC in Denmark through 2004-2013 were identified. Through individual-level linkage of nationwide health registry data, recurrence status was determined using a validated algorithm. Cancer-free survivors 5 years after surgery, were included. Cumulative incidence functions (CIF) of late recurrence, metachronous CRC, and second primary cancer 5-10 years postoperative were constructed. Subdistribution hazards ratios (sHR) were computed using Fine-Gray regression. Among 8883 patients, 370 developed late recurrence (5-10-year CIF = 4.1%, 95%CI: 3.7%-4.6%), 270 metachronous CRC (5-10-year CIF = 3.0%, 95%CI: 2.7%-3.4%), and 635 a second primary cancer (5-10-year CIF = 7.2%, 95%CI: 6.7%-7.7%). The risk of late recurrence was reduced for patients operated in 2009-2013 compared to 2004-2008 (2.9% vs. 5.6%, sHR = 0.52, 95% CI: 0.42-0.65). The risk of metachronous CRC was likewise reduced from 4.1% to 2.1% (sHR = 0.50, 95%CI: 0.39-0.65). While the risk of second primary cancer did not change between 2009-2013 and 2004-2008 (7.1% vs. 7.1%, sHR = 0.98, 95% CI: 0.84-1.15). Using nation-wide 10-year follow-up data, we document that the incidences of late recurrence and metachronous CRC are low and decreasing from 2004 to 2013. Thus, despite increasing numbers of long-term cancer survivors, the data do not advocate for extending CRC-specific surveillance beyond 5 years.

Longitudinal HbA1c patterns before the first treatment of diabetes in routine clinical practice: A latent class trajectory analysis

AIMS

To examine the longitudinal heterogeneity of HbA1c preceding the initiation of diabetes treatment in clinical practice.

METHODS

In this population-based study, we used HbA1c from routine laboratory and healthcare databases. Latent class trajectory analysis was used to classify individuals according to their longitudinal HbA1c patterns before first glucose-lowering drug prescription irrespective of type of diabetes.

RESULTS

Among 21,556 individuals initiating diabetes treatment during 2017-2018, 20,733 (96 %) had HbA1c measured (median 4 measurements [IQR 2-7]) in the 5 years preceding treatment initiation. Four classes with distinct HbA1c trajectories were identified, with varying steepness of increase in HbA1c. The largest class (74 % of the individuals) had mean HbA1c above the 48 mmol/mol threshold 9 months before treatment initiation. Mean HbA1c was 52 mmol/mol (95 % CI 52-52) at treatment initiation. In the remaining three classes, mean HbA1c exceeded 48 mmol/mol almost 1.5 years before treatment initiation and reached 79 mmol/mol (95 % CI 78-80), 105 mmol/mol (95 % CI 104-106), and 137 mmol/mol (95 % CI 135-140) before treatment initiation.

CONCLUSION

We identified four distinct longitudinal HbA1c patterns before initiation of diabetes treatment in clinical practice. All had mean HbA1c levels exceeding the diagnostic threshold many months before treatment initiation, indicating therapeutic inertia.

Fifteen-year temporal changes in rates of acute kidney injury among children in Denmark

BACKGROUND

We aimed to examine temporal changes in the annual rate of acute kidney injury (AKI) in Danish children and associated changes in patient characteristics including potential underlying risk factors.

METHODS

In this population-based cohort study, we used plasma creatinine measurements from Danish laboratory databases to identify AKI episodes in children aged 0-17 years from 2007 to 2021. For each child, the first AKI episode per calendar year was included. We estimated the annual crude and sex- and age-standardized AKI rate as the number of children with an AKI episode divided by the total number of children as reported by census numbers. Using Danish medical databases, we assessed patient characteristics including potential risk factors for AKI, such as use of nephrotoxic medication, surgery, sepsis, and perinatal factors.

RESULTS

In total, 14,200 children contributed with 16,345 AKI episodes over 15 years. The mean annual AKI rate was 148 (95% CI: 141-155) per 100,000 children. From 2007 to 2021, the annual AKI rate demonstrated minor year-to-year variability without any discernible overall trend. The highest AKI rate was recorded in 2007 at 174 (95% CI: 161-187) per 100,000 children, while the lowest rate occurred in 2012 at 129 (95% CI: 118-140) per 100,000 children. In 2021, the AKI rate was 148 (95% CI: 141-155) per 100,000 children. Characteristics of children with AKI were similar throughout the study period.

CONCLUSION

The rate of AKI among Danish children was stable from 2007 to 2021 with little variation in patient characteristics over time.

Cost of out-of-hospital cardiac arrest survivors compared with matched control groups

INTRODUCTION

Societal costs of out-of-hospital cardiac arrest (OHCA) survivors may be extensive due to high health care utilization and sick leave. Knowledge of the costs of OHCA survivors may guide decision-makers to prioritize health resources.

AIM

The aims of the study were to evaluate the costs of OHCA survivors from a societal perspective, and to compare these costs to the costs of individuals with non-cardiac arrest myocardial infarction (MI) and individuals with no cardiac disease (non-CD).

METHODS

From the Danish OHCA Registers, survivors, with a cardiac arrest between 2005-2018 were identified. Each case was assigned one MI control and one non-CD control, matched on gender and age. Based on register data, costs of healthcare utilization, sick leave, vocational rehabilitation, disability pension and other social benefits one year before event and five years after, were estimated.

RESULTS

In total 5,646 OHCA survivors were identified with associated control groups. The mean costs for OHCA survivors during the 6-year period were €119,106 (95%CI: 116,297-121,916), with €83,472 (95%CI: 81,392-85,552) being healthcare costs. Mean costs of OHCA survivors were €49,132 higher than the MI-control group and €100,583 higher than the non-CD control group.

CONCLUSIONS

Total costs of OHCA survivors were considerably higher than costs of MI- and non-CD controls. Hospital costs were highest during the first year after event, and work inability during the second to fifth year with sick leave and later disability pension as main burdens.

Changes in Symptoms and General Well-being After Reversal of Roux-en-Y Gastric Bypass: A Questionnaire Survey

PURPOSE

After Roux-en-Y gastric bypass (RYGB), few patients develop severe complications, which ultimately may require reversal of RYGB. We aimed to examine the effect of reversal of RYGB on symptoms and well-being.

MATERIALS AND METHODS

Via contact to medical and surgical departments treating patients with RYGB, we identified 18 patients, who had undergone reversal, 2009-2019. We conducted a Danish, nationwide questionnaire survey concerning symptoms before and after reversal of the RYGB including the patients' own perceptions of their well-being.

RESULTS

Fourteen patients responded to the questionnaire (86% female; median age at RYGB, 36.2 years [IQR, 30.9-38.6 years]). The median time from RYGB to reversal was 5.8 years (IQR, 5.1-7.5 years). After RYGB, 13 patients (93%) reported abdominal pain, while 12 patients still had abdominal pain after reversal. Six out of 11 patients (45%) reported complete remission of dumping/post-bariatric hypoglycemia (PBH) after reversal. Malabsorption disappeared in 10 out of 11 patients (90%). Reversal had minor effect on neuropathy. The median weight loss from RYGB was 61 kg (IQR, 56-75 kg), while the median weight regain after reversal was 30 kg (IQR, 13-46 kg). Regarding the well-being, 72 of the patients felt better or much better after reversal.

