Treatments for Chronic Kidney Disease: A Systematic Literature Review of Randomized Controlled Trials

Delaying disease progression and reducing the risk of mortality are key goals in the treatment of chronic kidney disease (CKD). New drug classes to augment renin-angiotensin-aldosterone system (RAAS) inhibitors as the standard of care have scarcely met their primary endpoints until recently. This systematic literature review explored treatments evaluated in patients with CKD since 1990 to understand what contemporary data add to the treatment landscape. Eighty-nine clinical trials were identified that had enrolled patients with estimated glomerular filtration rate 13.9-102.8 mL/min/1.73 m2 and urinary albumin-to-creatinine ratio (UACR) 29.9-2911.0 mg/g, with (75.5%) and without (20.6%) type 2 diabetes (T2D). Clinically objective outcomes of kidney failure and all-cause mortality (ACM) were reported in 32 and 64 trials, respectively. Significant reductions (P < 0.05) in the risk of kidney failure were observed in seven trials: five small trials published before 2008 had evaluated the RAAS inhibitors losartan, benazepril, or ramipril in patients with (n = 751) or without (n = 84-436) T2D; two larger trials (n = 2152-2202) published onwards of 2019 had evaluated the sodium-glucose co-transporter 2 (SGLT2) inhibitors canagliflozin (in patients with T2D and UACR > 300-5000 mg/g) and dapagliflozin (in patients with or without T2D and UACR 200-5000 mg/g) added to a background of RAAS inhibition. Significant reductions in ACM were observed with dapagliflozin in the DAPA-CKD trial. Contemporary data therefore suggest that augmenting RAAS inhibitors with new drug classes has the potential to improve clinical outcomes in a broad range of patients with CKD.

External validation of a model to predict women most at risk of postpartum venous thromboembolism: Maternity clot risk

INTRODUCTION

Venous thromboembolism (VTE) is the leading cause of direct maternal mortality in high-income countries. We previously developed a risk prediction score for postpartum venous thromboembolism (VTE) in women without a previous VTE. In this paper, we provide further external validation and assess its performance across various groups of postpartum women from England.

MATERIALS AND METHODS

Cohort study using primary and secondary care data covering England. We used data from QResearch comprising women with pregnancies ending in live birth or stillbirth recoded in Hospital Episodes Statistics between 2004 and 2015. Outcome was VTE in the 6 weeks postpartum. Our predictor variables included sociodemographic and lifestyle characteristics, pre-existing comorbidities, and pregnancy and delivery characteristics.

RESULTS

Among 535,583 women with 700,185 deliveries, 549 VTE events were recorded (absolute risk of 7.8 VTE events per 10,000 deliveries). When we compared predicted probabilities of VTE for each woman from the original model with actual VTE events, we obtained a C-statistic of 0.67 (95% CI 0.65 to 0.70). However, our model slightly over-predicted VTE risk for the higher risk women (calibration slope = 0.84; 95% CI 0.74 to 0.94). Performance was similar across groups defined by calendar time, socioeconomic status, age group and geographical area. The score performed comparably with the existing algorithm used by the UK Royal College of Obstetrician and Gynaecologists.

CONCLUSIONS

Our model enables flexibility in setting new treatment thresholds. Adopting it in clinical practice may help optimise use of low-molecular-weight heparin postpartum to maximise health gain by better targeting of high-risk groups.

Incidence of Uncommon Clinical Events in USA Patients with Dialysis-Dependent and Nondialysis-Dependent Chronic Kidney Disease: Analysis of Electronic Health Records from TriNetX

INTRODUCTION

Further understanding of adverse clinical events in patients with chronic kidney disease (CKD) is needed. This study aimed to describe characteristics of patients with nondialysis-dependent (NDD) and dialysis-dependent (DD) CKD and to assess incidence rates of uncommon adverse clinical events of interest in these patients.

METHODS

This retrospective study used electronic medical record data from USA CKD patients (≥18 years) with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 between January 1, 2010, and December 31, 2018, obtained from the USA-based TriNetX database. NDD-CKD and DD-CKD were diagnosed and staged from ≥2 consecutive eGFR readings, recorded ≥90 days apart. Dialysis was identified using procedure codes for renal replacement therapy. Outcomes assessed were select uncommon adverse clinical events, defined by International Classification of Disease, 9th and 10th Revision codes.

RESULTS

Incidence rates of adverse clinical events per 100 person-years (95% confidence interval) were generally higher in patients with DD-CKD versus NDD-CKD. Differences were particularly pronounced for hyperkalemia (26.9 [26.2-27.6] vs. 4.5 [4.5-4.6]), acidosis (15.1 [14.7-15.6] vs. 3.4 [3.4-3.4]), and sepsis (14.6 [14.2-15.1] vs. 3.3 [3.3-3.4]). Among DD-CKD patients, incidence rates of adverse events were particularly high during the first 3 months following dialysis initiation. Incidence of adverse clinical events generally increased with decreasing eGFR among patients with NDD-CKD and with hemoglobin <10 g/dL in both NDD- and DD-CKD patients.

CONCLUSIONS

Our results help establish baseline rates of uncommon adverse clinical events and provide additional evidence of increased morbidity for patients with DD-CKD versus NDD-CKD.

MO494INSIDE CKD: MODELLING THE ECONOMIC BURDEN OF CHRONIC KIDNEY DISEASE IN EUROPE USING PATIENT-LEVEL MICROSIMULATION

Background and Aims

Chronic kidney disease (CKD) is a debilitating and costly condition, affecting approximately 10% of people globally. Progression of CKD is associated with an increased incidence of adverse renal and cardiovascular outcomes, and premature mortality, as well as increased requirement for renal replacement therapies (RRTs), which are associated with significant healthcare costs and resource use. The trajectories of CKD prevalence, progression, outcomes and the related costs are therefore critical considerations for public health and policy planning. Using country-specific, patient-level microsimulation, Inside CKD aims to model the global clinical and economic burden of CKD from 2020 to 2025.

Method

We used the Inside CKD microsimulation to model the economic burden of CKD in Europe. A virtual general population was developed for each country using national survey data and relevant data from published literature. Data inputs included country demographics, the prevalence of CKD and RRT, comorbidities and complication rates, as well as associated healthcare costs. CKD stages were defined according to Kidney Disease Improving Global Outcomes (KDIGO) 2012 recommendations and patients were categorized according to estimated glomerular filtration rate and albuminuria status. RRT modelling was calibrated against historical trends from country-specific renal registries. Model validation and calibration were conducted following established methods for health economic modelling. Here, we report the initial results from the UK analysis, with further analyses currently underway for additional European countries.

