Treatment patterns of antidepressants in children and adolescents in Scandinavia

The aim of this study was to examine variations in use of antidepressants among children and adolescents in the three Scandinavian countries (Sweden, Norway, and Denmark). We identified new users of antidepressants (5-17 years) during 2007-2018 and described the annual incidence rate, treatment duration, concomitant psychotropic drug use, and the clinical setting of the prescribing physician (in Sweden and Denmark). Incident use of antidepressants increased by a factor 1.9 in Sweden, 1.3 in Norway and decreased by a factor 0.6 in Denmark during the study period. In Sweden, 58% of antidepressant users were covered by a prescription 12 months after initiation compared to 40% in Norway and 49% in Denmark. Also, 34% of Swedish antidepressant users were in continuous treatment after 12 months compared to 26% in Norway and 31% in Denmark. Concomitant use of other psychotropics was more common in Sweden (57%) than in Norway (37%) and Denmark (27%). During 2007-2018, clinicians from psychiatry settings initiated 75% of antidepressant treatments in Sweden, while this was the case for 50% of prescriptions in Denmark, although the proportion increased over time. The number of new antidepressant users is high and still rising in Sweden compared to Norway and Denmark. Swedish antidepressant users are more likely to use other psychotropics and to be covered by an antidepressant prescription after one year. Most antidepressants in Sweden are prescribed by physicians within psychiatric settings suggesting that they are based on specialized psychiatric evaluation.

Attention-Deficit Hyperactivity Disorder (ADHD) Medication Use Trajectories Among Women in the Perinatal Period

BACKGROUND

An increasing number of women of reproductive age are treated with attention-deficit hyperactivity disorder (ADHD) medication; however, patterns of ADHD medication use for women in the perinatal period have not been well described.

OBJECTIVE

This study aimed to describe ADHD medication use patterns from 1 year before pregnancy to 1 year after delivery, and to describe sociodemographic characteristics and clinical features by medication trajectories.

METHODS

The population-based cohort study included pregnancies in Denmark between 1997 and 2020, from the Medical Birth Register, by women who filled at least one prescription for ADHD medication from 12 months before pregnancy until 12 months after delivery. We applied group-based trajectory modeling to classify women into subgroups based on the identification of heterogeneous ADHD medication treatment patterns, and described the characteristics associated with these groups.

RESULTS

Overall, we included 4717 pregnancies leading to liveborn singletons by 4052 mothers with a mean (standard deviation) age of 27.5 (5.6) years. We identified four treatment trajectories across pregnancy and the postpartum period: continuers (23.3%), discontinuers (41.8%), interrupters who ceased filling prescriptions during pregnancy but resumed postpartum (17.2%), and postpartum initiators (17.7%). Continuers were older at the time of conception, gave birth in more recent years, were more likely to smoke during pregnancy, and used other psychotropic medications during pregnancy. A large proportion of continuers used methylphenidate (89.1%) compared with the other groups (75.9-84.1%) and had switched ADHD medication type during the whole period (16.4% vs. 7.4-14.8%).

CONCLUSION

We found that approximately 60% of women discontinued or interrupted their ADHD medication around pregnancy, and those who continued differed in sociodemographic and clinical factors that may reflect more severe ADHD.

Validation of Obstetric Diagnosis and Procedure Codes in the Danish National Patient Registry in 2017

Purpose

This study aimed to systematically evaluate the validity of variables related to pregnancy, delivery, and key characteristics of the infant in the Danish National Patient Register using maternal medical records as the reference standard.

Patients and Methods

We reviewed medical records of 1264 women giving birth in the Region of Southern Denmark during 2017. We calculated positive (PPV) and negative (NPV) predictive values, sensitivity, and specificity to estimate the validity of 49 selected variables.

Results

The PPV was ≥0.90 on most pregnancy-related variables including parity, pre-gestational BMI, diabetes disorders, and previous cesarean section, while it was lower for hypertensive disorders, especially mild to moderate preeclampsia (0.49, 95% CI 0.32-0.66). Sensitivity ranged from 0.80 to 1.00 on all pregnancy-related variables, except hypertensive disorders (sensitivity 0.38-0.71, lowest for severe preeclampsia). On most delivery-related variables including obstetric surgical procedures (eg cesarean section and induction of labor), pharmacological pain-relief, and gestational age at delivery, PPV's ranged from 0.98 to 1.00 and the corresponding sensitivities from 0.87 to 1.00. Regarding infant-related variables, both the APGAR score registered five minutes after delivery and birthweight yielded a PPV of 1.00.

Conclusion

Obstetric coding in the Danish National Patient Register shows very high validity and completeness making it a valuable source for epidemiologic research.

Recognition and management of children and adolescents with conduct disorder: a real-world data study from four western countries

BACKGROUND

Conduct disorders (CD) are among the most frequent psychiatric disorders in children and adolescents, with an estimated worldwide prevalence in the community of 2-4%. Evidence-based psychological outpatient treatment leads to significant improvement in about two-thirds of cases. However, there seems to be considerable variation in rates of CD diagnoses and implementation of evidence-based interventions between nations. The aim of this study was to compare administrative prevalence and treatment patterns for CD in children and adolescents seen in health care systems across four Western countries (Denmark, Germany, Norway, and the USA).

METHODS

Cross-sectional observational study using healthcare data to identify children and adolescents (aged 0-19 years) with an ICD-10 code for CD within the calendar year 2018. Within each country's study population, the prevalence of CD, psychiatric comorbidity, psychopharmacological treatment, and psychiatric hospitalisation was calculated.

RESULTS

The prevalence of diagnosed CD differed 31-fold between countries: 0.1% (Denmark), 0.3% (Norway), 1.1% (USA) and 3.1% (Germany), with a male/female ratio of 2.0-2.5:1. The rate of psychiatric comorbidity ranged from 69.7 to 86.1%, with attention-deficit/hyperactivity disorder being most common. Between 4.0% (Germany) and 12.2% (USA) of youths with a CD diagnosis were prescribed antipsychotic medication, and 1.2% (Norway) to 12.5% (Germany) underwent psychiatric hospitalisation.

CONCLUSION

Recognition and characteristics of youths diagnosed with CD varied greatly by country. In some countries, the administrative prevalence of diagnosed CD was markedly lower than the average estimated worldwide prevalence. This variation might reflect country-specific differences in CD prevalence, referral thresholds for mental health care, diagnostic tradition, and international variation in service organisation, CD recognition, and availability of treatment offers for youths with CD. The rather high rates of antipsychotic prescription and hospitalisation in some countries are remarkable, due to the lack of evidence for these therapeutic approaches. These findings stress the need of prioritising evidence-based treatment options in CD. Future research should focus on possible reasons for inter-country variation in recognition and management of CD, and also address possible differences in patient-level outcomes.

Melatonin use among children, adolescents, and young adults: a Danish nationwide drug utilization study

We aimed to provide a detailed description of the use of melatonin in Danish children, adolescents, and young adults during 2012-2019. We identified melatonin users 0-24 years of age (n = 43,652; median age 16 years) via the Danish nationwide health registers. Melatonin is a prescription drug in Denmark. The incidence of melatonin use increased from 2.4 to 3.9/1000 person-years during 2012 to 2019. Among 6,557 incident users in 2019, 53% filled only a single prescription within the first 6 months. Long-term use was most common among the younger age groups, with 17% of 5-9-year-olds and 14% of 10-13-year-olds being in continued treatment (no treatment breaks) 12 months after their first melatonin prescription. Disregarding treatment breaks, 3 in 10 were using melatonin 12 months after their first melatonin prescription and this proportion was also highest among 5-9-year-olds (63%) and 10-13-year-olds (51%). Psychopathology was common among melatonin users with 75% registered with either a psychiatric disorder diagnosis (54%), a filled prescription for another psychotropic (58%), or a contact to a private practice psychiatrist (15%) within ± 12 months of treatment initiation. General practitioners authorized melatonin prescriptions to almost half of all new users (48%), while psychiatric specialists authorized 37% of first prescriptions. In conclusion, the incidence of melatonin use increased in Denmark from 2012 to 2019. A substantial proportion of users had concurrent psychopathology most likely explaining their use of melatonin. Long-term melatonin use was more common among the youngest age groups, which should be a focus of interest due to limited safety data.

Use of opioids among pregnant women 1997-2016: A Danish drug utilization study

OBJECTIVE

Use of opioids in pregnancy is of concern yet little is known on opioid prescription patterns in Denmark. The aim of this drug utilization study was to describe prescription patterns for opioids during pregnancy in Denmark from 1997 to 2016.

STUDY DESIGN

Using the nationwide health care registers, we obtained information on all women with a registered pregnancy in the period 1 January 1997 to 31 December 2016. Opioids were grouped in four: opioids (N02A except codeines), opioid dependency medications (N07BC), cough medications (R05DA except codeines), and codeines (N02AJ06, N02AJ07, N02BA75, and R05DA04). We used logistic regression analyses to identify factors associated with opioid use in pregnancy and cumulative oral morphine equivalent (OMEQ) to estimate volume of use in pregnancy.