CONCLUSION

In total, 72% of the patients felt better or much better after reversal of RYGB, though some still had RYGB-related symptoms. The reversal relieved dumping/PBH and malabsorption, but not abdominal pain and neuropathy. Finally, half of the weight loss was regained after reversal. Reversal of RYGB may be an option in highly selected cases.

Inhaled corticosteroid treatment and pneumonia in patients with chronic obstructive pulmonary disease - nationwide development from 1998 to 2018

Background

A decreasing use of inhaled corticosteroids (ICS) in patients with a hospital-registered diagnosis of chronic obstructive pulmonary disease (COPD) has recently been documented in Denmark. ICS treatment is not recommended in patients with high pneumonia risk, and we aimed to assess the development of ICS treatment in relation to pneumonia occurrence.

Methods

Annual nationwide register-based cross-sectional studies from 1998 to 2018 including all patients ≥40 years of age with a hospital-registered ICD-10 diagnosis of COPD on the 31st of December each year. We calculated the annual proportion of patients with at least one outpatient pneumonia (redeemed prescription of relevant antibiotics) or pneumonia hospitalization (hospitalization or ER visit), and stratified by ICS dose (No ICS, low dose, medium dose, or high dose).

Results

The study population increased from 35,656 patients in 1998 to 99,057 patients in 2018. The annual proportion of patients experiencing a pneumonia decreased from 69.4% to 55.2%. The proportion of patients with at least one outpatient pneumonia, but no hospitalization, decreased (59.2% to 46.2%). The overall proportion of patients with at least one pneumonia hospitalization remained unchanged (10.2% to 9.0%), but this proportion increased in patients in high dose ICS (9.9% to 14.6%). The overall proportion of patients in high dose treatment decreased (12.7% to 5.7%), but not in patients with pneumonia hospitalization (16.5% to 15.1).

Conclusions

Our study demonstrates a nationwide decrease from 1998 to 2018 in the proportion of patients who redeemed a prescription for antibiotics used mainly for respiratory tract infections, which may reflect a decrease in the number of outpatient pneumonias. This decrease was largely caused by an increase in the number of patients without pneumonia. No differences over time were seen regarding hospitalization-requiring pneumonia. High dose ICS treatment was unchanged in patients with hospitalization-requiring pneumonia.

Urban-rural and socio-economic differences in inhaled corticosteroid treatment for chronic obstructive pulmonary disease: A nationwide register-based cross-sectional study

BACKGROUND

Urban-rural disparities within chronic obstructive pulmonary disease (COPD) have been documented in USA, but not in Europe. Inhaled corticosteroids (ICS) are widely used in COPD despite strict recommendations. We aimed to investigate urban-rural and socioeconomic differences in ICS treatment for COPD.

METHODS

A Danish nationwide register-based cross-sectional study. All patients alive on the December 31, 2018 with a J44 ICD-10 diagnosis code (COPD) were included (99,057 patients). Daily average ICS dose was calculated from the accumulated ICS use during 2018 based on redeemed prescriptions. Patients were divided into groups: No ICS, low dose ICS, medium dose ICS, high dose ICS. A multinomial logistic regression model including educational level, co-habitation status, age, and sex was performed with "No ICS" as reference group.

RESULTS

Compared to capital municipalities, living in other municipality types was associated with an increased probability of receiving medium and high dose ICS treatment, and increasing odds ratios (ORs) were seen with increasing ICS dose (medium dose ICS: ORs between 1.31 (95 % confidence interval (CI) 1.24-1.38) and 1.35 (95%CI 1.28-1.41), high dose ICS: ORs between 1.73 (95%CI 1.59-1.88) and 1.80 (95%CI 1.68-1.92)). Patients had increased probability of receiving ICS treatment if they were female, were co-habiting, or had completed only primary education.

CONCLUSION

Patients with a hospital-registered COPD diagnosis in non-capital municipalities receive more ICS, and in higher doses, compared to patients in capital municipalities. This is the first study to confirm that such urban-rural differences exist in Europe, and further research on this area is warranted.

Blood laboratory analyses preceding in-hospital cardiac arrest: A matched case-control study

BACKGROUND

Whether blood laboratory analyses differ in patients who later suffer in-hospital cardiac arrest (IHCA) compared to other hospitalised patients remains unknown. The aim of this study was to describe pre-arrest sampling frequencies, results, and trends in blood laboratory analyses in patients with IHCA compared to controls.

METHODS

This study was a matched case-control study using national registries in Denmark. Cases were defined as patients with IHCA from 2017 to 2021. Controls were defined as hospitalised patients and were matched on age, sex, and date and length of admission. Data on a total of 51 different blood laboratory analyses were obtained. The laboratory analyses of primary interest were lactate, sodium, potassium, and haemoglobin. The index time for cases was defined as the time of cardiac arrest, and a corresponding index time was defined for controls based on the time to cardiac arrest for their corresponding case. Blood sampling frequencies were reported for blood laboratory analyses obtained either within the last 24 h before the index time or between the time of hospital admission and the index time. Blood sampling results were reported for blood laboratory analyses obtained within the last 24 h before the index time.

RESULTS

A total of 9268 cases and 92,395 controls were included in this study. Cases underwent more frequent sampling of all blood laboratory analyses compared to controls. This higher sampling frequency was more pronounced for lactate compared to sodium, potassium, or haemoglobin. The last measured lactate was higher in cases (median [IQR]: 2.3 [1.3, 4.9]) compared to controls (median [IQR]: 1.3 [0.9, 2.0]). Differences in sodium, potassium, and haemoglobin were negligible. The proportion of abnormally elevated levels of lactate and potassium increased as time to cardiac arrest decreased; no such effect was seen in controls. No temporal trend was evident for sodium or haemoglobin.

CONCLUSIONS

Patients with IHCA undergo more frequent blood sampling prior to IHCA and have higher levels of lactate compared to matched controls.

Characteristics and outcomes for general anesthesia in Denmark

BACKGROUND

General anesthesia is common, but concerns regarding post-operative complications and mortality remain. No study has described the Danish patient population undergoing general anesthesia on a national level. The aim of this study was to describe the characteristics and outcomes of patients undergoing general anesthesia in Denmark.

METHODS

This study was a registry-based observational cohort study of adult patients (≥18 years) undergoing general anesthesia in Denmark during 2020 and 2021. Data from nationwide registries covering patient characteristics, anesthesia and procedure information, and patient outcomes were combined. Descriptive statistics were used to present findings, both overall and in subgroups based on the American Society of Anesthesiologists (ASA) classification.

RESULTS

We identified 453,133 cases of general anesthesia in 328,951 unique patients. The median age was 57 years (quartiles: 41, 71), and 242,679 (54%) were females. Data on ASA classification were missing for less than 1% of the population, and ASA II was the most prevalent ASA classification (49%). Among cases of general anesthesia, 0.1% experienced a stroke, 0.2% had in-hospital cardiac arrest, and 3.9% had a stay in the intensive care unit within 30 days. Mortality at 30 days and 1 year were 1.8% and 6.3%, respectively, increasing with a higher ASA classification.