Results

The UK analysis revealed that annual healthcare costs associated with CKD will increase linearly from £12.51B to £13.99B between 2020 and 2025. The largest absolute increase in cost was observed in CKD stage 3b (£0.75B); however, CKD stage 5 had the largest relative increase in cost with an approximately three-fold increase (£0.14B to £0.41B). By 2025, costs associated with CKD will increase across all age categories (18–34, 35–64 and 65+ years); the 35–64 age group had the largest absolute increase in costs with an increase of £1.14B (£2.02B to £3.16B). The largest relative increase in cost was observed in the 18–34 age category, with a three-fold increase in costs (£0.09B to £0.27B).

Conclusion

Initial results from Inside CKD demonstrate that CKD poses a significant economic burden over the next 5 years. CKD stages 3b and 5 were associated with the most pronounced cost increases, likely due to increased prevalence for stage 3b and greater treatment cost for stage 5. Notably, the largest increase in CKD costs was observed in the 35–64-year-old ‘working’ population. Further policy interventions aimed at early diagnosis and proactive management should be considered to slow disease progression, improve patient outcomes and reduce the economic burden associated with CKD.

MO518INSIDE CKD: MODELLING THE ECONOMIC BURDEN OF CHRONIC KIDNEY DISEASE IN THE AMERICAS AND THE ASIA-PACIFIC REGION USING PATIENT-LEVEL MICROSIMULATION

Background and Aims

Chronic kidney disease (CKD) is a debilitating and costly condition, with an estimated global prevalence of approximately 10%. Progression of CKD is associated with end-stage renal disease, cardiovascular events and premature mortality, as well as increased requirement for renal replacement therapies (RRTs), which are associated with significant healthcare costs and resource use. Furthermore, patients with CKD often have additional comorbidities, which are associated with CKD progression and increased costs. The trajectories of CKD prevalence, progression, outcomes and the related costs are therefore critical considerations for public health and policy planning. Using country-specific, patient-level microsimulation, Inside CKD aims to model the global clinical and economic burden of CKD from 2020 to 2025.

Method

We used the Inside CKD microsimulation to model the economic burden of CKD in the Americas and Asia-Pacific region. We developed a virtual general population for each country using national survey data and relevant data from published literature. Data inputs included country demographics, the prevalence of CKD and RRT, comorbidities and complication rates as well as associated healthcare costs. CKD stages were defined according to Kidney Disease Improving Global Outcomes (KDIGO) 2012 recommendations and patients were categorized according to estimated glomerular filtration rate and albuminuria status. We calibrated the RRT modelling against historical trends from country-specific renal registries. We conducted model validation and calibration using established methods for health economic modelling. Here, we report the results from the US and Canada analyses, with further analyses currently underway for additional countries in the Americas and Asia-Pacific region.

Results

Initial results for the US and Canada revealed that, between 2020 and 2025, annual healthcare costs associated with CKD will increase linearly from US$232.3B to US$376.2B in the US and from C$21.4B to C$34.1B in Canada (this figure does not include complication costs). In the US, the largest absolute increase in cost was observed in CKD stage 3a ($98.4B); however, CKD stage 4 had the largest relative increase in cost with an approximately three-fold increase (US$7.30B to US$23.3B). In Canada, the largest absolute increase in cost was observed in CKD stage 3a (C$5.84B); whereas CKD stage 5 had the largest relative increase in cost with an approximately five-fold increase (C$0.27B to C$1.41B). By 2025, costs associated with CKD will increase across all age categories (18–34, 35–64 and 65+ years) in both countries. In the US, the 35–64 age group had the largest absolute increase in costs with an increase of $74B (US$58.3B to US$132B). The largest relative increase in cost was observed in the 18–34 age category, with approximately a three-fold increase in costs (US$3.76B to US$10.2B). In Canada, the 65+ age group had the largest absolute increase in costs with an increase of C$7.9B (C$16.4B to C$24.3B). Both the 18–34 and 35–64 age categories had the largest relative increase in costs, with an approximately two-fold increase (C$0.25B to C$0.49B and C$4.77B to C$9.31B, respectively).

Conclusion

Initial results from Inside CKD demonstrate that CKD poses a significant economic burden over the next 5 years. CKD stage 3a was associated with the most pronounced cost increases in both the US and Canada, likely due to the increased prevalence of this stage. In the US, the largest increase in CKD costs was observed in the 35–64-year-old ‘working’ population, whereas the largest increase in Canada was observed in the 65 years old and over population. Further policy interventions aimed at early diagnosis and proactive management should be considered to slow disease progression, improve patient outcomes and reduce the economic burden associated with CKD.

MO486INSIDE CKD: MODELLING THE IMPACT OF IMPROVED SCREENING FOR CHRONIC KIDNEY DISEASE IN THE AMERICAS AND ASIA-PACIFIC REGION

Background and Aims

With an estimated global prevalence of 10%, chronic kidney disease (CKD) and its associated complications place a substantial strain on healthcare systems worldwide, which is compounded by the burden of undiagnosed CKD. Early CKD diagnosis followed by guideline-recommended interventions can improve patient outcomes and reduce associated healthcare-related costs, particularly by delaying or preventing the development of complications and progression to kidney failure. Urinary albumin-to-creatinine ratio (UACR) can be used to screen for CKD, but adherence to screening recommendations is suboptimal in routine care. Inside CKD aims to model the global clinical and economic burden of CKD using country-specific, patient-level microsimulation models. We used the Inside CKD microsimulation to model the potential clinical and economic impacts of routine measurement of UACR followed by appropriate intervention in patients aged 45 years and over in the US and Canada.

Method

The Inside CKD microsimulation model was used to model the clinical and economic impacts associated with measurement of UACR with subsequent appropriate intervention during routine primary care visits versus current practice in individuals aged 45 years and over. The model covers the period 2020–2025. In preliminary analyses, virtual populations representing the general populations of the US and Canada were constructed using published country-specific data, including demographics, prevalence of CKD and comorbidities (type 2 diabetes, uncontrolled hypertension and heart failure), incidence of complications (heart failure, myocardial infarction, stroke and acute kidney injury) and costs associated with CKD. The model also included parameters relating to the proportion of patients who visit a primary care physician at least once a year, the proportion of patients who agreed to UACR measurements, and the diagnostic sensitivity and specificity of UACR measurements. The modelling is being expanded to additional countries in the Americas and the Asia-Pacific region.

Results

Preliminary results from the US and Canada show that over the 2020–2025 period routine measurement of UACR during primary care visits followed by appropriate intervention could prevent progression to CKD stages 3b–5 in approximately 1.3M patients in the US and 160 000 in Canada, compared with current clinical practice, with linear increases in the cumulative numbers of prevented cases (Figure). Associated savings in healthcare costs in 2025 are projected to be approximately US$16B in the US and C$2.5B in Canada, corresponding to a reduction in cost for that year of 4.4% and 7.4%, respectively, compared with current clinical practice.