RESULTS

Prescription patterns were similar for women with live births, non-live births, and terminations. Total use of opioids among women with live born deliveries remained stable at 19.8 per 1000 pregnancies from 1997 to 2016. Codeine use declined from 2008 onwards, while use of other opioids increased from 2007 onwards. This was dominated by a threefold increase in tramadol use (2.0-7.6 per 1000 pregnancies with live births). Codeine was the most used opioid, followed by tramadol and codeine combined with paracetamol. The number of women, who used opioids before pregnancy and continued into their pregnancy, was reduced as the pregnancy progressed. The cumulative oral morphine equivalent during pregnancy was stable until 2007, after which, use prior to pregnancy and during the first two trimesters increased. The odds ratios for opioid use were higher in pregnancies of women of lower socioeconomic status or older age. For live births, odds ratios for opioid use in pregnancy were higher among women with obesity or smoking.

CONCLUSIONS

Overall use of opioids was stable from 2007 to 2016. This covers a decline in the use of codeine, but a 3-fold increase in tramadol. The number of pregnant women who continued use throughout pregnancy decreased, while OMEQ among persistent users increased. The real-world data suggest an unmet need of specific focus in local Danish Outpatient Clinics and Multidisciplinary Pain Centers both pre-conceptionally and during pregnancy.

The short-term and long-term adverse effects of melatonin treatment in children and adolescents: a systematic review and GRADE assessment

Background

Currently, melatonin is used to treat children and adolescents with insomnia without knowing the full extent of the short-term and long-term consequences. Our aim was to provide clinicians and guideline panels with a systematic assessment of serious-and non-serious adverse events seen in continuation of melatonin treatment and the impact on pubertal development and bone health following long-term administration in children and adolescents with chronic insomnia.

Methods

We searched PubMed, Embase, Cinahl and PsycINFO via Ovid, up to March 17, 2023, for studies on melatonin treatment among children and adolescents (aged 5-20 years) with chronic insomnia. The language was restricted to English, Danish, Norwegian, and Swedish. Outcomes were non-serious adverse events and serious adverse events assessed 2-4 weeks after initiating treatment and pubertal development and bone health, with no restriction on definition or time of measurement. Observational studies were included for the assessment of long-term outcomes, and serious and non-serious adverse events were assessed via randomised studies. The certainty of the evidence was assessed using Grades of Recommendation, Assessment, Development and Evaluation (GRADE). The protocol is registered with the Danish Health Authority.

Findings

We identified 22 randomised studies with 1350 patients reporting on serious-and non-serious adverse events and four observational studies with a total of 105 patients reporting on pubertal development. Melatonin was not associated with serious adverse events, yet the number of patients experiencing non-serious adverse events was increased (Relative risk 1.56, 95% CI 1.01-2.43, 17 studies, I² = 47%). Three studies reported little or no influence on pubertal development following 2-4 years of treatment, whereas one study registered a potential delay following longer treatment durations (>7 years). These findings need further evaluation due to several methodological limitations.

Interpretation

Children who use melatonin are likely to experience non-serious adverse events, yet the actual extent to which melatonin leads to non-serious adverse events and the long-term consequences remain uncertain. This major gap of knowledge on safety calls for caution against complacent use of melatonin in children and adolescents with chronic insomnia and for more research to inform clinicians and guideline panels on this key issue.

Funding

The Danish Health Authority. The Parker Institute, Bispebjerg and Frederiksberg Hospital, supported by the Oak Foundation.

Prenatal antidepressant exposure and emotional disorders until age 22: a danish register study

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are the most frequently prescribed antidepressants in pregnancy. Animal and some clinical studies have suggested potential increases in depression and anxiety following prenatal SSRI exposure, but the extent to which these are driven by the medication remains unclear. We used Danish population data to test associations between maternal SSRI use during pregnancy and children outcomes up to age 22.

METHODS

We prospectively followed 1,094,202 single-birth Danish children born 1997-2015. The primary exposure was ≥ 1 SSRI prescription filled during pregnancy; the primary outcome, first diagnosis of a depressive, anxiety, or adjustment disorder, or redeemed prescription for an antidepressant medication. We used propensity score weights to adjust potential confounders, and incorporated data from the Danish National Birth Cohort (1997-2003) to further quantify potential residual confounding by subclinical factors.

RESULTS

The final dataset included 15,651 exposed and 896,818 unexposed, children. After adjustments, SSRI-exposed had higher rates of the primary outcome than those of mothers who either did not use an SSRI (HR = 1.55 [95%CI:1.44,1.67] or discontinued the SSRI use ≥ 3 months prior to conception (HR = 1.23 [1.13,1.34]). Age of onset was earlier among exposed (9 [IQR:7-13] years) versus unexposed (12 [IQR:12-17] years) children (p < 0.01). Paternal SSRI use in the absence of maternal use during the index pregnancy (HR = 1.46 [1.35,1.58]) and maternal SSRI use only after pregnancy (HR = 1.42 [1.35,1.49]) were each also associated with these outcomes.

CONCLUSIONS

While SSRI exposure was associated with increased risk in the children, this risk may be driven at least partly by underlying severity of maternal illness or other confounding factors.

Prayer and meditation practices in the early COVID-19 pandemic: A nationwide survey among Danish pregnant women. The COVIDPregDK study

BACKGROUND

The emergence of the COVID-19 pandemic and the derived changes in maternity care have created stress and anxiety among pregnant women in different parts of the world. In times of stress and crisis, spirituality, including spiritual and religious practices, may increase.

OBJECTIVE

To describe if the COVID-19 pandemic influenced pregnant women's considerations and practises of existential meaning-making and to investigate such considerations and practices during the early pandemic in a large nationwide sample.

METHODS

We used survey data from a nationwide cross-sectional study sent to all registered pregnant women in Denmark during April and May 2020. We used questions from four core items on prayer and meditation practices.

RESULTS

A total of 30,995 women were invited, of whom 16,380 participated (53%). Among respondents, we found that 44% considered themselves believers, 29% confirmed a specific form of prayer, and 18% confirmed a specific form of meditation. In addition, most respondents (88%) reported that the COVID-19 pandemic had not influenced their responses.

CONCLUSION

In a nationwide Danish cohort of pregnant women, existential meaning-making considerations and practices were not changed due to the COVID-19 pandemic. Nearly one in two study participants described themselves as believers, and many practised prayer and/or meditation.

Prenatal and Infant Exposure to Acid-Suppressive Medications and Risk of Allergic Diseases in Children

Importance

Existing observational data have indicated positive associations of acid-suppressive medication (ASM) use in prenatal and early life with allergic diseases in children; however, no study to date has accounted for confounding by indication or within-familial factors.

Objective

To evaluate the association of prenatal or infant exposure to ASMs with risk of allergic diseases in children.

Design, Setting, and Participants

This nationwide, cohort study included data from South Korea's National Health Insurance Service mother-child-linked database from January 1, 2007, to December 31, 2020. Participants included mother-child pairs of neonates born from April 1, 2008, to December 31, 2019.

Exposures

Prenatal and infant exposure to ASMs (histamine 2 receptor antagonists [H2RAs] and proton pump inhibitors [PPIs]).

Main Outcomes and Measures

Composite and individual outcomes of allergic diseases (asthma, allergic rhinitis, atopic dermatitis, and food allergy) in children (followed up to 13 years of age) were assessed. The ASM-exposed individuals were compared with unexposed individuals in propensity score (PS)-matched and sibling-matched analyses to control for various potential confounders and within-familial factors. Hazard ratios (HRs) with 95% CIs were estimated using Cox proportional hazards regression models.

Results

The study included 4 149 257 mother-child pairs. Prenatal exposure analyses included 808 067 PS-matched pairs (763 755 received H2RAs, 36 529 received PPIs) among women with a mean (SD) age of 31.8 (4.2) years. The PS-matched HR was 1.01 (95% CI, 1.01-1.02) for allergic diseases overall (asthma: HR, 1.02 [95% CI, 1.01-1.03]; allergic rhinitis: HR, 1.02 [95% CI, 1.01-1.02]; atopic dermatitis: HR, 1.02 [95% CI, 1.01-1.02]; food allergy: HR, 1.03 [95% CI, 0.98-1.07]); in sibling-matched analyses, the HRs were similar to those of PS-matched analyses but were not significant (allergic diseases: HR, 1.01; 95% CI, 0.997-1.01). Infant exposure analyses included 84 263 PS-matched pairs (74 188 received H2RAs, 7496 received PPIs). The PS-matched HR was 1.06 (95% CI, 1.05-1.07) for allergic diseases overall (asthma: HR, 1.16 [95% CI, 1.14-1.18]; allergic rhinitis: HR, 1.02 [95% CI, 1.01-1.03]; atopic dermatitis: HR, 1.05 [95% CI, 1.02-1.08]; food allergy: HR, 1.28 [95% CI, 1.10-1.49]); asthma risk (HR, 1.13; 95% CI, 1.09-1.17) remained significantly higher among children exposed to ASMs during infancy in sibling-matched analyses. The findings were similar for H2RAs and PPIs analyzed separately and were robust across all sensitivity analyses.