CONCLUSION

This study offers the first comprehensive overview of adult patients undergoing general anesthesia in Denmark. Post-anesthesia complications were few and increased with ASA classification.

Evaluation of Left Truncation and Censoring When Changing the Use of the International Classification of Diseases Eighth Revision Codes to Tenth Revision Codes in the Danish National Patient Registry

Purpose

In the Danish National Patient Registry (DNPR), covering all Danish hospitals and widely used in research, diseases have been recorded using International Classification of Diseases (ICD) codes, transitioning from the Eighth to the Tenth revision in 1994. Uncertainty exists regarding whether including ICD-8 codes alongside ICD-10 is needed for complete disease identification. We assessed the extent of left-truncation and left-censoring in the DNPR arising from omitting ICD-8 codes.

Patients and Methods

We sampled 500,000 Danes ≥40 years of age in 1995, 2010, and 2018. From the DNPR, we identified cardiovascular, endocrine, gastrointestinal, neurological, pulmonary, rheumatic, and urogenital diseases as well as fractures. We obtained the number of people with a disease recorded with ICD-8 codes only (ie, the ICD-8 record would be left-truncated by not using ICD-8 codes), ICD-8 plus ICD-10 codes (ie, the ICD-8 record would be left-censored by not using ICD-8 codes), and ICD-10 codes only. For each ICD group, we calculated the proportion of people with the disease relative to the total sample (ie, 500,000 people) and the total number of people with the disease across all ICD groups.

Results

Overall, the left-truncation issue decreased over the years. Relative to all people with a disease, the left-truncated proportion was for example 59% in 1995 and <2% in 2018 for diabetes mellitus; 93% in 1995, and 54% in 2018 for appendicitis. The left-truncation issue increased with age group for most diseases. The proportion of disease records left-censored by not using ICD-8 codes was generally low but highest for chronic diseases.

Conclusion

The left-truncation issue diminished over sample years, particularly for chronic diseases, yet remained rather high for selected surgical diseases. The left-truncation issue increased with age group for most diseases. Left-censoring was overall a minor issue that primarily concerned chronic diseases.

Incidence and Prevalence of Fibrous Dysplasia/McCune-Albright Syndrome: A Nationwide Registry-Based Study in Denmark

CONTEXT

Fibrous dysplasia/McCune-Albright syndrome (FD/MAS) is a rare genetic disorder. Incidence and prevalence are not well-studied. Epidemiological research is complicated by the rarity of FD/MAS, absence of registries, heterogeneous presentation, and possibly asymptomatic phenotype. FD/MAS may present with FGF23-mediated hypophosphatemia, of which the epidemiology is also unclear.

OBJECTIVE

Evaluate incidence and prevalence of FD/MAS and FD/MAS-related hypophosphatemia.

METHODS

This cohort study based on the nationwide Danish National Patient Registry from 1995-2018, included patients identified by ICD-10 codes M85.0 (monostotic FD [MFD]) and Q78.1 (polyostotic FD [PFD]/MAS). Incidence rates and prevalence were calculated and stratified by sex, age, calendar period, and diagnosis code. Cases were screened for FD-associated hypophosphatemia by diagnosis code E.83 (disorder of mineral metabolism) and dispatched vitamin D analogues.

RESULTS

A total of 408 patients were identified, 269 with MFD (66%), 139 with PFD/MAS (34%), comparable between sexes. Incidence of FD/MAS demonstrated increasing secular trend with a rate of 3.6 per 1 000 000 person-years (95% CI: 2.9, 4.5) in 2015-2018. Incidence peaked between age 11 and 20. Prevalence of FD/MAS increased over time to 61.0 (95% CI: 54.6, 67.4) per 1 000 000 persons in 2018. The incidence rate of MFD was 1.5-fold that of PFD/MAS in the first decade, rising to 2.5-fold in the last decade. No FD/MAS cases were registered with diagnosis code or treatment for hypophosphatemia.

CONCLUSION

FD/MAS is rare, diagnosis peaks during adolescence without sex predominance, and MFD is most prevalent. Hypophosphatemia may be underdiagnosed and undertreated, or it may be underregistered, comparing this study to literature.

Identification of patients' smoking status using an explainable AI approach: a Danish electronic health records case study

BACKGROUND

Smoking is a critical risk factor responsible for over eight million annual deaths worldwide. It is essential to obtain information on smoking habits to advance research and implement preventive measures such as screening of high-risk individuals. In most countries, including Denmark, smoking habits are not systematically recorded and at best documented within unstructured free-text segments of electronic health records (EHRs). This would require researchers and clinicians to manually navigate through extensive amounts of unstructured data, which is one of the main reasons that smoking habits are rarely integrated into larger studies. Our aim is to develop machine learning models to classify patients' smoking status from their EHRs.

METHODS

This study proposes an efficient natural language processing (NLP) pipeline capable of classifying patients' smoking status and providing explanations for the decisions. The proposed NLP pipeline comprises four distinct components, which are; (1) considering preprocessing techniques to address abbreviations, punctuation, and other textual irregularities, (2) four cutting-edge feature extraction techniques, i.e. Embedding, BERT, Word2Vec, and Count Vectorizer, employed to extract the optimal features, (3) utilization of a Stacking-based Ensemble (SE) model and a Convolutional Long Short-Term Memory Neural Network (CNN-LSTM) for the identification of smoking status, and (4) application of a local interpretable model-agnostic explanation to explain the decisions rendered by the detection models. The EHRs of 23,132 patients with suspected lung cancer were collected from the Region of Southern Denmark during the period 1/1/2009-31/12/2018. A medical professional annotated the data into 'Smoker' and 'Non-Smoker' with further classifications as 'Active-Smoker', 'Former-Smoker', and 'Never-Smoker'. Subsequently, the annotated dataset was used for the development of binary and multiclass classification models. An extensive comparison was conducted of the detection performance across various model architectures.

RESULTS

The results of experimental validation confirm the consistency among the models. However, for binary classification, BERT method with CNN-LSTM architecture outperformed other models by achieving precision, recall, and F1-scores between 97% and 99% for both Never-Smokers and Active-Smokers. In multiclass classification, the Embedding technique with CNN-LSTM architecture yielded the most favorable results in class-specific evaluations, with equal performance measures of 97% for Never-Smoker and measures in the range of 86 to 89% for Active-Smoker and 91-92% for Never-Smoker.

CONCLUSION

Our proposed NLP pipeline achieved a high level of classification performance. In addition, we presented the explanation of the decision made by the best performing detection model. Future work will expand the model's capabilities to analyze longer notes and a broader range of categories to maximize its utility in further research and screening applications.