Conclusion

Preliminary results from the Inside CKD microsimulation model in the US and Canada show that routine measurement of UACR with subsequent intervention in primary care would prevent progression to CKD stages 3b–5 in a substantial number of patients compared with current screening practices, and could therefore decrease associated healthcare costs considerably. This analysis is being extended to further countries in the Americas and the Asia-Pacific region.

MO498INSIDE CKD: MODELLING THE CLINICAL AND ECONOMIC IMPACTS OF TARGETED URINARY ALBUMIN-TO-CREATININE RATIO SCREENING IN EUROPEAN COUNTRIES

Background and Aims

With an estimated global prevalence of 10% or more, chronic kidney disease (CKD) and its associated complications constitute a major challenge for healthcare systems worldwide, which is worsened by the burden of undiagnosed CKD. Early diagnosis of CKD followed by guideline-recommended interventions can improve patient outcomes, particularly by delaying or preventing progression to kidney failure. This may result in a reduction in the costs associated with managing CKD. Elevated albuminuria is a strong predictor of risk of complications and death in patients with CKD, and measurement of urinary albumin-to-creatinine ratio (UACR) is an important diagnostic and prognostic tool. However, adherence to screening recommendations is suboptimal in routine care. Inside CKD aims to model the global clinical and economic burden of CKD using country-specific, patient-level microsimulation models. We used the Inside CKD microsimulation to model the potential clinical and economic impacts of routine UACR measurement with appropriate intervention in primary care settings in UK patients aged 45 years and over. This analysis is being expanded to further European countries.

Method

We used the Inside CKD microsimulation to model the clinical and economic impacts of measuring UACR with subsequent appropriate intervention during routine primary care visits in all individuals aged 45 years and over, versus current practice (i.e. screening in patients with diabetes, hypertension or cardiovascular disease). The model covers the period 2020–2025. First, a virtual population representing the general population of the UK was constructed using data from the 2016 Health Survey for England, covering demographics, prevalence of CKD and comorbidities (type 2 diabetes, uncontrolled hypertension and heart failure) and incidence of complications (heart failure, myocardial infarction, stroke and acute kidney injury). The model also included parameters relating to the direct and indirect costs associated with CKD (e.g. cost of renal replacement therapy), the proportion of patients who visit a primary care physician at least once a year, the proportion of patients who agree to UACR measurements, and the diagnostic sensitivity and specificity of UACR measurements.

Results

Preliminary results from the UK show that over the 2020–2025 period, routinely measuring UACR in all patients aged 45 years and over during primary care visits could prevent progression to CKD stages 3b–5 in approximately 327 000 patients, compared with current clinical practice, with a linear increase in the cumulative number of prevented cases over the 5 years (Figure). Associated savings in costs related to the management of CKD and its complications are projected to be approximately £300M in 2025, corresponding to a 1.9% reduction from current clinical practice.

Conclusion

Preliminary results from this Inside CKD microsimulation model show that implementation of routine measurement of UACR in primary care settings in the UK could prevent a substantial number of patients progressing to CKD stages 3b–5 and has the potential to reduce the associated healthcare-related costs considerably. This analysis is being extended to other European countries.

Methods and rationale of the DISCOVER CKD global observational study

Background

Real-world data for patients with chronic kidney disease (CKD), specifically pertaining to clinical management, metabolic control, treatment patterns, quality of life (QoL) and dietary patterns, are limited. Understanding these gaps using real-world, routine care data will improve our understanding of the challenges and consequences faced by patients with CKD, and will facilitate the long-term goal of improving their management and prognosis.

Methods

DISCOVER CKD follows an enriched hybrid study design, with both retrospective and prospective patient cohorts, integrating primary and secondary data from patients with CKD from China, Italy, Japan, Sweden, the UK and the USA. Data will be prospectively captured over a 3-year period from >1000 patients with CKD who will be followed up for at least 1 year via electronic case report form entry during routine clinical visits and also via a mobile/tablet-based application, enabling the capture of patient-reported outcomes (PROs). In-depth interviews will be conducted in a subset of ∼100 patients. Separately, secondary data will be retrospectively captured from >2 000 000 patients with CKD, extracted from existing datasets and registries.

Results

The DISCOVER CKD program captures and will report on patient demographics, biomarker and laboratory measurements, medical histories, clinical outcomes, healthcare resource utilization, medications, dietary patterns, physical activity and PROs (including QoL and qualitative interviews).

Conclusions

The DISCOVER CKD program will provide contemporary real-world insight to inform clinical practice and improve our understanding of the epidemiology and clinical and economic burden of CKD, as well as determinants of clinical outcomes and PROs from a range of geographical regions in a real-world CKD setting.

Mortality among patients with polymyalgia rheumatica: A retrospective cohort study

OBJECTIVE

To determine whether a diagnosis of polymyalgia rheumatica (PMR) is associated with premature mortality.

METHODS

We extracted anonymised electronic medical records of patients over the age of 40 years, who were eligible for linkage with the Office for National Statistics (ONS) Death Registration dataset, from the Clinical Practice Research Datalink from 1990-2016. Patients with PMR were individually matched by age, sex and registered General Practice with up to 5 controls without PMR. The total number and proportion of deaths and mortality rates were calculated. The mortality rate ratio (MRR), with 95% confidence interval (CI), adjusted for age, sex, region, smoking status, body mass index (BMI), and alcohol consumption, was calculated using Poisson regression. The twenty most common causes of death were tabulated.

RESULTS

18,943 patients with PMR were matched to 87,801 controls. Mean (standard deviation) follow-up after date of diagnosis was 8.0 (4.4) years in patients with PMR, and 7.9 (4.6) in controls. PMR was not associated with an increase in the risk of death (adjusted MRR 1.00 [95% CI 0.97, 1.03]) compared to matched controls. Causes of death were broadly similar between patients with PMR and controls, although patients with PMR were slightly more likely to have a vascular cause of death recorded (24% vs 23%).

CONCLUSIONS

A diagnosis with PMR does not appear to increase the risk of premature death. Minor variations in cause of death were observed, but overall this study is reassuring for patients with PMR and clinicians.

Venous thromboembolism in patients with gout and the impact of hospital admission, disease duration and urate-lowering therapy

BACKGROUND

Systemic inflammatory diseases have been associated with increased risk of venous thromboembolism. We aimed to quantify the risk of venous thromboembolism in patients with gout, the most common inflammatory arthritis, and to assess how disease duration, hospital admission and urate-lowering therapy affect this risk.