Conclusions and Relevance

The findings of this cohort study suggest that there is no association between prenatal exposure to ASMs and allergic diseases in offspring. However, infant exposure to ASMs was associated with a higher risk of developing asthma, although the magnitude was more modest than previously reported. Clinicians should carefully weigh the benefits of prescribing ASMs to children, accompanied by subsequent close monitoring for any clinically relevant safety signals.

Utilization of antidepressants, anxiolytics, and hypnotics during the COVID-19 pandemic in Scandinavia

OBJECTIVE

To study patterns of antidepressant, anxiolytic, and hypnotic drug utilization in Denmark, Norway, and Sweden during the first year of the COVID-19 pandemic.

METHODS

The monthly observed number of prescription fills of antidepressants, benzodiazepines and benzodiazepine-related hypnotics (BZ), and other anxiolytics and hypnotics (OAH) per population in 2020 were compared with predicted numbers based on analysis of covariance of prescription fills during 2015-2019.

RESULTS

In March 2020, there was an increased number of prescription fills for antidepressants, anxiolytics, and hypnotics in youths and adults aged 20-59 years in Denmark, Norway, and Sweden. Antidepressant prescription fills increased between 13.5 % and 31.3 % at the end of 2020 in all age groups in Denmark and 17.4 % in youths in Norway. BZ drug prescription fills increased by 20.8 % at the end of 2020 in the 20-59 year age group in Denmark and decreased by 16.7 % in youths in Sweden. A general increase of prescription fills of OAH at the end of 2020 was observed in all countries (range 24.0-80.0 % in Denmark, 11.5-30.8 % in Norway, and 9.1-12.1 % in Sweden). Increases of prescription fills of OAH occurred earlier in Denmark.

LIMITATIONS

Aggregated data with lack of information on indications.

CONCLUSIONS

Peaks of utilization of antidepressants, anxiolytics, and hypnotics observed in March 2020 may reflect medication stock piling. Increased antidepressant drug utilization in Denmark and in Norwegian youths together with the general increase in OAH utilization in the Scandinavian countries in late 2020 may indicate an increase of symptoms of depression and anxiety, as well as disturbed sleep.

Psychotropic Medication Use and Psychiatric Disorders During the COVID-19 Pandemic Among Danish Children, Adolescents, and Young Adults

Importance

The direct and indirect implications of the COVID-19 pandemic have been associated with the mental health of children and adolescents, but it is uncertain whether these implications have been associated with changes in prescribing and diagnosis patterns.

Objective

To examine psychotropic medication use and rates of psychiatric disorders in Danish children, adolescents, and young adults during the COVID-19 pandemic.

Design, Setting, and Participants

This population-based, descriptive register-based cohort study included all Danish individuals aged 5 to 24 years from January 1, 2017, until June 30, 2022.

Main Outcomes and Measures

Rates of filled prescriptions of psychotropic medications, including antipsychotics, anxiolytics, hypnotics, sedatives, antidepressants, and psychostimulants, and all inpatient and outpatient contacts with mental and behavioral disorders. Rates of new (incident) and total (prevalent) psychotropic medication use and psychiatric diagnoses were estimated. Rate ratios (RRs) were assessed between observed and expected numbers of incident psychotropic medication use or psychiatric diagnoses from March 2020 to June 30, 2022, comparing observed numbers with expected numbers predicted from the modeled prepandemic trend.

Results

The study identified 108 840 (58 856 female individuals [54%]; median [IQR] age, 18 [14-22] years) incident psychotropic medication users. From March 2020 (first national lockdown) to June 2022, the rate of incident users of any psychotropic medication showed a relative increase of 18% (RR, 1.18; CI, 1.17-1.20) compared with expected numbers, which was primarily associated with an increase among those aged 12 to 17 years of 37% (RR, 1.37; 95% CI, 1.34-1.41). Similarly, there was an overall relative increase of incident psychiatric disorders of 5% (incidence rate, 1.05; CI, 1.04-1.07) (incident cases, 114 048 [58 708 female individuals (51%)]), which was associated with an increase in hyperkinetic disorders (RR, 1.13; CI, 1.09-1.18) and anxiety disorders (RR, 1.04; CI, 1.02-1.06). Prevalence patterns showed similar trends of an overall increase in psychotropic medication use and psychiatric disorders. One of 3 new users of an individual drug group had filled a prescription for a drug from another psychotropic medication group within the prior 6 months.

Conclusions and Relevance

The results of this cohort study suggest that Danish youths experienced an increase in rates of psychotropic treatment and psychiatric disorder diagnoses during the COVID-19 pandemic, which was most pronounced among those aged 12 to 17 years. The increase was observed for children and adolescents with and without a psychiatric history within the last 5 years.

Risk factors for and pregnancy outcomes after SARS-CoV-2 in pregnancy according to disease severity: A nationwide cohort study with validation of the SARS-CoV-2 diagnosis

INTRODUCTION

We identified risk factors and outcomes associated with SARS-CoV-2 infection in pregnancy in a universally tested population according to disease severity and validated information on SARS-CoV-2 during pregnancy in national health registers in Denmark.

MATERIAL AND METHODS

Cohort study using data from national registers and medical records including all pregnancies between March 1, 2020 and February 28, 2021. We compared women with a validated positive SARS-CoV-2 test during pregnancy with non-infected pregnant women. Risk factors and pregnancy outcomes were assessed by Poisson and Cox regression models and stratified according to disease severity defined by hospital admission status and admission reason (COVID-19 symptoms or other). Using medical record data on actual period of pregnancy, we calculated predictive values of the SARS-CoV-2 diagnosis in pregnancy in the registers.

RESULTS

SARS-CoV-2 infection was detected in 1819 (1.6%) of 111 185 pregnancies. Asthma was associated with infection (relative risk [RR] 1.63, 95% confidence interval [CI] 1.28-2.07). Risk factors for severe COVID-19 disease requiring hospital admission were high body mass index (median ratio 1.06, 95% CI 1.04-1.09), asthma (RR 7.47, 95% CI 3.51-15.90) and gestational age at the time of infection (gestational age 28-36 vs < 22: RR 3.53, 95% CI 1.75-7.10). SARS-CoV-2-infected women more frequently had hypertensive disorders in pregnancy (adjusted hazard ratio [aHR] 1.31, 95% CI 1.04-1.64), early pregnancy loss (aHR 1.37, 95% CI 1.00-1.88), preterm delivery before gestational age 28 (aHR 2.31, 95% CI 1.01-5.26), iatrogenically preterm delivery before gestational age 37 (aHR 1.49, 95% CI 1.01-2.19) and small-for-gestational age children (aHR 1.28, 95% CI 1.05-1.54). The associations were stronger among women admitted to hospital for any reason. The validity of the SARS-CoV-2 diagnosis in relation to pregnancy in the registers compared with medical records showed a negative predictive value of 99.9 (95% CI 99.9-100.0) and a positive predictive value of 82.1 (95% CI 80.4-83.7).

CONCLUSIONS

Women infected with SARS-CoV-2 during pregnancy were at increased risk of hypertensive disorders in pregnancy, early pregnancy loss, preterm delivery and having children small for gestational age. The validity of Danish national registers was acceptable for identification of SARS-CoV-2 infection during pregnancy.

Fetal death after the introduction of COVID-19 mitigation measures in Sweden, Denmark and Norway: a registry-based study

It remains unclear whether the rate of fetal death has changed during the COVID-19 pandemic. We assessed the impact of COVID-19 mitigation measures on fetal death in Sweden (449,347 births), Denmark (290,857 pregnancies) and Norway (261,057 pregnancies) using robust population-based registry data. We used Cox regression to assess the impact of the implementation of pandemic mitigation measures on March 12th, 2020, on miscarriage (fetal loss before gestational week 22) and stillbirth (fetal loss after gestational week 22). A total of 11% of 551,914 pregnancies in Denmark and Norway ended in miscarriage, while the proportion of stillbirths among 937,174 births across the three countries was 0.3%. There was no difference in the risk of fetal death during the year following pandemic mitigation measures. For miscarriage, the combined hazard ratio (HR) for Norway and Denmark was 1.01 (95% CI 0.98, 1.03), and for stillbirth, the combined HR for all three countries was 0.99 (95% CI 0.89, 1.09). We observed a slightly decreased risk of miscarriage during the first 4 months, with an HR of 0.94 (95% CI 0.90, 0.99) after lockdown. In conclusion, the risk of fetal death did not change after the implementation of COVID-19 pandemic mitigation measures in the three Scandinavian countries.

Use of hypnotic drugs among Scandinavian children, adolescents, and young adults

Introduction

Hypnotic drug use in children and adolescents is widely debated.