DARE-ISC model for prediction of 1-year ischaemic stroke risk in the general population and atrial fibrillation patients: a Danish nationwide cohort study

OBJECTIVES

To develop a risk assessment model (DAnish REgister Ischaemic Stroke Classifier, DARE-ISC) for predicting 1-year primary ischaemic stroke/systemic embolism (SE) in the general population. Secondly, to validate the accuracy DARE-ISC in atrial fibrillation (AF) patients where well-established models and risk scores exist.

DESIGN

Retrospective cohort study. DARE-ISC was developed using gradient boosting decision trees with information from 375 covariates including baseline information on relevant diagnoses, demographic characteristics, registered health-services, lifestyle-related covariates, hereditary stroke components, drug prescriptions and stress proxies.

SETTING

Danish nationwide registries.

PARTICIPANTS

All Danish individuals aged ≥18 from 2010 to 2017 (n=35 519 348 person-years). The model was trained on the 2010-2016 cohorts with validation in the 2017 cohort.

PRIMARY AND SECONDARY OUTCOME MEASURES

Model optimisation and validation were performed through comparison of the area under the receiver operating characteristic curve (AUC) and average precision scores. Additionally, the relative importance of the model covariates was derived using SHAP values.

RESULTS

DARE-ISC had an AUC (95% CI) of 0.874 (0.871 to 0.876) in the general population. In AF patients, DARE-ISC was superior to the GARFIELD-AF risk model and CHA2DS2-VASc score with AUC of 0.779 (95% CI 0.75 to 0.806), 0.704 (95% CI 0.674 to 0.732) and 0.681 (95% CI 0.652 to 0.709), respectively. Furthermore, in AF patients, DARE-ISC had an average threefold and fourfold higher ratio of correctly identified strokes compared with the GARFIELD-AF risk model and CHA2DS2-VASc score, as indicated by average precision scores of 0.119, 0.041 and 0.034, respectively.

CONCLUSIONS

DARE-ISC had a very high stroke prediction accuracy in the general population and was superior to the GARFIELD-AF risk model and CHA2DS2-VASc score for predicting ischaemic stroke/SE in AF patients.

Trends in the Use of Medications for Secondary Ischemic Stroke Prevention in Denmark, 2005-2021

BACKGROUND AND OBJECTIVES

Understanding trends in the use of medications for secondary stroke prevention is crucial for identifying areas for improvement in stroke care. We examined the use of lipid-lowering, antihypertensive, glucose-lowering, oral anticoagulant, and antiplatelet medications after ischemic stroke hospitalization, from 2005 to 2021.

METHODS

Using nationwide registries in Denmark, we identified a cohort of patients discharged from hospital with a first-time or recurrent ischemic stroke (N = 150,744). Stratified by calendar year, we ascertained the 180-day probability of filling a prescription for the abovementioned medications after discharge. We further assessed factors associated with medication use.

RESULTS

From 2005 to 2021, lipid-lowering medication use increased from 58.3% to 82.0%; atorvastatin use rose from 2.1% to 64.8% and simvastatin use decreased from 55.7% to 8.6%. Antihypertensive medication use remained stable, at approximately 89%, and various antihypertensive classes were used comparably. Glucose-lowering medication use increased from 71.5% in 2005 to 84.1% in 2021, driven primarily by an increase in metformin use (from 28.0% to 59.5%). Use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors continually increased (from 1.7% to 17.5% and from 0.5% to 17.3%, respectively) between 2015 and 2021. Anticoagulant medication use rose from 45.9% in 2005 to 87.0% in 2021, primarily because of increased use of direct oral anticoagulant medications starting around 2010 and a decline in warfarin use. Antiplatelet use remained consistently high, at approximately 95%. Trends were consistent across subgroups of interest; however, overall medication use was lower in older patients (65 years and older), patients with severe stroke, and patients with neurologic and psychiatric comorbidities.

DISCUSSION

Despite increasing trends in the use of 3 of 5 medication classes, the overall use of lipid-lowering, glucose-lowering, and oral anticoagulant medications was somewhat lower than expected according to clinical guidelines, particularly among older patients with more severe stroke and other comorbidities. The relatively low use in these subgroups may signify appropriate clinical decision making in consideration of frequent contraindications and reduced life expectancy or highlight potential areas of improvement for the care of patients with recent ischemic stroke.

VEGF Inhibition Associates With Decreased Risk of Mortality in Patients With Neovascular Age-related Macular Degeneration

Purpose

Controversy exists regarding the systemic safety of intravitreal VEGF inhibitors in the treatment of neovascular age-related macular degeneration (nAMD). We aimed to investigate the potential impact of VEGF inhibitor treatment on the risk of all-cause mortality and cardiovascular disease (CVD) among patients with nAMD.

Design

A nationwide register-based cohort study with 16 years follow-up.

Participants

Patients with nAMD exposed with VEGF inhibitors (n = 37 733) and unexposed individuals without nAMD (n = 1 897 073) aged ≥ 65 years residing in Denmark between January 1, 2007, and December 31, 2022.

Methods

Cox proportional hazards analysis was conducted to assess the effect of intravitreal VEGF inhibitor treatment on all-cause mortality and incident CVD.

Main Outcome Measures

In a predefined analysis plan we defined primary outcomes as hazard ratios (HRs) of all-cause mortality and a composite CVD endpoint in patients with nAMD treated with VEGF inhibitors compared with individuals without nAMD. The secondary outcomes encompassed analyses that explored the impact of the number of doses and the association between exposure and outcome over a specific time period.

Results

Overall, 63.7% of patients with nAMD were women with an average age of 69.9 years (interquartile range 65.0-76.0 years). Patients exposed to VEGF inhibitors demonstrated a reduced risk of all-cause mortality compared with individuals without nAMD (HR, 0.79; 95% confidence interval [CI], 0.78-0.81), and an increased risk of composite CVD (HR, 1.04; 95% CI, 1.01-1.07). The decreased risk of all-cause mortality persisted, but there was no significant association between VEGF inhibitor treatment and CVD when patients with nAMD were grouped by the number of doses or considered exposed within 60 days postinjection.

Conclusions

Our study revealed a decreased risk of all-cause mortality and a 4% increased risk of CVD among patients with nAMD exposed with VEGF inhibitors. The decreased risk of mortality is unlikely to be directly pathophysiologically related to VEGF inhibitor treatment. Instead, we speculate that patients undergoing VEGF inhibitor treatment are, on average, individuals in good health with adequate personal resources. Therefore, they also have a higher likelihood of overall survival. These findings strongly support the safety of VEGF inhibitor treatment in terms of all-cause mortality and CVD among patients with nAMD.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Risk and adverse clinical outcomes of thrombocytopenia among patients with solid tumors-a Danish population-based cohort study

BACKGROUND

Knowledge about thrombocytopenia among patients with solid tumors is scarce. We examined the risk of thrombocytopenia among patients with solid tumors and its association with adverse outcomes.

METHODS

Using Danish health registries, we identified all patients with incident solid tumors from 2015-2018 (n = 52,380) and a platelet count measurement within 2 weeks prior to or on their cancer diagnosis date. The risk of thrombocytopenia was categorized as grades 0 (any platelet count × 109/L): <150; 1: <100; 2: <75; 3: <50; 4: <25, and 5: <10. To study the outcomes, each patient with thrombocytopenia was matched with up to five cancer patients without thrombocytopenia by age, sex, cancer type, and stage. Cox regression was used to compute hazard ratios (HRs) of bleeding, transfusion, or death, adjusting for confounding factors.