METHODS

We used data from the population-representative, England-based Clinical Practice Research Datalink linked to Hospital Episode Statistics, to identify incident gout cases between 1998 and 2017. We matched cases individually to 1 control without gout on age, gender, general practice and follow-up time. We calculated absolute and relative risks of venous thromboembolism, stratified by age, gender and hospital admission. Among those with gout, we assessed the risk of venous thromboembolism by exposure to urate-lowering therapy.

RESULTS

We identified 62 234 patients with incident gout matched to 62 234 controls. Gout was associated with higher risk of venous thromboembolism compared with controls (absolute rate 37.3 [95% confidence interval (CI) 35.5-39.3] v. 27.0 [95% CI 25.5-28.9] per 10 000 person-years, adjusted hazard ratio [HR] 1.25, 95% CI 1.15-1.35). The excess risk in patients with gout, which was sustained up to a decade after diagnosis, was present during the time outside hospital stay (adjusted HR 1.30, 95% CI 1.18-1.42), but not during it (adjusted HR 1.01, 95% CI 0.83-1.24). The risk of venous thromboembolism was similar among patients prescribed versus not prescribed urate-lowering therapy (incidence rate ratio 1.04, 95% CI 0.89-1.23).

INTERPRETATION

Gout was associated with higher risk of venous thromboembolism, particularly when the patient was not in hospital and regardless of exposure to urate-lowering therapy. Although the observed excess risk may not be sufficient to warrant preventive intervention, clinical vigilance may be required when caring for these patients.

Interstitial lung disease is a risk factor for ischaemic heart disease and myocardial infarction

Objectives

Despite many shared risk factors and pathophysiological pathways, the risk of ischaemic heart disease (IHD) and myocardial infarction (MI) in interstitial lung disease (ILD) remains poorly understood. This lack of data could be preventing patients who may benefit from screening for these cardiovascular diseases from receiving it.

Methods

A population-based cohort study used electronic patient records from the Clinical Practice Research Datalink and linked Hospital Episode Statistics to identify 68 572 patients (11 688 ILD exposed (mean follow-up: 3.8 years); 56 884 unexposed controls (mean follow-up: 4.0 years), with 349 067 person-years of follow-up. ILD-exposed patients (pulmonary sarcoidosis (PS) or idiopathic pulmonary fibrosis (PF)) were matched (by age, sex, registered general practice and available follow-up time) to patients without ILD or IHD/MI. Rates of incident MI and IHD were estimated. HRs were modelled using multivariable Cox proportional hazards regression accounting for potential confounders.

Results

ILD was independently associated with IHD (HR 1.85, 95% CI 1.56 to 2.18) and MI (HR 1.74, 95% CI 1.44 to 2.11). In all disease categories, risk of both IHD and MI peaked between ages 60 and 69 years, except for the risk of MI in PS which was greatest <50 years. Men with PF were at greatest risk of IHD, while women with PF were at greatest risk of MI.

Conclusions

ILD, particularly PF, is independently associated with MI and IHD after adjustment for established cardiovascular risk factors. Our results suggest clinicians should prioritise targeted assessment of cardiovascular risk in patients with ILD, particularly those aged 60–69 years. Further research is needed to understand the impact of such an approach to risk management.

Emergence of Multidrug- and Pandrug- Resistant Pseudomonas aeruginosa from Five Hospitals in Qatar

Background

A global rise in multidrug-resistant (MDR) nosocomial infections has led to a significant increase in morbidity and mortality. MDR Gram-negative bacteria (GNB) are recognised for rapidly developing drug resistance. Despite Pseudomonas aeruginosa being the second most common GNB isolated from healthcare associated infections, the magnitude of MDR P. aeruginosa (MDR-PA) has not been evaluated in Qatar.

Aim

To assess the prevalence and antimicrobial susceptibility patterns of MDR-PA from 5 major hospitals in Qatar.

Methods

A total of 2533 P. aeruginosa clinical isolates were collected over a one-year period. MDR-PA was defined as resistance to at least one agent of ≥ 3 antibiotic classes. Clinical and demographic data were collected prospectively.

Findings

The overall prevalence of MDR-PA isolates was 8.1% (205/2533); the majority of isolates were from patients exposed to antibiotics during 90 days prior to isolation (85.4 %, 177/205), and the infections were mainly hospital-acquired (95.1%, 195/205) with only 4.9% from the community. The majority of MDR-PA isolates were resistant to cefepime (96.6%, 198/205), ciprofloxacin, piperacillin/tazobactam (91%, 186/205), and meropenem (90%, 184/205). Patient comorbidities with MDR-PA were diabetes mellitus (47.3%, n=97), malignancy (17.1%, n=35), end-stage renal disease (13.7%, n=28) and heart failure (10.7%, n=22).

Conclusion

There was a significant prevalence of MDR-PA in Qatar, primarily from healthcare facilities and associated with prior antibiotic treatment. There was an alarming level of antimicrobial resistance to carbapenems. Our results are part of a national surveillance of MDR to establish effective containment plans.

Risk of fragility fracture among patients with gout and the effect of urate-lowering therapy

BACKGROUND

Previous studies that quantified the risk of fracture among patients with gout and assessed the potential effect of urate-lowering therapy have provided conflicting results. Our study aims to provide better estimates of risk by minimizing the effect of selection bias and confounding on the observed association.

METHODS

We used data from the Clinical Practice Research Datalink, which records primary care consultations of patients from across the United Kingdom. We identified patients with incident gout from 1990 to 2004 and followed them up until 2015. Each patient with gout was individually matched to 4 controls on age, sex and general practice. We calculated absolute rate of fracture and hazard ratios (HRs) using Cox regression models. Among patients with gout, we assessed the impact of urate-lowering therapy on fracture, and used landmark analysis and propensity score matching to account for immortal time bias and confounding by indication.

RESULTS

We identified 31 781 patients with incident gout matched to 122 961 controls. The absolute rate of fracture was similar in both cases and controls (absolute rate = 53 and 55 per 10 000 person-years, respectively) corresponding to an HR of 0.97 (95% confidence interval 0.92-1.02). Our finding remained unchanged when we stratified our analysis by age and sex. We did not observe statistically significant differences in the risk of fracture among those prescribed urate-lowering therapy within 1 and 3 years after gout diagnosis.

INTERPRETATION

Overall, gout was not associated with an increased risk of fracture. Urate-lowering drugs prescribed early during the course of disease had neither adverse nor beneficial effect on the long-term risk of fracture.