Objectives

To describe use of hypnotic drugs (melatonin, z-drugs and sedating antihistamines) among 5-24-year-old Scandinavians during 2012 to 2018.

Methods

Aggregate-level data from public data sources in Sweden, Norway and Denmark. We calculated annual prevalence (users/1000 inhabitants) stratified by sex, age group and country. Quantity of use (Defined Daily Dose (DDD)/user/day) was estimated for Norway and Denmark.

Results

Melatonin was most frequently used, with an increase from 2012 to 2018 in all countries. Sweden presented the highest rise (7 to 25/1,000) compared to Denmark (6 to 12/1,000) and Norway (10 to 20/1,000). The increase was strongest for females and 15-24-year-olds. Melatonin use was twice as common for males under age 15 years, and slightly more common for females thereafter. The annual prevalence of sedating antihistamine use doubled from 7 to 13/1,000 in Sweden, whereas it was more stable in Norway and Denmark, reaching 8/1,000 and 3/1,000, respectively. Z-drug use decreased in all countries, lowering to 4/1,000 in Sweden and Norway in 2018 and 2/1,000 in Denmark. The quantity of hypnotic use in Norway and Denmark was 1 DDD/user/day for melatonin, as compared to 0.1-0.3 for z-drugs and antihistamines.

Conclusions

There is an increasing use of melatonin and sedating antihistamines among Scandinavian children, adolescents and young adults. The increase is more pronounced in Sweden compared to Norway and Denmark. This Scandinavian discrepancy could reflect variation in frequency of sleep problems or national variation in clinical practice or health care access.

Disclosure

No significant relationships.

Development and Validation of a Nordic Multimorbidity Index Based on Hospital Diagnoses and Filled Prescriptions

Purpose

To develop the Nordic Multimorbidity Index (NMI), a multimorbidity measure specifically suited to the Nordic health and administrative registry data based on current diagnosis, treatment, and coding practices.

Methods

The NMI was developed to predict 5-year mortality in a population-based cohort of randomly sampled Danish residents aged ≥40 years (n = 425,087) followed from 2013 to 2018. Included predictors were selected from hospital diagnoses and filled drug prescriptions based on a combination of subject matter knowledge and a data-driven approach using backwards elimination. The performance of the NMI was assessed in a temporal validation cohort of Danish residents followed from 2007 to 2012 and in six cohorts of new users of selected drugs. The discriminative performance of the NMI, Charlson Comorbidity Index (CCI) and the Elixhauser Comorbidity Index (ECI) was assessed using the c-statistic from logistic regression models with 5-year mortality as dependent variable and the multimorbidity index score, age, and sex as independent variables.

Results

The NMI included 50 predictors. In the temporal validation cohort, the c-statistic of the NMI (0.887, 95% CI 0.883–0.890) exceeded that of the CCI (0.871, 95% CI 0.868–0.874) and ECI (0.866, 95% CI 0.863–0.870). In all new user cohorts, the NMI outperformed the other indices with c-statistics ranging from 0.781 (95% CI 0.779–0.784) to 0.838 (95% CI 0.834–0.842).

Conclusion

The NMI predicted 5-year mortality in a general Danish population and six cohorts of new users of selected drugs and was superior to the CCI and ECI. The NMI could be preferred over these indices to quantify the level of multimorbidity for, eg, descriptive purposes or confounding control. The NMI should be validated in other patient populations and other Nordic countries.

The COVIDPregDK Study: A national survey on pregnancy during the early COVID-19 pandemic in Denmark

AIM

We aimed to describe the aim, data collection and content from a survey completed among pregnant women during the first peak of the COVID-19 pandemic in Denmark.

METHODS

The declaration of the COVID-19 pandemic in early 2020 challenged pregnant women's mental well-being due to a concern for their unborn child and their need for healthcare services through pregnancy and birth. To explore how the COVID-19 pandemic and the intensified measures such as the lockdown of Denmark impacted pregnant women's well-being and mental health, we conducted a questionnaire survey in the spring of 2020 when the COVID-19 pandemic was at its first peak, and the consequences for pregnant women and the unborn child were very uncertain. All women residing in Denmark and registered with an ongoing pregnancy on 24 April 2020 were invited to participate. The questionnaire included background information, variables on COVID-19 symptoms and validated batteries of questions on loneliness, anxiety, stress, quality of life, meditation and prayers. Additional questions were included to examine concerns related to pregnancy and childbirth during the pandemic.

COHORT CHARACTERISTICS

Almost 18,000 women answered the questionnaire, which represents 60% of all invited women who experienced a national lockdown for the first time. Their median age was 30 years, and they were more likely to be multiparous.

CONCLUSIONS

Data from the COVIDPregDK Study will enable us to gain valuable knowledge on how the pandemic, the intensified measures from the health authorities and the national lockdown affected pregnant women's mental health and their concerns during the COVID-19 pandemic.

Concerns about transmission, changed services and place of birth in the early COVID-19 pandemic: a national survey among Danish pregnant women. The COVIDPregDK study

BACKGROUND

The outbreak of the COVID-19 pandemic caused great uncertainty about causes, treatment and mortality of the new virus. Constant updates of recommendations and restrictions from national authorities may have caused great concern for pregnant women. Reports suggested an increased number of pregnant women choosing to give birth at home, some even unassisted ('freebirth') due to concerns of transmission in hospital or reduction in birthplace options. During April and May 2020, we aimed to investigate i) the level of concern about coronavirus transmission in Danish pregnant women, ii) the level of concern related to changes in maternity services due to the pandemic, and iii) implications for choice of place of birth.

METHODS

We conducted a nationwide cross-sectional online survey study, inviting all registered pregnant women in Denmark (n = 30,009) in April and May 2020.

RESULTS

The response rate was 60% (n = 17,995). Concerns of transmission during pregnancy and birth were considerable; 63% worried about getting severely ill whilst pregnant, and 55% worried that virus would be transmitted to their child. Thirtyeight percent worried about contracting the virus at the hospital. The most predominant concern related to changes in maternity services during the pandemic was restrictions on partners' attendance at birth (81%). Especially nulliparous women were concerned about whether cancelled antenatal classes or fewer physical midwifery consultations would affect their ability to give birth or care for their child postpartum.. The proportion of women who considered a home birth was equivalent to pre-pandemic home birth rates in Denmark (3%). During the temporary discontinue of public home birth services, 18% of this group considered a home birth assisted by a private midwife (n = 125), and 6% considered a home birth with no midwifery assistance at all (n = 41).

CONCLUSION

Danish pregnant womens' concerns about virus transmission to the unborn child and worries about contracting the virus during hospital appointments were considerable during the early pandemic. Home birth rates may not be affected by the pandemic, but restrictions in home birth services may impose decisions to freebirth for a small proportion of the population.

Forecasting lung cancer incidence, mortality, and prevalence to year 2030

BACKGROUND

Lung cancer incidence and prevalence is increasing worldwide and there is a focus on prevention, early detection, and development of new treatments which will impact the epidemiological patterns of lung cancer. The clinical characteristics and the trends in incidence, mortality, and prevalence of lung cancer in Denmark from 2006 through 2015 are described and a model for predicting the future epidemiological profile of lung cancer through 2030 is introduced.

METHODS

The study population comprised all cases of lung cancer, registered in the Danish Cancer Registry, who were alive on January 1, 2006 or had a first-time ever diagnosis of lung cancer during 2006 through 2015. Information on morphology, stage of the disease, comorbidity and survival was obtained from other Danish health registers. Based on NORDCAN data and estimated patient mortality rates as well as prevalence proportions for the period 2006 through 2015, future case numbers of annual incidence, deaths, and resulting prevalence were projected.

RESULTS

A total of 44.291 patients were included in the study. A shift towards more patients diagnosed with lower stages and with adenocarcinoma was observed. The incidence increased and the patient mortality rate decreased significantly, with a doubling of the prevalence during the observation period. We project that the numbers of prevalent cases of lung cancer in Denmark most likely will increase from about 10,000 at the end of 2015 to about 23,000 at the end of 2030.

CONCLUSIONS

Our findings support that lung cancer is being diagnosed at an earlier stage, that incidence will stop increasing, that mortality will decrease further, and that the prevalence will continue to increase substantially. Projections of cancer incidence, mortality, and prevalence are important for planning health services and should be updated at regular intervals.

SARS-CoV-2 infection in pregnancy in Denmark-characteristics and outcomes after confirmed infection in pregnancy: A nationwide, prospective, population-based cohort study

Introduction

Assessing the risk factors for and consequences of infection with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) during pregnancy is essential to guide clinical care. Previous studies on SARS‐CoV‐2 infection in pregnancy have been among hospitalized patients, which may have exaggerated risk estimates of severe outcomes because all cases of SARS‐CoV‐2 infection in the pregnant population were not included. The objectives of this study were to identify risk factors for and outcomes after SARS‐CoV‐2 infection in pregnancy independent of severity of infection in a universally tested population, and to identify risk factors for and outcomes after severe infection requiring hospital admission.