RESULTS

The 1-year risk of thrombocytopenia was 23%, increasing to 30% at 4 years. This risk was higher in patients receiving chemotherapy (43% at 1 year and 49% at 4 years). Overall, patients with thrombocytopenia had higher 30-days rates of bleeding (HR = 1.72 [95% confidence interval, CI: 1.41-2.11]). Thrombocytopenia was also associated with an increased rate of transfusion, and death, but some of the risk estimates were imprecise.

CONCLUSIONS

The risk of thrombocytopenia was substantial among patients with solid tumors and associated with adverse outcomes.

Influence of multimorbidity and socioeconomic position on long-term healthcare utilization and prognosis in patients after cardiac resynchronization therapy implantation

Aims

We aimed to investigate the influence of socioeconomic position (SEP) and multimorbidity on cross-sectional healthcare utilization and prognosis in patients after cardiac resynchronization therapy (CRT) implantation.

Methods and results

We included first-time CRT recipients with left ventricular ejection fraction ≤35% implanted between 2000 and 2017. Data on chronic conditions, use of healthcare services, and demographics were obtained from Danish national administrative and health registries. Healthcare utilization (in- and outpatient hospitalizations, activities in general practice) was compared by multimorbidity categories and SEP by using a negative binomial regression model. The association between SEP, multimorbidity, and prognostic outcomes was analysed using Cox proportional hazards regression. We followed 2007 patients (median age of 70 years), 79% were male, 75% were on early retirement or state pension, 37% were living alone, and 41% had low education level for a median of 5.2 [inter-quartile range: 2.2-7.3) years. In adjusted regression models, a higher number of chronic conditions were associated with increased healthcare utilization. Both cardiovascular and non-cardiovascular hospital contacts were increased. Patients with low SEP had a higher number of chronic conditions, but SEP had limited influence on healthcare utilization. Patients living alone and those with low educational level had a trend towards a higher risk of all-cause mortality [adjusted hazard ratio (aHR): 1.17, 95% confidence interval (CI) 1.03-1.33, and aHR 1.09, 95% CI 0.96-1.24).

Conclusion

Multimorbidity increased the use of cross-sectional healthcare services, whereas low SEP had minor influence on the utilizations. Living alone and low educational level showed a trend towards a higher risk of mortality after CRT implantation.

High Incidence of Cardiovascular Disease in Patients With Oesophageal Cancer-A Registry-Based Cohort Study

BACKGROUND

The cardiovascular disease (CVD) burden among patients with oesophageal cancer (EC) treated with curative intent is unclear.

AIM

To determine CVD incidence and all-cause mortality in patients with EC.

METHOD

Danish national health registries were used to identify patients diagnosed with primary EC between 2008 and 2018. Each EC patient was matched with 10 individuals from the general population. The primary endpoint was a CVD hospital contact (CVD-HC), either admission or outpatient contact. Cox proportional hazard regression models were used to compare the risk of incident CVD-HCs between the cohorts.

RESULTS

The study included 1,525 patients with EC and 15,250 individuals from the general population. Patients with EC had a post-diagnosis one-year adjusted hazard ratio (HR) of CVD-HC of 6.1 (95% confidence intervals [CIs] 5.6-6.8) compared with the general population. During the next nine years, the risk of CVD-HC was comparable between the two cohorts, with an adjusted HR of 1.0 (95% CI 0.9-1.3). Patients with EC, and particularly those with prevalent CVD, had a high risk of atrial fibrillation, ischaemic heart disease, and venous thromboembolism within the first year after EC diagnosis. Prevalent CVD among patients with EC was not associated with higher mortality.

CONCLUSIONS

CVD morbidity was transiently increased in the first year following EC diagnosis compared with the general population. All-cause mortality risks were high but did not appear to be affected by prevalent CVD. The very high risk of CVD in patients with primary EC to be treated with curative intent calls for healthcare initiatives to advance preventive and post-treatment strategies.

Risk of cardiac conduction disorders, and pacemaker implantations among individuals tested for serum Borrelia burgdorferi antibodies, a nationwide, matched, population-based cohort study

OBJECTIVES

To investigate the short- and long-term risks of atrioventricular block and other cardiac conduction disorders associated with being tested for Borrelia burgdorferi (Bb) antibodies or Bb seropositivity as measures of confounding by indication and Bb infection, respectively.

METHODS

We performed a nationwide population-based matched cohort study (Denmark, 1993-2021). We included 52 200 Bb-seropositive individuals (stratified as only Bb-IgM-seropositive [n = 26 103], only Bb-IgG-seropositive [n = 18 698], and Bb-IgM-and-IgG-seropositive [n = 7399]) and two age- and sex-matched comparison cohorts: 104 400 Bb-seronegative individuals and 261 000 population controls. We investigated the risk associated with being tested for serum Bb antibodies and being Bb seropositive. Outcomes were atrioventricular block and other conduction disorders. We calculated short-term odds ratios (aOR) (within 1 month), and long-term hazard ratios (aHR) (after 1 month) adjusted for age, sex, diabetes, chronic heart failure, and kidney disease with 95% CI.

RESULTS

Compared with population controls, individuals tested for Bb antibodies had increased short- and long-term risks of atrioventricular block (aOR 47.9, 95% CI: 30.0-76.7, aHR 1.3, 95% CI:1.2-1.3), and other conduction disorders (aOR 18.2, 95% CI: 10.1-32.8, aHR 1.2, 95% CI: 1.1-1.4). Compared with Bb-seronegative individuals, only Bb-IgM-and-IgG-seropositive individuals had increased short-term risk of atrioventricular block (aOR: 2.1, 95% CI: 1.5-3.1).

DISCUSSION

The results suggest that Bb antibody testing is included in the diagnostic work-up of conduction disorders. Finally, that Bb seropositivity is not associated with other conduction disorders than atrioventricular block or with increased long-term risk of conduction disorders.

The association of postoperative morbidity and age on 5-year survival after colorectal surgery in the elderly population: a nationwide cohort study

AIM

This study aimed to evaluate the association of age and postoperative morbidity on 5-year overall survival (OS) after elective surgery for colorectal cancer.

METHOD

Patients undergoing elective, curatively intended surgery for colorectal cancer Union for International Cancer Control Stages I-III between January 2014 and December 2019 were selected from four Danish nationwide healthcare databases. Patients were divided into four groups: group I 65-69 years old; group II 70-74 years old; group III 75-79 years old; and group IV ≥80 years old. Propensity score matching was used to reduce potential confounding bias. The primary outcome was the association of age and postoperative morbidity with 5-year OS. The secondary outcome was conditional survival, given that the patient had already survived the first 90 days after surgery.