Antibiotic use and the risk of rheumatoid arthritis: a population-based case-control study

BACKGROUND

Antibiotic-induced disturbances of the human microbiota have been implicated in the development of chronic autoimmune conditions. This study aimed to assess whether antibiotic use is associated with the onset of rheumatoid arthritis (RA).

METHODS

A nested case-control study was conducted utilising data from the primary care Clinical Practice Research Datalink (CPRD). Patients with an incident diagnosis of RA were identified (1995-2017). Each case was matched on age, gender, and general practice to ≥ 5 controls without RA. Conditional logistic regression was used to examine previous antibiotic prescriptions and RA onset after controlling for confounding factors.

RESULTS

We identified 22,677 cases of RA, matched to 90,013 controls, with a median follow-up of 10 years before RA diagnosis. The odds of developing RA were 60% higher in those exposed to antibiotics than in those not exposed (OR 1.60; 95% CI 1.51-1.68). A dose- or frequency-dependent association was observed between the number of previous antibiotic prescriptions and RA. All classes of antibiotics were associated with higher odds of RA, with bactericidal antibiotics carrying higher risk than bacteriostatic (45% vs. 31%). Those with antibiotic-treated upper respiratory tract (URT) infections were more likely to be RA cases. However, this was not observed for URT infections not treated with antibiotics. Antifungal (OR = 1.27; 95% CI 1.20-1.35) and antiviral (OR = 1.19; 95% CI 1.14-1.24) prescriptions were also associated with increased odds of RA.

CONCLUSION

Antibiotic prescriptions are associated with a higher risk of RA. This may be due to microbiota disturbances or underlying infections driving risk. Further research is needed to explore these mechanisms.

Comorbidities in polymyalgia rheumatica: a systematic review

BACKGROUND AND AIM

Comorbidities are known to exist in many rheumatological conditions. Polymyalgia rheumatica (PMR) is a common inflammatory rheumatological condition affecting older people which, prior to effective treatment, causes severe disability. Our understanding of associated comorbidities in PMR is based only on case reports or series and small cohort studies. The objective of this study is to review systematically the existing literature on the comorbidities associated with PMR.

METHODS

MEDLINE, EMBASE, PsycINFO and CINAHL databases were searched for original observational research from inception to November 2016. Papers containing the words 'Polymyalgia Rheumatica' OR 'Giant Cell Arteritis' OR the terms 'PMR' OR 'GCA' were included. Article titles were reviewed based on pre-defined criteria by two reviewers. Following selection for inclusion, studies were quality assessed using the Newcastle-Ottawa tool and data were extracted.

RESULTS

A total of 17,329 papers were reviewed and 41 were incorporated in this review, including three published after the search took place. Wide variations were found in study design, comorbidities reported and populations studied. Positive associations were found between PMR diagnosis and stroke, cardiovascular disease, peripheral arterial disease, diverticular disease and hypothyroidism. Two studies reported a positive association between PMR and overall malignancy rate. Seven studies reported an association between PMR and specific types of cancer, such as leukaemia, lymphoma, myeloproliferative disease and specified solid tumours, although nine studies found either no or negative association between cancer and PMR.

CONCLUSION

Quantification of the prevalence of comorbidities in PMR is important to accurately plan service provision and enable identification of cases of PMR which may be more difficult to treat. This review highlights that research into comorbidities in PMR is, overall, methodologically inadequate and does not comprehensively cover all comorbidities. Future studies should consider a range of comorbidities in patients with a validated diagnosis of PMR in representative populations.

Risk of chronic kidney disease in patients with gout and the impact of urate lowering therapy: a population-based cohort study

Background

An association between gout and renal disease is well-recognised but few studies have examined whether gout is a risk factor for subsequent chronic kidney disease (CKD). Additionally, the impact of urate-lowering therapy (ULT) on development of CKD in gout is unclear. The objective of this study was to quantify the risk of CKD stage ≥ 3 in people with gout and the impact of ULT.

Methods

This was a retrospective cohort study using data from the Clinical Practice Research Datalink (CPRD). Patients with incident gout were identified from general practice medical records between 1998 and 2016 and randomly matched 1:1 to patients without a diagnosis of gout based on age, gender, available follow-up time and practice. Primary outcome was development of CKD stage ≥ 3 based on estimated glomerular filtration rate (eGFR) or recorded diagnosis. Absolute rates (ARs) and adjusted hazard ratios (HRs) were calculated using Cox regression models. Risk of developing CKD was assessed among those prescribed ULT within 1 and 3 years of gout diagnosis.

Results

Patients with incident gout (n = 41,446) were matched to patients without gout. Development of CKD stage ≥ 3 was greater in the exposed group than in the unexposed group (AR 28.6 versus 15.8 per 10,000 person-years). Gout was associated with an increased risk of incident CKD (adjusted HR 1.78 95% CI 1.70 to 1.85). Those exposed to ULT had a greater risk of incident CKD, but following adjustment this was attenuated to non-significance in all analyses (except on 3-year analysis of women (adjusted HR 1.31 95% CI 1.09 to 1.59)).

Conclusions

This study has demonstrated gout to be a risk factor for incident CKD stage ≥ 3. Further research examining the mechanisms by which gout may increase risk of CKD and whether optimal use of ULT can reduce the risk or progression of CKD in gout is suggested.

Electronic supplementary material

The online version of this article (10.1186/s13075-018-1746-1) contains supplementary material, which is available to authorized users.

Incidence, prevalence and treatment burden of polymyalgia rheumatica in the UK over two decades: a population-based study

Objective

Polymyalgia rheumatica (PMR) is the most common inflammatory rheumatic disease in older people. Contemporary estimates of the incidence and prevalence are lacking, and no previous study has assessed treatment patterns at a population level. This study aims to address this.

Methods

We extracted anonymised electronic medical records of patients over the age of 40 years from the Clinical Practice Research Datalink in the period 1990–2016. The absolute rate of PMR per 100 000 person-years was calculated and stratified by age, gender and calendar year. Incidence rate ratios were calculated using a Poisson regression model. Among persons with PMR, continuous and total duration of treatment with glucocorticoids (GC) were assessed.

Results

5 364 005 patients were included who contributed 44 million person-years of follow-up. 42 125 people had an incident diagnosis of PMR during the period. The overall incidence rate of PMR was 95.9 per 100 000 (95% CI 94.9 to 96.8). The incidence of PMR was highest in women, older age groups and those living in the South of England. Incidence appears stable over time. The prevalence of PMR in 2015 was 0.85 %. The median (IQR) continuous GC treatment duration was 15.8 (7.9–31.2) months. However, around 25% of patients received more than 4 years in total of GC therapy.

Conclusions

The incidence rates of PMR have stabilised. This is the first population-based study to confirm that a significant number of patients with PMR receive prolonged treatment with GC, which can carry significant risks. The early identification of these patients should be a priority in future research.