Material and methods

This was a prospective population‐based cohort study in Denmark using data from the Danish National Patient Register and Danish Microbiology Database and prospectively registered data from medical records. We included all pregnancies between March 1 and October 31, 2020 and compared women with a positive SARS‐CoV‐2 test during pregnancy to non‐infected pregnant women. Cases of SARS‐CoV‐2 infection in pregnancy were both identified prospectively and through register linkage to ensure that all cases were identified and that cases were pregnant during infection. Main outcome measures were pregnancy, delivery, maternal, and neonatal outcomes. Severe infection was defined as hospital admission due to coronavirus disease 2019 (COVID‐19) symptoms.

Results

Among 82 682 pregnancies, 418 women had SARS‐CoV‐2 infection during pregnancy, corresponding to an incidence of 5.1 per 1000 pregnancies, 23 (5.5%) of which required hospital admission due to COVID‐19. Risk factors for infection were asthma (odds ratio [OR] 2.19, 95% CI 1.41–3.41) and being foreign born (OR 2.12, 95% CI 1.70–2.64). Risk factors for hospital admission due to COVID‐19 included obesity (OR 2.74, 95% CI 1.00–7.51), smoking (OR 4.69, 95% CI 1.58–13.90), infection after gestational age (GA) 22 weeks (GA 22–27 weeks: OR 3.77, 95% CI 1.16–12.29; GA 28–36 weeks: OR 4.76, 95% CI 1.60–14.12), and having asthma (OR 4.53, 95% CI 1.39–14.79). We found no difference in any obstetrical or neonatal outcomes.

Conclusions

Only 1 in 20 women with SARS‐CoV‐2 infection during pregnancy required admission to hospital due to COVID‐19. Risk factors for admission comprised obesity, smoking, asthma, and infection after GA 22 weeks. Severe adverse outcomes of SARS‐CoV‐2 infection in pregnancy were rare.

End-of-life anticancer treatment - a nationwide registry-based study of trends in the use of chemo-, endocrine, immune-, and targeted therapies

BACKGROUND

Anticancer treatments near the end of a patient's life should generally be avoided, as it leaves the patient with no significant anticancer effect but increases the risk of severe side effects. We described the pattern of all end-of-life anticancer treatment in a population of Danish cancer patients.

METHODS

Using the Danish national health registries, we identified all patients deceased due to cancer 2010-2015. Anticancer treatment registered in the last 30 days of life was categorized as end-of-life treatment. Predictors of such treatment were investigated using logistic regression models.

RESULTS

We identified 42,277 patients (median age 70 years) of whom 16% received end-of-life anticancer treatment. This proportion did not change during the study period (p = .09). Chemotherapy alone was the most frequent treatment, accounting for 78% of all end-of-life treatment in 2010, decreasing to 71% in 2015. In contrast, end-of-life use of immunotherapy, targeted therapy and endocrine therapy increased during the study period. Breast cancer as index cancer was associated with the highest frequency of end-of-life treatment (23%), followed by malignant melanoma (21%), and prostate cancer (18%). Factors associated with lower odds for end-of-life treatment were female sex, older age, high burden of comorbidity, and being diagnosed >6 months prior to death.

CONCLUSIONS

We found a stable overall rate at 16% of patients receiving anticancer treatment within one month prior to death in this nationwide sample of cancer deaths. Further research is needed to assess whether this level of end-of-life treatment is justified or reflects inappropriate use.

Use of hypnotic drugs among children, adolescents, and young adults in Scandinavia

BACKGROUND

Hypnotic use in children and adolescents is controversial.

OBJECTIVE

To describe the use of hypnotic drugs (melatonin, z-drugs, and sedating antihistamines) among 5- to 24-year-old Scandinavians during 2012 to 2018.

METHODS

Aggregate-level data were obtained from public data sources in Sweden, Norway, and Denmark. We calculated annual prevalence (users/1000 inhabitants) stratified by age group, sex, and country. Quantity of use (Defined Daily Dose (DDD)/user/day) was estimated for Norway and Denmark.

RESULTS

Melatonin was the most commonly used hypnotic, and its use increased markedly from 2012 to 2018, particularly among females and 15- to 24-year-old individuals. Sweden had the highest increase in use (6.5 to 25/1000) compared with Norway (10-20/1000) and Denmark (5.7-12/1000). The annual prevalence of sedating antihistamine use was also highest in Sweden, reaching 13/1000 in 2018 in comparison to 7.5/1000 in Norway and 2.5/1000 in Denmark. Z-drug use decreased in all countries toward 2018, dropping to 3.5/1000 in Sweden, 4.4/1000 in Norway, and 1.7/1000 in Denmark. The quantity of hypnotic use in Norway and Denmark was 0.8-1.0 DDD/user/day for melatonin in 2018, as compared to 0.1-0.3 for z-drugs and antihistamines.

CONCLUSION

The use of melatonin and sedating antihistamines increased among young Scandinavians during 2012-2018, and the increase was twice as high in Sweden compared with Norway and Denmark. In addition, Sweden had the highest use of sedating antihistamines. The Scandinavian variation of hypnotic use could reflect differences in frequency of sleep problems between populations or variation of healthcare access or clinical practice between countries.

Validation of the Fracture Risk Evaluation Model (FREM) in predicting major osteoporotic fractures and hip fractures using administrative health data

BACKGROUND

Prevention of osteoporotic fractures remains largely insufficient, and effective means to identify patients at high, short-term fracture risk are needed. The FREM tool is available for automated case finding of men and women aged 45 years or older at high imminent (1-year) risk of osteoporotic fractures, based on administrative health data with a 15-year look-back. The aim of this study was to validate the performance of FREM, and the effect of applying a shorter look-back period. We also evaluated FREM for 5-year fracture risk prediction.

METHODS

Using Danish national health registers we generated consecutive general population cohorts for the years 2014 through 2018. Within each year and across the full time period we estimated the individual fracture risk scores and determined the actual occurrence of major osteoporotic fractures (MOF) and hip fractures. Risk scores were calculated with 15- and 5-year look-back periods. The discriminative ability was evaluated by area under the receiver operating curve (AUC), and negative predictive value (NPV) and positive predictive value (PPV) were estimated applying a calculated risk cut-off of 2% for MOF and 0.3% for hip fractures.

RESULTS

Applying a 15-year look-back, AUC was around 0.75-0.76 for MOF and 0.84-0.87 for hip fractures in 2014, with minor decreases in the subsequent fracture cohorts (2015 to 2018). Applying a 5-year look-back generated similar results, with only marginally lower AUC. In the 5-year risk prediction setting, AUC-values were 0.70-0.72 for MOF and 0.81-0.84 for hip fractures. Generally, PPVs were low, while NPVs were very high.

CONCLUSION

FREM predicts the 1- and 5-year risk of MOF and hip fractures with acceptable vs excellent discriminative power, respectively, when applying both a 15- and a 5-year look-back. Hence, the FREM tool may be applied to improve identification of individuals at high imminent risk of fractures using administrative health data.

Maternal weight change from prepregnancy to 18 months postpartum and subsequent risk of hypertension and cardiovascular disease in Danish women: A cohort study

BACKGROUND

One-fourth of women experience substantially higher weight years after childbirth. We examined weight change from prepregnancy to 18 months postpartum according to subsequent maternal risk of hypertension and cardiovascular disease (CVD).

METHODS AND FINDINGS

We conducted a cohort study of 47,966 women with a live-born singleton within the Danish National Birth Cohort (DNBC; 1997-2002). Interviews during pregnancy and 6 and 18 months postpartum provided information on height, gestational weight gain (GWG), postpartum weights, and maternal characteristics. Information on pregnancy complications, incident hypertension, and CVD was obtained from the National Patient Register. Using Cox regression, we estimated adjusted hazard ratios (HRs; 95% confidence interval [CI]) for hypertension and CVD through 16 years of follow-up. During this period, 2,011 women were diagnosed at the hospital with hypertension and 1,321 with CVD. The women were on average 32.3 years old (range 18.0-49.2) at start of follow-up, 73% had a prepregnancy BMI <25, and 27% a prepregnancy BMI ≥25. Compared with a stable weight (±1 BMI unit), weight gains from prepregnancy to 18 months postpartum of >1-2 and >2 BMI units were associated with 25% (10%-42%), P = 0.001 and 31% (14%-52%), P < 0.001 higher risks of hypertension, respectively. These risks were similar whether weight gain presented postpartum weight retention or a new gain from 6 months to 18 months postpartum and whether GWG was below, within, or above the recommendations. For CVD, findings differed according to prepregnancy BMI. In women with normal-/underweight, weight gain >2 BMI units and weight loss >1 BMI unit were associated with 48% (17%-87%), P = 0.001 and 28% (6%-55%), P = 0.01 higher risks of CVD, respectively. Further, weight loss >1 BMI unit combined with a GWG below recommended was associated with a 70% (24%-135%), P = 0.001 higher risk of CVD. No such increased risks were observed among women with overweight/obesity (interaction by prepregnancy BMI, P = 0.01, 0.03, and 0.03, respectively). The limitations of this observational study include potential confounding by prepregnancy metabolic health and self-reported maternal weights, which may lead to some misclassification.