RESULTS

After propensity score matching with a 1:1 ratio, group II contained 2221 patients; group III 952 patients; and group IV 320 patients. There was no significant difference in 5-year OS between group I (reference) and groups II and III (P = 0.4 and P = 0.9, respectively). Patients with severe postoperative complications within 30 days after surgery had a significantly decreased OS (P < 0.01); however, when patients who died within the first 90 days were excluded from the analysis, the differences in 5-year OS were less pronounced across all age groups.

CONCLUSION

Postoperative morbidity, and not patient age, was associated with a lower 5-year OS. Long-term survival for patients who experience a complication is similar to patients who did not have a complication when conditioning on 90 days of survival.

Neonatal outcomes in women with Multiple Sclerosis - Influence of disease activity: A Danish nationwide cohort study

BACKGROUND

Maternal Multiple Sclerosis (MS) has been associated with an increased risk of adverse birth outcomes. We hypothesized that active disease during conception and pregnancy plays an important role in this context, which this study aims to address.

METHODS

We used the Danish registers to conduct a nationwide cohort study. Information on maternal disease activity during pregnancy was retrieved using proxies from the linked registers (hospitalization, magnetic resonance imaging of the brain, and use of systemic corticosteroids during pregnancy). Neonates, exposed in utero to maternal disease activity constituted the exposed cohort and the unexposed cohort constituted neonates without in utero exposure to maternal disease activity. The examined outcomes were preterm birth, small for gestational age, low 5-minute Apgar score, and major congenital anomalies. In logistic regression models we estimated the odds ratios (OR) with adjustment for confounders such as maternal age, comorbidities, parity, smoking, calendar year of birth, and disease-modifying treatment.

RESULTS

Among the study population of 2492 children of mothers with MS we identified 273 (11 %) neonates exposed to maternal disease activity during pregnancy, and 2219 (89 %) neonates without exposure to disease activity. The adjusted odds ratios (aOR) for preterm birth, small for gestational age, low 5-minute Apgar score, and major congenital anomalies among children born to women with disease activity during pregnancy were 0.92 (95 % confidence interval (95 % CI) 0.53-1.60), aOR 1.19 (95 % CI 0.62-2.26), aOR 2.57 (95 % CI 0.93-7.15) and aOR 0.93 (95 % CI 0.48-1.83), respectively.

CONCLUSIONS

Women with MS having disease activity during pregnancy did not have a statistically significantly increased risk of adverse neonatal outcomes compared to women with MS without disease activity, which is overall reassuring results. We believe, that this will be useful knowledge for patients and clinicians in planning a pregnancy and preparing a birth plan.

Comparative epidemiology of bacteraemia in two ageing populations: Singapore and Denmark

Burden of bacteraemia is rising due to increased average life expectancy in developed countries. This study aimed to compare the epidemiology and outcomes of bacteraemia in two similarly ageing populations with different ethnicities in Singapore and Denmark. Historical cohorts from the second largest acute-care hospital in Singapore and in the hospitals of two Danish regions included patients aged 15 and above who were admitted from 1 January 2006 to 31 December 2016 with at least 1 day of hospital stay and a pathogenic organism identified. Among 13 144 and 39 073 bacteraemia patients from Singapore and Denmark, similar 30-day mortality rates (16.5%; 20.3%), length of hospital stay (median 14 (IQR: 9-28) days; 11 (6-21)), and admission rate to ICU (15.5%; 15.6%) were observed, respectively. Escherichia coli, Klebsiella pneumoniae, and Staphylococcus aureus ranked among the top four in both countries. However, Singaporeans had a higher proportion of patients with diabetes (46.8%) and renal disease (29.5%) than the Danes (28.0% and 13.7%, respectively), whilst the Danes had a higher proportion of patients with chronic pulmonary disease (18.0%) and malignancy (35.3%) than Singaporeans (9.7% and 16.2%, respectively). Our study showed that top four causative organisms and clinical outcomes were similar between the two cohorts despite pre-existing comorbidities differed.

Semaglutide (Ozempic®) Use in Denmark 2018 Through 2023 ‒ User Trends and off-Label Prescribing for Weight Loss

Purpose

A surge in the use of semaglutide injection (Ozempic®) approved to treat type 2 diabetes (T2D) has led to a global supply shortage. We investigated contemporary user rates and clinical characteristics of semaglutide (Ozempic®) users in Denmark, and the extent of "off-label" prescribing for weight loss.

Patients and Methods

Nationwide population-based cross-sectional study based on linked health registries January 2018 through December 2023. All adults who received a first prescription of semaglutide once weekly (Ozempic®) were included. We examined quarterly rates of new users and total user prevalences, using other glucagon-like peptide-1 receptor agonists and weight loss medications as comparison. We also investigated user characteristics including T2D, glucose control, comedications, and cardiorenal disease.

Results

The new user rate of semaglutide (Ozempic®) remained stable at approximately 4 per 1000 adult person-years between 2019 and 2021 and then accelerated, peaking at 10 per 1000 in the first quarter of 2023 after which it declined sharply. User prevalence increased to 91,626 users in Denmark in 2023. The proportion of semaglutide (Ozempic®) new users who had a record of T2D declined from 99% in 2018 to only 67% in 2022, increasing again to 87% in 2023. Among people with T2D who initiated semaglutide (Ozempic®) in 2023, 52% received antidiabetic polytherapy before initiation, 39% monotherapy, and 8% no antidiabetic therapy. Most T2D initiators had suboptimal glucose control, with 83% having an HbA1c ≥48 mmol/mol and 68% ≥53 mmol/mol despite use of antidiabetic medication, and 29% had established atherosclerotic cardiovascular disease or kidney disease.

Conclusion

The use of semaglutide (Ozempic®) in Denmark has increased dramatically. Although not approved for weight loss without T2D, one-third of new users in 2022 did not have T2D. Conversely, most initiators with T2D had a clear medical indication for treatment intensification, and "off-label" use can only explain a minor part of the supply shortage.

Social characteristics and social benefit use among premenopausal breast cancer survivors in Denmark: a population-based cohort study

PURPOSE

In 2020, one million women aged < 55 years were diagnosed with breast cancer globally. The impact of breast cancer and its treatments on these women's ability to work and need for social benefits may differ by social characteristics. We evaluated social benefit use following breast cancer by education and cohabitation.

METHODS

We conducted a nationwide population-based cohort study, including women aged 18-55 years diagnosed with stage I-III breast cancer in Denmark during 2002-2011. Statistics Denmark provided information on cohabitation, education, and social benefit use from 1 year pre-diagnosis to 10 years post-diagnosis. We calculated weekly proportions of self-support, unemployment, disability pension, flexi jobs, and sick leave according to education and cohabitation.

RESULTS

Of 5345 women, 81.8% were self-supporting, 4.5% received disability pensions, 1.6% had flexi jobs, 3.6% were on sick leave, and 5.5% were unemployed 1 year pre-diagnosis. Ten years post-diagnosis, the proportions were 69.0%, 13.0%, 10.5%, 3.4%, and 2.0% of 3663 survivors. Disability pensions and flexi jobs increased from 12.1 to 26.4% and 2.8 to 13.5% in women with short education, from 4.1 to 12.8% and 1.8 to 12.2% in women with medium education, and from 0.8 to 6.0% and 0.9 to 6.9% in longer educated. Disability pensions increased more in women living alone (7.8 to 19.9%), than in cohabiting women (3.6 to 11.3%).