Antifolate drug resistance: Novel mutations and haplotype distribution in dhps and dhfr from Northeast India

Malaria is a major public health concern in Northeast India with a preponderance of drug-resistant strains. Until recently the partner drug for artemisinin combination therapy (ACT) was sulphadoxine pyrimethamine (SP). Antifolate drug resistance has been associated with the mutations at dihydropteroate synthase (dhps) and dihydrofolatereductase (dhfr) genes. This study investigated antifolate drug resistance at the molecular level. A total of 249 fever cases from Arunachal Pradesh, NE India, were screened for malaria, and of these, 75 were found to be positive for Plasmodium falciparum. Samples were sequenced and analysed with the help of BioEdit and ClustalW. Three novel point mutations were found in the dhps gene with 10 haplotypes along with the already reported mutations. A single haplotype having quadruple mutation was found in the dhfr gene. The study reports higher degree of antifolate drug resistance as evidenced by the presence of multiple point mutations in dhps and dhfr genes. The findings of this study strongly discourage the use SP as a partner drug in ACT.

Are adverse outcome rates higher in multiple sclerosis patients after total hip arthroplasty?

Aims

This study compared multiple sclerosis (MS) patients who underwent primary total hip arthroplasty (THA) with a matched cohort. Specifically, we evaluated: 1) implant survivorship; 2) functional outcomes (modified Harris Hip Scores (mHHS), Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS JR), and modified Multiple Sclerosis Impact Scale (mMSIS) scores (with the MS cohort also evaluated based on the disease phenotype)); 3) physical therapy duration and return to function; 4) radiographic outcomes; and 5) complications.

Patients and Methods

We reviewed our institution's database to identify MS patients who underwent THA between January 2008 and June 2016. A total of 34 MS patients (41 hips) were matched in a 1:2 ratio to a cohort of THA patients who did not have MS, based on age, body mass index (BMI), and Charlson/Deyo score. Patient records were reviewed for complications, and their functional outcomes and radiographs were reviewed at their most recent follow-up.

Results

Compared with the matched cohort, MS patients had lower all-cause implant survivorship at eight years (91.5% (95% confidence interval (CI) 82.7 to 100) vs 98.7% (95% CI 96.2 to 100)) (p = 0.033), lower mHHS scores (66 vs 80, p < 0.001), and HOOS JR scores (79 vs 88, p = 0.009). Multiple sclerosis patients also required more physiotherapy (five weeks vs three weeks, p = 0.002) and took longer to return to baseline (seven weeks vs five weeks, p = 0.010) than the matched cohort. Furthermore, MS patients had more complications than the non-MS patients (six vs zero, p < 0.001). The worse outcomes of the MS group can potentially be explained by predisposition of these patients to mechanical complications and progression of their disease during the period of this study, as demonstrated by worsening of the mMSIS scores (2.9 vs 3.4; p = 0.008).

Conclusion

MS patients had lower implant survivorship, lower functional outcome scores, and increased complication rates; in addition, MS patients took longer to return to their baseline functional level after THA. Cite this article: Bone Joint J 2018;100-B:875-81.

Risk of fracture among patients with polymyalgia rheumatica and giant cell arteritis: a population-based study

BACKGROUND

Glucocorticoids are associated with increased fracture risk and are the mainstay of treatment in polymyalgia rheumatica (PMR) and giant cell arteritis (GCA). However, fracture risk in these conditions has not been previously quantified. The aim of this study was to quantify the risk of fracture among patients with PMR and GCA.

METHODS

A retrospective cohort study was conducted using primary care records from the UK-based Clinical Practice Research Datalink. Individuals aged 40 years and over, with incident diagnoses of PMR or GCA were separately identified from 1990-2004 and followed up until 2015. For each exposed individual, four age-, sex- and practice-matched controls were randomly selected. Incidence rates of fracture per 10,000 person-years were calculated for each disease group and hazard rates were compared to the unexposed using Cox regression models.

RESULTS

Overall, 12,136 and 2673 cases of PMR and GCA, respectively, were identified. The incidence rate of fracture was 148.05 (95% CI 141.16-155.28) in PMR and 147.15 (132.91-162.91) in GCA per 10,000 person-years. Risk of fracture was increased by 63% in PMR (adjusted hazard ratio 1.63, 95% CI 1.54-1.73) and 67% in GCA (1.67, 1.49-1.88) compared to the control populations. Fewer than 13% of glucocorticoid-treated cases were prescribed bisphosphonates.

CONCLUSIONS

This study reports, for the first time, a similar increase in fracture risk for patients with PMR and GCA. More needs to be done to improve adherence to guidelines to co-prescribe bisphosphonates. Further research needs to identify whether lower glucocorticoid starting doses and/or aggressive dose reduction reduces fracture risk.

Glycaemic, gastrointestinal and appetite responses to breakfast porridges from ancient cereal grains: A MRI pilot study in healthy humans

Cereal grain based porridges are commonly consumed throughout the world. Whilst some data are available for varieties that are popular in the Western world such as oats and rye, other 'ancient' grains used in the East and in Africa such as millets are thought to have beneficial health effects, such as a suppression of post prandial hunger and circulating glucose levels. These grains, a sustainable food source due to their tolerance of extreme weather and growing conditions, are commonly found throughout Asia and Africa. However, knowledge of the physiological responses to these grain varieties is very limited. This study aimed to collect initial pilot data on the physiological and gastrointestinal responses to breakfast porridges made with two millet varieties and oats and rye grains. A total of n=15 completed the oats and rye, n=9 the finger millet n=12 the pearl millet meals. MRI scans were undertaken at baseline, immediately after consumption and then hourly postprandially. Blood glucose was measured at baseline, immediately after consumption and then every 15min until t=80min, then every 20min until t=120min, followed on each occasion by completion of VAS. Seven participants completed the entire protocol and were included in the final analysis. A subgroup analysis with the n=10 paired comparison between the same individuals that completed the oats, rye and pearl millet was also considered. The gastric volume AUC was higher for pearl millet than oats and rye (n=10, p<0.001). The incremental area under the curve (iAUC) for blood glucose was not significantly different between the meals although this showed a trend to be lower for pearl millet. Hunger was lower for pearl millet compared to oats and rye (n=10, p=0.01). There was a significant correlation between total gastric volume AUC and average appetite AUC r=-0.47, p<0.010. Isoenergetic breakfast porridges from 'ancient' varieties of millet grains showed physiological responses that were comparable with those from common Western varieties known to have beneficial health effects. Pearl millet appeared to induce lower postprandial blood glucose response and appetite scores though the differences were not conclusive compared with the other porridges and further work is needed. Improved knowledge of the effects of different cereal grains could help direct dietary advice and ultimately improve health outcomes in the general population worldwide.