CONCLUSIONS

Postpartum weight retention/new gain in all mothers and postpartum weight loss in mothers with normal-/underweight may be associated with later adverse cardiovascular health.

Congenital Malformations in Denmark: Considerations for the Use of Danish Health Care Registries

BACKGROUND

Danish health registers are used widely to examine associations between specific risk factors and congenital malformations. Various overall prevalence rates of malformations have been reported in Denmark indicating differences in the underlying data sources or malformation definitions. We described trends in registration of malformations in Denmark 1997-2017 and identified potential caveats for the use of Danish health registries in epidemiological studies. We composed a Danish adaptation of EUROCATs definition of malformations.

METHODS

Using nationwide Danish health registries, we identified all recorded pregnancies and followed livebirths for up to 5 years. We described the different data sources, ways to identify malformations, the overall rate of malformations over time, and identified the 10 most common major malformations.

RESULTS

A total of 1,340,774 foetuses and infants from 1,313,281 pregnancies among 747,144 women from 1997 to 2017 were analysed. Using primary and secondary diagnoses from all available sources and restricting hip malformations to diagnoses after 6 weeks postpartum, we found that 65,411 (49/1000) foetuses or infants had at least one major malformation defined by our Danish translation of EUROCATs definition of malformations. The prevalence of major malformations increased over time from 39/1000 in 1997 to 53/1000 in 2017. The most common specific malformations were malformations of cardiac septa (Q21) and great arteries (Q25) with a peak of 10 and 6/1000 births in 2010 and 2009, respectively.

CONCLUSION

Malformations should be identified using primary and secondary diagnoses from the Birth register, the Patient register, and the Cause of Death register. To increase transparency and external validity, classification of major malformations should be based on the Danish adaptation of EUROCATs classification of malformations.

Reproductive life in women with celiac disease; a nationwide, population-based matched cohort study

STUDY QUESTION

How does celiac disease (CD) influence women's reproductive life, both prior to and after the diagnosis?

SUMMARY ANSWER

Prior to the diagnosis of CD, an increased risk of adverse pregnancy outcomes was seen, whereas after the diagnosis, no influence on reproductive outcomes was found.

WHAT IS KNOWN ALREADY

CD has been associated with several conditions influencing female reproduction and pregnancy outcomes including spontaneous abortion and stillbirth.

STUDY DESIGN, SIZE, DURATION

A nationwide matched cohort study following 6319 women diagnosed with CD and 63166 comparison women and identifying reproductive events between the ages of 15 and 50 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Through linkage of several Danish national health registers, we identified all women diagnosed with CD between 1977 and 2016. We identified an age- and sex-matched comparison cohort and obtained data on reproductive outcomes for both cohorts. Adjusted stratified Cox and logistic regression models were used to estimate differences in reproductive outcomes between women with and without CD.

MAIN RESULTS AND THE ROLE OF CHANCE

Comparing women with diagnosed CD with the non-CD women, the chance of pregnancy, live birth and risk of stillbirth, molar and ectopic pregnancy, spontaneous abortion and abortion due to foetal disease was the same. However, prior to being diagnosed, CD women had an excess risk of spontaneous abortion equal to 11 extra spontaneous abortions per 1000 pregnancies (adjusted odds ratio (OR) = 1.12, 95% CI: 1.03, 1.22) and 1.62 extra stillbirths per 1000 pregnancies (adjusted OR = 1.57, 95% CI: 1.05, 2.33) compared with the non-CD women. In the period 0-2 years prior to diagnosis fewer pregnancies occurred in the undiagnosed CD group, equal to 25 (95% CI: 20-31) fewer pregnancies per 1000 pregnancies compared to the non-CD group and in addition, fewer undiagnosed CD women initiated ART-treatment in this period, corresponding to 4.8 (95% CI: 0.9, 8.7) fewer per 1000 women compared to non-CD women.

LIMITATIONS, REASONS FOR CAUTION

Validity of the diagnoses in the registers was not confirmed, but reporting to the registers is mandatory for all hospitals in Denmark. Not all spontaneous abortions will come to attention and be registered, whereas live- and stillbirths, ectopic and molar pregnancies and abortion due to foetal disease are unlikely not to be registered. We adjusted for several confounding factors but residual confounding cannot be ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that undiagnosed CD can affect female reproduction and the focus should be on early detection of CD in risk groups.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the Health Research Fund of Central Denmark Region and The Hede Nielsens Foundation, Denmark. The authors report no conflicts of interest in this work.

Serum vitamin K1 associated to microangiopathy and/or macroangiopathy in individuals with and without diabetes

OBJECTIVE

Vitamin K has proposed beneficial effects on cardiovascular health. We investigated whether serum vitamin K₁ was associated with prevalence of microangiopathy and/or macroangiopathy.

RESEARCH DESIGN AND METHODS

Serum vitamin K was quantified in 3239 individuals with and 3808 without diabetes enrolled in Vejle Diabetes Biobank (2007-2010). Each individual was assessed for microangiography and macroangiopathy at enrollment based on registered diagnoses in the Danish National Patient Registry according to the International Classification of Disease 8 (1977-1993) and 10 (since 1994). Using multinomial logistic regression, relative risk ratios (RRRs) were calculated within each group of individuals with and without diabetes. RRRs were estimated for microangiopathic/macroangiopathic status compared with individuals without complications as a function of 1 nmol/L increments in K₁. Adjustment for potential confounders was also performed.

RESULTS

Vitamin K₁ (median) varied 0.86-0.95 nmol/L depending on diabetes, microangiopathic and macroangiopathic status. In individuals with diabetes, the crude RRR for only having microangiopathy was 1.05 (95% CI 0.98 to 1.12) and was found significant when adjusting 1.10 (95% CI 1.01 to 1.19). RRR for having only macroangiopathy was 0.89 (95% CI 0.77 to 1.03) and was again significant when adjusting 0.79 (95% CI 0.66 to 0.96). In individuals without diabetes, adjustments again led to similar estimates that was not significant. The adjusted RRR for having only macroangiopathy was 1.08 (95% CI 0.98 to 1.19).

CONCLUSIONS

Serum vitamin K₁ levels were associated with microangiopathic and macroangiopathic status in individuals with diabetes, but considered of no clinical relevance. The clinical value of other candidate markers for vitamin K status needs to be evaluated in future studies.

Trends in antidepressant use among children and adolescents: a Scandinavian drug utilization study

OBJECTIVE

To compare antidepressant utilization in individuals aged 5-19 years from the Scandinavian countries.

METHODS

A population-based drug utilization study using publicly available data of antidepressant use from Denmark, Norway, and Sweden.

RESULTS

In the study period from 2007 to 2017, the proportion of antidepressant users increased markedly in Sweden (9.3-18.0/1000) compared to Norway (5.1-7.6/1000) and Denmark (9.3-7.5/1000). In 2017, the cumulated defined daily doses (DDD) of selective serotonin reuptake inhibitors were 5611/1000 inhabitants in Sweden, 2709/1000 in Denmark, and 1848/1000 in Norway. The use of 'other antidepressants' (ATC code N06AX) also increased in Sweden with a higher DDD in 2017 (497/1000) compared to Denmark (225/1000) and Norway (170/1000). The use of tricyclic antidepressants was generally low in 2017 with DDDs ranging between 30-42 per 1000. The proportion of antidepressant users was highest among 15- to 19-year-old individuals. Girls were more likely to receive treatment than boys, and the treated female/male ratios per 1000 were similar in Sweden (2.39), Denmark (2.44), and Norway (2.63).

CONCLUSION

Even in highly comparable healthcare systems like the Scandinavian countries', variation in antidepressant use is considerable. Swedish children and adolescents have a markedly higher and still increasing use of antidepressants compared to Danish and Norwegian peers.

Spondyloarthritis and Outcomes in Pregnancy and Labor: A Nationwide Register-Based Cohort Study

OBJECTIVE

To describe the prevalence of spondyloarthritis (SpA) and subtypes diagnosed prior to delivery in a nationwide population of pregnant women, and to estimate how SpA was associated with adverse pregnancy-related outcomes.

METHODS

Using the Danish Medical Birth Register, we identified 1,199,610 singleton pregnancies (1997-2016). Information on SpA and related subtypes (ankylosing spondylitis, psoriatic arthritis, reactive arthritis, arthritis associated with inflammatory bowel diseases, and undifferentiated SpA) was derived from the Danish National Patient Registry. Odds ratios were calculated using logistic regression models. The analyses were performed with overall SpA as exposure and stratified by subtype.