CONCLUSIONS

Use of social benefits reflecting lost ability to work was highest in less educated women and in women living alone.

IMPLICATIONS FOR CANCER SURVIVORS

Awareness of these groups is crucial when tailoring efforts to support work participation in cancer survivors.

Increased cancer incidence among patients with hidradenitis suppurativa - a Danish nationwide register study 1977-2017

BACKGROUND

The chronic, inflammatory skin disease hidradenitis suppurativa (HS) (prevalence: 0.5%-1%, diagnostic delay: 7-10 years) primarily arises in younger adults and frequently coincides with autoimmune comorbidities and unhealthy life-styles (smoking and obesity). These factors are known to increase cancer risk, but despite this, information on cancer occurrence among HS patients is scarce.

MATERIALS AND METHODS

A nationwide retrospective register-based study assessing relative risk of cancer - overall and by anatomical site - following HS diagnosis expressed as standardized incidence ratios (SIRs), which is ratios between observed cases among all Danes diagnosed with HS since 1977 and expected cases based on cancer incidence rates of the entire Danish population during the same period.

RESULTS

Participants consisted of a cohort of 13,919 Danes with HS, who during an average of 14.2 years of follow-up developed a total of 1,193 incident cancers, corresponding to a 40% increased risk (SIR = 1.4, 95% CI: 1.3 to 1.4, p < 0.001). Increased risks were observed for cancers of the respiratory system, oral cavity and pharynx, digestive organs and peritoneum, urinary tract, and the lymphatic tissues.

INTERPRETATION

These findings underline an unmet need for health monitoring, lifestyle interventions and cancer screening if and when relevant.

Acute patients discharged without an established diagnosis: risk of mortality and readmission of nonspecific diagnoses compared to disease-specific diagnoses

BACKGROUND

Nonspecific discharge diagnoses after acute hospital courses represent patients discharged without an established cause of their complaints. These patients should have a low risk of adverse outcomes as serious conditions should have been ruled out. We aimed to investigate the mortality and readmissions following nonspecific discharge diagnoses compared to disease-specific diagnoses and assessed different nonspecific subgroups.

METHODS

Register-based cohort study including hospital courses beginning in emergency departments across 3 regions of Denmark during March 2019-February 2020. We identified nonspecific diagnoses from the R- and Z03-chapter in the ICD-10 classification and excluded injuries, among others-remaining diagnoses were considered disease-specific. Outcomes were 30-day mortality and readmission, the groups were compared by Cox regression hazard ratios (HR), unadjusted and adjusted for socioeconomics, comorbidity, administrative information and laboratory results. We stratified into short (3-<12 h) or lengthier (12-168 h) hospital courses.

RESULTS

We included 192,185 hospital courses where nonspecific discharge diagnoses accounted for 50.7% of short and 25.9% of lengthier discharges. The cumulative risk of mortality for nonspecific vs. disease-specific discharge diagnoses was 0.6% (0.6-0.7%) vs. 0.8% (0.7-0.9%) after short and 1.6% (1.5-1.7%) vs. 2.6% (2.5-2.7%) after lengthier courses with adjusted HRs of 0.97 (0.83-1.13) and 0.94 (0.85-1.05), respectively. The cumulative risk of readmission for nonspecific vs. disease-specific discharge diagnoses was 7.3% (7.1-7.5%) vs. 8.4% (8.2-8.6%) after short and 11.1% (10.8-11.5%) vs. 13.7% (13.4-13.9%) after lengthier courses with adjusted HRs of 0.94 (0.90-0.98) and 0.95 (0.91-0.99), respectively. We identified 50 clinical subgroups of nonspecific diagnoses, of which Abdominal pain (n = 12,462; 17.1%) and Chest pain (n = 9,599; 13.1%) were the most frequent. The subgroups described differences in characteristics with mean age 41.9 to 80.8 years and mean length of stay 7.1 to 59.5 h, and outcomes with < 0.2-8.1% risk of 30-day mortality and 3.5-22.6% risk of 30-day readmission.

CONCLUSIONS

In unadjusted analyses, nonspecific diagnoses had a lower risk of mortality and readmission than disease-specific diagnoses but had a similar risk after adjustments. We identified 509 clinical subgroups of nonspecific diagnoses with vastly different characteristics and prognosis.

Employment Status Following Heart Transplantation: Data From the Danish Nationwide Social Service Payment Register During 20 years

Most studies on vocational rehabilitation after heart transplantation (HTX) are based on self-reported data. Danish registries include weekly longitudinal information on all public transfer payments. We intended to describe 20-year trends in employment status for the Danish heart-transplant recipients, and examine the influence of multimorbidity and socioeconomic position (SEP). Linking registry and Scandiatransplant data (1994-2018), we conducted a study in recipients of working age (19-63 years). The cohort contained 492 recipients (79% males) and the median (IQR) age was 52 years (43-57 years). Five years after HTX, 30% of the survived recipients participated on the labor market; 9% were in a flexible job with reduced health-related working capacity. Moreover, 60% were retired and 10% eligible for labor market participation were unemployed. Recipients with multimorbidity had a higher age and a lower prevalence of employment. Five years after HTX, characteristics of recipients with labor market participation were: living alone (27%) versus cohabitation (73%); low (36%) versus medium-high (64%) educational level; low (13%) or medium-high (87%) income group. Heart-transplant recipients with multimorbidity have a higher age and a lower prevalence of employment. Socioeconomically disadvantaged recipients had a lower prevalence of labor market participation, despite being younger compared with the socioeconomically advantaged.

Predictors and long-term patterns of medication adherence to glaucoma treatment in Denmark-an observational registry study of 30 100 Danish patients with glaucoma

BACKGROUND

Self-treatment with glaucoma medication (eye drops) has been associated with adherence challenges. Poor adherence results in worse outcomes in terms of visual field loss.

OBJECTIVE

To investigate patterns in medication adherence among Danish patients with glaucoma in relation to selected predictors of adherence, long-term adherence patterns, and long-term societal economic consequences of poor adherence.

METHODS AND ANALYSIS

This register-based study included 30 100 glaucoma patients followed for 10 years between 2000 and 2018. Glaucoma was identified from the Danish national registers by diagnosis of Open Angle Glaucoma and/or by redeemed prescriptions of glaucoma medication. Logistic regression models were applied to estimate patient characteristics related to medical adherence. Diagnosis-related group fees were applied to estimate healthcare costs.

RESULTS

High adherence in the first year(s) of treatment was less likely among men (ORfirst year: 0.78, 95% CI: 0.75 to 0.82), younger individuals and among those with a positive Charlson Comorbidity Index (CCI) score (ORfirst year/CCI≥3: 0.71, 95% CI: 0.63 to 0.80). Adherence in the first year and in the first two years was associated with adherence in the fifth (ORfirst year: 4.55, 95% CI: 4.30 to 4.82/ORfirst two years: 6.47, 95% CI: 6.10 to 6.86) as with adherence in the 10th year with slightly lower estimates. Being medical adherent was related to higher costs related to glaucoma medication after 5 and 10 years comparing with poor adherence, whereas poor adherence was associated with a marked increase in long-term costs for hospital contacts.