Peripartum hysterectomy: an economic analysis of direct healthcare costs using routinely collected data

OBJECTIVE

To estimate resource use and costs associated with peripartum hysterectomy for the English National Health Service.

DESIGN/SETTING

Analysis of linked Clinical Practice Research Datalink and Hospital Episodes Statistics (CPRD-HES) data.

POPULATION

Women undergoing peripartum hysterectomy between 1997 and 2013 and matched controls.

METHODS

Inverse probability weighted generalised estimating equations were used to model the non-linear trend in healthcare service use and costs over time, accounting for missing data, adjusting for maternal age, body mass index, delivery year, smoking and socio-economic indicators.

MAIN OUTCOME MEASURES

Primary care, hospital outpatient and inpatient attendances and costs (UK 2015 prices).

RESULTS

The study sample included 1362 women (192 cases and 1170 controls) who gave birth between 1997 and 2013; 1088 (153 cases and 935 controls) of these were deliveries between 2003 and 2013 when all categories of hospital resource use were available. Based on the 2003-2013 delivery cohort, peripartum hysterectomy was associated with a mean adjusted additional total cost of £5380 (95% CI £4436-6687) and a cost ratio of 1.76 (95% CI 1.61-1.98) over 5 years of follow up compared with controls. Inpatient costs, mostly incurred during the first year following surgery, accounted for 78% excluding or 92% including delivery-related costs.

CONCLUSION

Peripartum hysterectomy is associated with increased healthcare costs driven largely by increased post-surgery hospitalisation rates. To reduce healthcare costs and improve outcomes for women who undergo hysterectomy, interventions that reduce avoidable repeat hospitalisations following surgery such as providing active follow up, treatment and support in the community should be considered.

TWEETABLE ABSTRACT

A large amount of NHS data on peripartum hysterectomy suggests active community follow up could reduce costs, #HealthEconomics.

Gout and subsequent erectile dysfunction: a population-based cohort study from England

Background

An association has been suggested between gout and erectile dysfunction (ED), however studies quantifying the risk of ED amongst gout patients are lacking. We aimed to precisely determine the population-level absolute and relative rate of ED reporting among men with gout over a decade in England.

Methods

We utilised the UK-based Clinical Practice Research Datalink to identify 9653 men with incident gout age- and practice-matched to 38,218 controls. Absolute and relative rates of incident ED were calculated using Cox regression models. Absolute rates within specific time periods before and after gout diagnosis were compared to control using a Poisson regression model.

Results

Overall, the absolute rate of ED post-gout diagnosis was 193 (95% confidence interval (CI): 184–202) per 10,000 person-years. This corresponded to a 31% (hazard ratio (HR): 1.31 95%CI: 1.24–1.40) increased relative risk and 0.6% excess absolute risk compared to those without gout. We did not observe statistically significant differences in the risk of ED among those prescribed ULT within 1 and 3 years after gout diagnosis. Compared to those unexposed, the risk of ED was also high in the year before gout diagnosis (relative rate = 1.63 95%CI 1.27–2.08). Similar findings were also observed for severe ED warranting pharmacological intervention.

Conclusions

We have shown a statistically significant increased risk of ED among men with gout. Our findings will have important implications in planning a multidisciplinary approach to managing patients with gout.

Incidence of First Stroke in Pregnant and Nonpregnant Women of Childbearing Age: A Population-Based Cohort Study From England

Background

Pregnant women may have an increased risk of stroke compared with nonpregnant women of similar age, but the magnitude and the timing of such risk are unclear. We examined the risk of a first stroke event in women of childbearing age and compared the risk during pregnancy and in the early postpartum period with the background risk outside these periods.

Methods and Results

We conducted an open cohort study of 2 046 048 women aged 15 to 49 years between April 1, 1997, and March 31, 2014, using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care records in England. Risk of first stroke was assessed by calculating the incidence rate of stroke in antepartum, peripartum (2 days before until 1 day after delivery), and early (first 6 weeks) and late (second 6 weeks) postpartum periods compared with nonpregnant time using a Poisson regression model with adjustment for maternal age, socioeconomic group, and calendar time. A total of 2511 women had a first stroke. The incidence rate of stroke was 25.0 per 100 000 person‐years (95% CI 24.0–26.0) in nonpregnant time. The rate was lower antepartum (10.7 per 100 000 person‐years, 95% CI 7.6–15.1) but 9‐fold higher peripartum (161.1 per 100 000 person‐years, 95% CI 80.6–322.1) and 3‐fold higher early postpartum (47.1 per 100 000 person‐years, 95% CI 31.3–70.9). Rates of ischemic and hemorrhagic stroke both increased peripartum and early postpartum.

Conclusions

Although the absolute risk of first stroke is low in women of childbearing age, healthcare professionals should be aware of a considerable increase in relative risk during the peripartum and early postpartum periods.

The incidence of first stroke in and around pregnancy: A population-based cohort study from Sweden

Introduction

Research has suggested that delivery is associated with an increased risk of stroke in women; however, there is a lack of contemporary estimates on the incidence of stroke in and after pregnancy compared with the baseline risk in women of childbearing age in Sweden.

Patients and methods

All women aged 15-49 years with live births/stillbirths in 1992-2011 were identified from the Swedish Medical Birth Registry linked with the National Patient Registry. First stroke during the study period was identified. Incidence rates per 100,000 person-years and adjusted incidence rate ratios (IRRs) were calculated for antepartum, peripartum and early and late postpartum periods, compared with all other available follow-up time (time before pregnancy and after postpartum) using Poisson regression adjusted for maternal age, education attainment and calendar time.

Results

Of 1,124,541 women, 3094 had a first incident stroke (331 occurred during pregnancy or first 12 weeks postpartum), about half having ischaemic stroke. The incidence was 15.0 per 100,000 person-years (95% confidence interval 14.5-15.6) in non-pregnant time. The incidence was lower antepartum (7.3/100,000 person-years, 6.0-8.9; adjusted IRR = 0.7, 0.5-0.8) but higher peripartum (314.4/100,000 person-years, 247.5-399.5; adjusted IRR = 27.3, 21.4-34.9) and early postpartum (64.0/100,000 person-years, 54.1-75.7; adjusted IRR = 5.5, 4.6-6.6). The increased risk in peripartum was more evident for intracerebral haemorrhage than other types of stroke.

Conclusion

Overall risk of stroke was low in women of childbearing age, but stroke risk peaks in the peripartum and early postpartum periods. Future work should address factors that contribute to this increased risk in order to develop approaches to attenuate risk.