RESULTS

The overall prevalence of SpA diagnosed prior to delivery was 0.31%, increasing from 0.1% in 1997 to 0.6% in 2016. Comparing women without SpA to women with SpA, the adjusted odds ratios were increased for moderately preterm birth (OR_adj 1.56 [95% confidence interval (95% CI) 1.33-1.83]), very preterm birth (OR_adj 1.47 [95% CI 1.04-2.08]), elective cesarean section (OR_adj 1.44 [95% CI 1.26-1.64]), emergency cesarean section (OR_adj 1.17 [95% CI 1.04-1.33]), and use of epidural (OR_adj 1.11 [95% CI 1.02-1.20]). The odds ratios for small for gestational age birth and preeclampsia were not increased for women with SpA compared to controls. Results were comparable for the subtypes of SpA.

CONCLUSION

Pregnancies in women with SpA were more often complicated by adverse pregnancy outcomes than pregnancies in women without SpA. Clinicians should be aware of this when advising women with SpA in their childbearing years. Future research should focus on investigating causal relations and possible interventions aimed at preventing these outcomes.

Ischemic Stroke and Systemic Embolism in Warfarin Users With Atrial Fibrillation or Heart Valve Replacement Exposed to Dicloxacillin or Flucloxacillin

The antibiotics dicloxacillin and flucloxacillin induce cytochrome P450-dependent metabolism of warfarin. We explored the influence of these drug-drug interactions on the clinical effectiveness of warfarin therapy due to atrial fibrillation or heart valve replacement. Using the population-based Danish registers, we performed a propensity-score matched cohort study including around 50,000 episodes of dicloxacillin/flucloxacillin matched to phenoxymethylpenicillin and to no antibiotic, respectively. We estimated hazard ratios (HRs) with 95% confidence intervals (CIs) by comparing 21-day (days 7-28) risks of ischemic stroke/systemic embolism (SE) following initiation of each exposure. When compared with phenoxymethylpenicillin, dicloxacillin/flucloxacillin was associated with an HR of ischemic stroke/SE of 2.09 (95% CI 1.51-2.90; strongest for dicloxacillin (HR 2.17; 95% CI 1.56-3.02)). Use of an untreated comparator strengthened the association (HR 2.84; 95% CI 1.97-4.09). Dicloxacillin should be used with caution in patients receiving warfarin. This may also apply to flucloxacillin; however, more data on the risks associated with flucloxacillin exposure during warfarin therapy are needed.

Life after the loss: protocol for a Danish longitudinal follow-up study unfolding life and grief after the death of a child during pregnancy from gestational week 14, during birth or in the first 4 weeks of life

INTRODUCTION

After the death of a child during pregnancy, birth or in the neonatal period, parents often experience feelings of guilt, disenfranchisement, feelings of betrayal by one's own body and envy of others. Such bereavement results in high rates of distress: psychologically, emotionally, physiologically and existentially. These data are collected using a national, longitudinal cohort to assess grief in mothers and their partners after the death of a child during pregnancy, birth or in the neonatal period. Our aim is to achieve a general description of grief, emotional health, and existential values after pregnancy or perinatal death in a Danish population.

METHODS AND ANALYSIS

The cohort comprises mothers and their partners in Denmark who lost a child during pregnancy from gestational week 14, during birth or in the neonatal period (4 weeks post partum). We began data collection in 2015 and plan to continue until 2024. The aim is to include 5000 participants by 2024, generating the largest cohort in the field to date. Parents are invited to participate at the time of hospital discharge or via the Patient Associations homepage. Data are collected using web-based questionnaires distributed at 1-2, 7 and 13 months after the loss. Sociodemographic and obstetric variables are collected. Validated psychometric measures covering attachment, continuing bonds, post-traumatic stress, prolonged grief, perinatal grief and existential values were chosen to reach our aim.

ETHICS AND DISSEMINATION

The study was approved by The Danish National Data Protection Agency (no. 18/15684, 7 October 2014). The results will be disseminated in peer-reviewed and professional journals as well as in layman magazines, lectures and radio broadcasts.

A New Fracture Risk Assessment Tool (FREM) Based on Public Health Registries

Some conditions are already known to be associated with an increased risk of osteoporotic fractures. Other conditions may also be significant indicators of increased risk. The aim of the current study was to identify conditions for inclusion in a fracture prediction model (fracture risk evaluation model [FREM]) for automated case finding of high-risk individuals of hip or major osteoporotic fractures (MOFs). We included the total population of Denmark aged 45+ years (N = 2,495,339). All hospital diagnoses from 1998 to 2012 were used as possible conditions; the primary outcome was MOFs during 2013. Our cohort was split randomly 50/50 into a development and a validation dataset for deriving and validating the predictive model. We applied backward selection on ICD-10 codes (International Classification of Diseases and Related Health Problems, 10th Revision) by logistic regression to develop an age-adjusted and sex-stratified model. The FREM for MOFs included 38 and 43 risk factors for women and men, respectively. Testing FREM for MOFs in the validation cohort showed good accuracy; it produced receiver-operating characteristic (ROC) curves with an area under the ROC curve (AUC) of 0.750 (95% CI, 0.741 to 0.795) and 0.752 (95% CI, 0.743 to 0.761) for women and men, respectively. The FREM for hip fractures included 32 risk factors for both genders and showed an even higher accuracy in the validation cohort as AUCs of 0.874 (95% CI, 0.869 to 0.879) and 0.851 (95% CI, 0.841 to 0.861) for women and men were found, respectively. We have developed and tested a prediction model (FREM) for identifying men and women at high risk of MOFs or hip fractures by using solely existing administrative data. The FREM could be employed either at the point of care integrated into electronic patient record systems to alert physicians or deployed centrally in a national case-finding strategy where patients at high fracture risk could be invited to a focused DXA program. © 2018 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).

Breastfeeding and later maternal risk of hypertension and cardiovascular disease - The role of overall and abdominal obesity

In this study, we examined how any, full, and partial breastfeeding durations were associated with maternal risk of hypertension and cardiovascular disease (CVD), and how prepregnancy body mass index (BMI) and waist circumference 7 years postpartum influenced these associations. A total of 63,260 women with live-born singleton infants in the Danish National Birth Cohort (1996-2002) were included. Interviews during pregnancy and 6 and 18 months postpartum provided information on prepregnancy weight, height, and the duration of full and partial breastfeeding. Waist circumference was self-reported 7 years postpartum. Cox regression models were used to estimate hazard ratios of incident hypertension and CVD, registered in the National Patient Register from either 18 months or 7 years postpartum through 15 years postpartum. Any breastfeeding ≥4 months was associated with 20-30% lower risks of hypertension and CVD compared to <4 months in both normal/underweight and overweight/obese women. At follow-up starting 7 years postpartum, similar risk reductions were observed after accounting for waist circumference adjusted for BMI. Partial breastfeeding >2 months compared to ≤2 months, following up to 6 months of full breastfeeding, was associated with 10-25% lower risk of hypertension and CVD. Compared with short breastfeeding duration, additional partial breastfeeding was as important as additional full breastfeeding in reducing risk of hypertension and CVD. Altogether, longer duration of breastfeeding was associated with lower maternal risk of hypertension and CVD irrespective of prepregnancy BMI and abdominal adiposity 7 years after delivery. Both full and partial breastfeeding contributed to an improved cardiovascular health in mothers.

Examining Nonparticipation in the Maternal Follow-up Within the Danish National Birth Cohort

A follow-up questionnaire on maternal health was distributed within the Danish National Birth Cohort (established in 1996-2002) 14 years after the index birth. Responses were obtained from 41,466 (53.2%) of 78,010 eligible mothers. To ensure the appropriate use of these data, the possibility of selection bias due to nonparticipation had to be evaluated. We estimated 4 selected exposure-outcome associations (prepregnancy weight-depression; exercise-degenerative musculoskeletal conditions; smoking-heart disease; and alcohol consumption-breast cancer). We adjusted for several factors associated with participation and applied inverse probability weighting. To estimate the degree of selection bias, we calculated relative odds ratios for the relationship between the baseline cohort and the subset participating in the Maternal Follow-up. Participating women were generally healthier, of higher social status, and older than the baseline cohort. However, selection bias in the chosen scenarios was limited; ratios of the odds ratios ranged from -14% to 5% after adjustment for age, parity, social status, and, if the variable was not the exposure variable, prepregnancy body mass index, exercise, smoking, and alcohol consumption. Applying inverse probability weighting did not further reduce bias. In conclusion, while participants differed somewhat from the baseline cohort, selection bias was limited after factors associated with participation status were accounted for.