CONCLUSION

Increasing age, female sex and low comorbidity score are correlated with better adherence to glaucoma treatment. Adherence in the first years of treatment may be a good predictor for future adherence. In the long term, patients with poor adherence are overall more expensive to society in terms of hospital contacts.

Predicting the risks of kidney failure and death in adults with moderate to severe chronic kidney disease: multinational, longitudinal, population based, cohort study

OBJECTIVE

To train and test a super learner strategy for risk prediction of kidney failure and mortality in people with incident moderate to severe chronic kidney disease (stage G3b to G4).

DESIGN

Multinational, longitudinal, population based, cohort study.

SETTINGS

Linked population health data from Canada (training and temporal testing), and Denmark and Scotland (geographical testing).

PARTICIPANTS

People with newly recorded chronic kidney disease at stage G3b-G4, estimated glomerular filtration rate (eGFR) 15-44 mL/min/1.73 m2.

MODELLING

The super learner algorithm selected the best performing regression models or machine learning algorithms (learners) based on their ability to predict kidney failure and mortality with minimised cross-validated prediction error (Brier score, the lower the better). Prespecified learners included age, sex, eGFR, albuminuria, with or without diabetes, and cardiovascular disease. The index of prediction accuracy, a measure of calibration and discrimination calculated from the Brier score (the higher the better) was used to compare KDpredict with the benchmark, kidney failure risk equation, which does not account for the competing risk of death, and to evaluate the performance of KDpredict mortality models.

RESULTS

67 942 Canadians, 17 528 Danish, and 7740 Scottish residents with chronic kidney disease at stage G3b to G4 were included (median age 77-80 years; median eGFR 39 mL/min/1.73 m2). Median follow-up times were five to six years in all cohorts. Rates were 0.8-1.1 per 100 person years for kidney failure and 10-12 per 100 person years for death. KDpredict was more accurate than kidney failure risk equation in prediction of kidney failure risk: five year index of prediction accuracy 27.8% (95% confidence interval 25.2% to 30.6%) versus 18.1% (15.7% to 20.4%) in Denmark and 30.5% (27.8% to 33.5%) versus 14.2% (12.0% to 16.5%) in Scotland. Predictions from kidney failure risk equation and KDpredict differed substantially, potentially leading to diverging treatment decisions. An 80-year-old man with an eGFR of 30 mL/min/1.73 m2 and an albumin-to-creatinine ratio of 100 mg/g (11 mg/mmol) would receive a five year kidney failure risk prediction of 10% from kidney failure risk equation (above the current nephrology referral threshold of 5%). The same man would receive five year risk predictions of 2% for kidney failure and 57% for mortality from KDpredict. Individual risk predictions from KDpredict with four or six variables were accurate for both outcomes. The KDpredict models retrained using older data provided accurate predictions when tested in temporally distinct, more recent data.

CONCLUSIONS

KDpredict could be incorporated into electronic medical records or accessed online to accurately predict the risks of kidney failure and death in people with moderate to severe CKD. The KDpredict learning strategy is designed to be adapted to local needs and regularly revised over time to account for changes in the underlying health system and care processes.

Validity of Prescription-Defined and Hospital-Diagnosed Hypertension Compared with Self-Reported Hypertension in Denmark

Purpose

Hypertension is an important risk factor in cardio-epidemiological research, but data quality remains a concern. We validated different registry-based definitions of hypertension.

Patients and Methods

The cohort included all first-time responders of the Danish National Health Surveys (2010, 2013, or 2017). Prescription-defined hypertension was defined as ≥1 or ≥2 filled prescriptions of antihypertensive specific drugs in ≥1 or ≥2 different antihypertensive drug classes within 90, 180, or 365 days before survey response. Hospital-diagnosed hypertension was defined from hypertension diagnoses within five years before the survey response. Considering self-reported hypertension as the reference, we calculated the positive predictive value (PPV), the negative predictive value (NVP), the sensitivity, and the specificity of prescription-defined and hospital-diagnosed hypertension.

Results

Among 442,490 survey responders, 127,247 (29%) had self-reported hypertension. For prescription-defined hypertension with 365-day lookback, the PPV was highest for ≥2 prescriptions in ≥2 drug classes (94%) and lowest for ≥1 prescription in ≥1 drug class (85%). The NPV was highest for ≥1 prescription in ≥2 drug classes (94%) and lowest for ≥1 prescription in ≥2 drug classes (80%). The sensitivity was highest for ≥1 prescription in ≥1 drug class (79%) and lowest for ≥2 prescriptions in ≥2 drug classes (30%). The specificity was ≥94% for all algorithms. The PPV and specificity did not change noteworthy with length of lookback period, whereas the NPV and the sensitivity generally were higher for longer lookback. The algorithm ≥1 prescription in ≥2 drug classes with 365-day lookback was among the best balanced across all measures of validity (PPV=88%, NPV=94%, sensitivity=75%, specificity=96%). For hospital-diagnosed hypertension, the PPV was 90%, the NPV was 76%, the sensitivity was 22%, and the specificity was 99%.

Conclusion

Compared with self-reported hypertension, the algorithms for prescription-defined and hospital-diagnosed hypertension had high predictive values and specificity, but low sensitivity.

Excessive androgen exposure and risk of malignancies: A cohort study

BACKGROUND

A link between androgen use and the risk of cancers, especially prostate and breast cancer, has been suggested. The knowledge about a possible association is limited.

OBJECTIVE

The study aimed to investigate cancer incidence rates, particularly those related to prostate and breast cancer, in male androgen users and compare them to a control group.

METHODS

We included male androgen users identified through a nationwide anti-doping testing program in Danish fitness centers from 2006 to 2018. We paired each case with 50 male controls of the same age, selected randomly. The cohort was followed from baseline and until 2023. The outcome was the incidence of prostate cancer, breast cancer, or any cancer excluding non-melanoma skin cancer.

RESULTS

The study included 1,189 androgen users and 59,450 controls, with a mean age of 27 years at enrolment. During the follow-up period with a mean length of 11 years, 13 androgen users, and 612 controls were diagnosed with cancer. This resulted in an incidence rate ratio of 1.05 (95% CI: 0.55-1.81). None of the androgen users were diagnosed with prostate or breast cancer.

DISCUSSION AND CONCLUSION

Male androgen users did not face an increased short-term risk of cancer, neither overall nor related to prostate or breast cancer. Our study indicates that the absolute risk of malignancies in androgen users is comparable to that in the background population. However, we cannot exclude androgens as a cancer risk factor due to the limited sample size, relatively short follow-up period, and subject age.

Mortality Among Users of Anabolic Steroids

This cohort study investigates mortality and cause of death among a large cohort of androgenic anabolic steroid users, compared with a control group, in Denmark from January 3, 2006, to March 1, 2018.