Epidemiology of cutaneous lupus erythematosus and the associated risk of systemic lupus erythematosus: a nationwide cohort study in Denmark

Objectives The objectives of this paper are to describe the epidemiology of cutaneous lupus erythematosus (CLE) and its subtypes in Denmark, and to investigate the probability of receiving a subsequent diagnosis of systemic lupus erythematosus (SLE) and the related time course. Methods A nationwide registry-based cohort study was conducted in Denmark based on data from the Danish National Patient Registry from 1998 to 2013 using International Classification of Diseases, Revision 10. Results We identified 2380 patients with CLE. The annual incidence rate (IR) of CLE was 2.74/100,000 with a female:male ratio of 4:1. During 12,047 person-years of follow-up, 8% were diagnosed with SLE. The probability of receiving a subsequent diagnosis of SLE was 12.9% after 10 years taking death as a competing risk into consideration, and the probability was highest among women and patients diagnosed with subacute CLE. The median time until a diagnosis of SLE was 2.05 years. Conclusions This is the first nationwide study on CLE in Denmark. Although we found the annual IR of CLE and the risk of receiving an additional diagnosis of SLE to be lower than previously described, continued monitoring and thorough information for patients with CLE is important due to the inherent risk of SLE.

First child's impact on parental relationship: an existential perspective

Background

The first child’s birth is for most mothers a profound experience carrying the potential to change life orientations and values. However, little is known of how becoming a mother influences the existential dimensions of life within the parental relationship for example how motherhood may change how we view our partner and what we find important. The aim of this study was to explore how becoming a mother might change the parental relationship seen from the mother’s perspective with a specific focus on dimensions related to existential meaning-making.

Methods

In 2011, 499 Danish first time mothers answered a questionnaire, from which five core items related to changes in the partner relationship from the perspective of the mother, informed this study. The cohort consisted of mothers who gave birth before the 32nd week of gestation (n = 127) and mothers who gave birth at full term (n = 372). Item 1 focused on thoughts and conversations with her partner about the life change. Item 2 referred to the potential feeling of stronger ties to the partner. Item 3 related to the feeling of being connected to ‘something bigger than one self’ together with the partner. Item 4 focused on potential conflicts due to having a child, and item 5 referred to the experience of dreams. Possible answers ranged from ‘To a high degree’ to ‘Not at all’.

Results

Most respondents found birth of the first child to have forged stronger ties to their partner and have led to both thoughts and conversations about how life together as a couple changed. At the same time, some experienced more conflicts with their partner than before giving birth, however, the majority did actually not. More than half felt their relationship linked to ‘something bigger than themselves’ or had had dreams on being a family.

Conclusion

Findings suggest motherhood transition to be a significant transformer of partnership relation influencing also existential meaning-making. Having the potential to be of importance for the health and vitality of the mother, partner and child, it seems essential to scientifically and clinically address concerns related to existential meaning-making in partner relationship.

Association of Pre-Pregnancy Body Mass Index, Pregnancy-Related Weight Changes, and Parity With the Risk of Developing Degenerative Musculoskeletal Conditions

OBJECTIVE

To examine how pre-pregnancy body mass index (BMI), parity, and pregnancy-related weight changes are associated with long-term risk of degenerative musculoskeletal conditions.

METHODS

A total of 79,687 mothers with singleton births from the Danish National Birth Cohort were included. Information on height and weight prior to pregnancy and 6 months postpartum as well as gestational weight gain (GWG) was obtained from telephone interviews, while parity was derived from the Danish Medical Birth Registry. Diagnoses of musculoskeletal conditions, including osteoarthritis, disc disorders, low back pain, and soft tissue disorders, were obtained from the Danish National Patient Registry. Hazard ratios (HRs) were estimated using a Cox proportional hazards regression model.

RESULTS

The cumulative incidence of musculoskeletal conditions during a median follow-up of 12.4 years was 19.7%. The risk of musculoskeletal conditions increased with both increasing pre-pregnancy BMI and increasing parity. Compared to normal-weight first-time mothers, the highest risk was seen in obese women with >2 births (HR 1.61 [95% confidence interval 1.41-1.83]). GWG of 10-15 kg was associated with the lowest risk of musculoskeletal conditions. Compared to women with no change in weight from preconception to 6 months after childbirth (±1 BMI unit), increasing postpartum weight increased the risk of musculoskeletal conditions in normal-weight and overweight women.

CONCLUSION

Our findings indicate that high pre-pregnancy BMI increases the risk of degenerative musculoskeletal conditions. Low and high GWG, higher postpartum weight retention, and especially higher parity are associated with an increased risk. Prevention of being overweight before, during, and after pregnancy may reduce the risk of development of degenerative musculoskeletal conditions among mothers.

Depressive symptoms in women's midlife in relation to their body weight before, during and after childbearing years

OBJECTIVE

This study aimed to examine how weight and weight changes related to pregnancy were associated with depressive symptoms 11-16 years after childbirth.

METHOD

We followed 16,998 first-time mothers from the Danish National Birth Cohort up till 16 years after birth and estimated associations between depressive symptoms and pre-pregnancy body mass index (BMI) (kg m-2), weight changes in different time periods, and BMI-adjusted waist circumference 7 years after birth (WCBMI, cm). Depressive symptoms were estimated by the Center for Epidemiologic Studies Depression 10-item scale. Multiple logistic regression analyses were used to estimate odds ratios (OR) and 95% confidence intervals.

RESULTS

Compared with normal-weight, we found that underweight, overweight and obesity were associated with greater odds of depressive symptoms (1.29, 1.24 and 1.73, respectively). Compared with weight change ±1 BMI unit during the total follow-up period, greater odds for depressive symptoms were observed with weight loss (OR 1.14, 0.96-1.36) or gain of 2-2.99 kg m-2 (OR 1.11, 0.92-1.33) or gain of ≥3 kg m-2 (OR 1.68, 1.46-1.94). WCBMI > 2.2 cm was associated with greater odds of depressive symptoms (OR 1.16, 0.99-1.36) than waist circumference as predicted by BMI.

CONCLUSION

Low and high pre-pregnancy BMI, weight changes and WCBMI larger than predicted were associated with more depressive symptoms in midlife.

Mental disorders in motherhood according to prepregnancy BMI and pregnancy-related weight changes--A Danish cohort study

BACKGROUND

Previous studies have shown an association between prepregnancy BMI and postpartum depression, but little is known about this association beyond one year postpartum and the influence of postpartum weight retention (PPWR).

METHODS

We used data from 70355 mothers from the Danish National Birth Cohort to estimate the associations between maternal prepregnancy BMI and PPWR, respectively, and incident depression/anxiety disorders until six years postpartum. Outcome was depression or anxiety diagnosed clinically or filling a prescription for an antidepressant. Cox regression was used to estimate hazard ratios (HR) with 95% confidence intervals (CI). Follow-up started at the day of delivery. For the analysis regarding PPWR, follow-up started six months postpartum.

RESULTS

Underweight, overweight and obesity were associated with depression and/or anxiety disorders when compared to normal-weight, though the associations were attenuated after adjustments (HR 1.24 [95% CI 1.06-1.45], 1.05 [95% CI 0.96-1.15] and 1.07 [95% CI 0.95-1.21] for underweight, overweight and obese, respectively). Compared to mothers who had returned to their prepregnancy BMI, risk of depression/anxiety disorders was increased for mothers, who from prepregnancy to 6 months postpartum experienced either weight loss >1 BMI unit (HR 1.19 [95% CI 1.06-1.25]), weight gain of 2-3 BMI units (HR 1.23 [95% CI 1.08-1.40]), or weight gain of ≥3 BMI units (HR 1.21 [95% CI 1.05-1.40]).

LIMITATION

Causal direction and mechanisms behind the associations are largely unknown.

CONCLUSIONS

Low prepregnancy body weight and postpartum weight gain or loss are associated with occurrence of depression and anxiety disorders.

Maternal pre-pregnancy BMI and intelligence quotient (IQ) in 5-year-old children: a cohort based study

BACKGROUND

An association between maternal pre-pregnancy BMI and childhood intelligence quotient (IQ) has repeatedly been found but it is unknown if this association is causal or due to confounding caused by genetic or social factors.

METHODS

We used a cohort of 1,783 mothers and their 5-year-old children sampled from the Danish National Birth Cohort. The children participated between 2003 and 2008 in a neuropsychological assessment of cognitive ability including IQ tests taken by both the mother and the child. Linear regression analyses were used to estimate the associations between parental BMI and child IQ adjusted for a comprehensive set of potential confounders. Child IQ was assessed with the Wechsler Primary and Preschool Scales of Intelligence--Revised (WPPSI-R).

RESULTS

The crude association between maternal BMI and child IQ showed that BMI was adversely associated with child IQ with a reduction in IQ of -0.40 point for each one unit increase in BMI. This association was attenuated after adjustment for social factors and maternal IQ to a value of -0.27 (-0.50 to -0.03). After mutual adjustment for the father's BMI and all other factors except maternal IQ, the association between paternal BMI and child IQ yielded a regression coefficient of -0.26 (-0.59 to 0.07), which was comparable to that seen for maternal BMI (-0.20 (-0.44 to 0.04)).

CONCLUSION

Although maternal pre-pregnancy BMI was inversely associated with the IQ of her child, the similar association with paternal BMI suggests that it is not a specific pregnancy related adiposity effect.