Development and validation of risk prediction model for venous thromboembolism in postpartum women: multinational cohort study

OBJECTIVE

 To develop and validate a risk prediction model for venous thromboembolism in the first six weeks after delivery (early postpartum).

DESIGN

 Cohort study.

SETTING

 Records from England based Clinical Practice Research Datalink (CPRD) linked to Hospital Episode Statistics (HES) and data from Sweden based registry.

PARTICIPANTS

 All pregnant women registered with CPRD-HES linked data between 1997 and 2014 and Swedish medical birth registry between 2005 and 2011 with postpartum follow-up.

MAIN OUTCOME MEASURE

 Multivariable logistic regression analysis was used to develop a risk prediction model for postpartum venous thromboembolism based on the English data, which was externally validated in the Swedish data.

RESULTS

 433 353 deliveries were identified in the English cohort and 662 387 in the Swedish cohort. The absolute rate of venous thromboembolism was 7.2 per 10 000 deliveries in the English cohort and 7.9 per 10 000 in the Swedish cohort. Emergency caesarean delivery, stillbirth, varicose veins, pre-eclampsia/eclampsia, postpartum infection, and comorbidities were the strongest predictors of venous thromboembolism in the final multivariable model. Discrimination of the model was similar in both cohorts, with a C statistic above 0.70, with excellent calibration of observed and predicted risks. The model identified more venous thromboembolism events than the existing national English (sensitivity 68% v 63%) and Swedish guidelines (30% v 21%) at similar thresholds.

CONCLUSION

 A new prediction model that quantifies absolute risk of postpartum venous thromboembolism has been developed and externally validated. It is based on clinical variables that are available in many developed countries at the point of delivery and could serve as the basis for real time decisions on obstetric thromboprophylaxis.

Human papillomavirus genotypes and HPV-16 variants distribution among Tunisian women with normal cytology and squamous intraepithelial lesions

Background

Little is known about the epidemiological characteristics of papillomavirus (HPV) infection among North African countries. Herein, we conducted a molecular epidemiological study to investigate prevalence of HPV type and HPV-16 variants among cervical-screened unvaccinated Tunisian women.

Methods

Cross-sectional study was performed on 494 Tunisian women visiting Women’s Healthcare Centers. HPV-DNA detection was carried out on cervical samples using real-time polymerase chain reaction. HPV genotyping and HPV-16 variants were characterized by direct sequencing of L1 viral capsid gene.

Results

The overall HPV prevalence was 34% (95% CI: 30–38%) with significantly higher prevalence among women with squamous intraepithelial lesions (SIL) than those with no intraepithelial lesions (NIL) 84% (95% CI: 76–92%) and 24.5% (95% CI: 20–29%) respectively. The distribution of HPV prevalence according to women’s age shows a U-shaped curve and the highest HPV prevalence rates were observed among the youngest (≤25 years; 51.2%, 95% CI: 37–67%) and the oldest women (>55 years; 41.7%, 95% The HPV-16 prevalence was 32.8% (95% CI: 22–45%) among women with SIL and 9.2% (95% CI: 6–12%) among women with NIL. Whereas, the HPV-18 prevalence was 1.3% (95% CI: 0–5%) among women with SIL and 0.3% (95% CI: 0–1%) among women with NIL. Among HPV-16 positive women, European lineage (E) was identified as the predominant HPV-16 variant (85.7%, 95% CI: 76–95%). The frequency of E variant was lower among SIL than among NIL women (81%, 95% CI: 64–99%, and 88%, 95% CI: 77–100%, respectively). Conversely, the African-2 variant frequency was higher among SIL than among NIL women (18%, 95% CI: 1–36% and 6%, 95% CI: 2–14%, respectively). In multivariate analysis, young age was the only risk factor that is independently associated with HPV infection. Moreover, HPV infection and menopause were both found to be independently associated with SIL and HSIL.

Conclusion

HPV DNA testing should be proposed to young and menopausal Tunisian women. Considering HPV prevalence, only 13% of the Tunisian women could be protected by the bivalent HPV vaccine. These results may be helpful for designing an adapted HPV testing and vaccination program in Tunisia.

No increased mortality in 109,000 first-degree relatives of celiac individuals

BACKGROUND

Several studies have shown an excess mortality in individuals with celiac disease (CD). However, it is unknown if also first-degree relatives (FDRs) to celiac patients are at increased risk of death.

AIM

We aimed to assess mortality in FDRs to celiac patients.

METHODS

Individuals with CD were identified through biopsy reports (equal to Marsh grade III). Each celiac individual was matched on sex, age, county and calendar year with up to five control individuals. Through Swedish healthcare registries we identified all FDRs (father, mother, sibling, offspring) of CD individuals and controls. Through Cox regression we calculated hazard ratios (HRs) for mortality (all-cause death, circulatory, cancer and other).

RESULTS

We identified 109,309 FDRs of celiac individuals and 549,098 FDRs of controls. Overall mortality was increased in FDRs to celiac individuals (HR=1.02, 95%CI=1.00-1.04, p=0.03). This corresponded to an excess risk of 5.9 deaths per 100,000 person-years of follow-up. When limiting follow-up to time since celiac diagnosis in the index individual, we found no increased risk of death (HR=1.01; 95%CI=0.98-1.03).

CONCLUSION

FDRs to individuals with CD are at increased risk of death. This excess risk is however minimal and unlikely to be of any clinical importance to the individual.

Abstract 140: Incidence of Stroke in and Around Pregnancy: A UK Population-based Cohort Study

Introduction: There are very few population-based studies on the incidence of stroke in women of childbearing age, stratifying by stroke types and pregnancy-related periods.

Methods: We used an open cohort study design including all women aged 15-49 years from UK linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care records in 1997-2014. The exposure of our study was pregnancy resulting in a live or a stillbirth and associated antenatal and postpartum periods. The outcome of the study was the first ever stroke diagnosis, defined using ICD-10 codes (I60-I64, O22.5 and O87.3) or relevant Read codes, and classified as having ischaemic stroke (IS), intracerebral haemorrhage (ICH), subarachnoid haemorrhage (SAH) or unspecified. We calculated the absolute rates of stroke per 100,000 person-years and 95% confidence intervals (95%CI) for different exposure periods. We stratified the analysis by maternal age and types of stroke.

Results: Of 2,047,858 women, we identified 336,957 women with 453,776 deliveries. There were totally 2,526 women with a first incidence of stroke: IS 1,140 (45.1%), SAH 684 (27.1%), ICH 368 (14.6%) and unspecified 334 (13.2%). The overall incidence rate of stroke was 24.9 (95%CI 23.6-26.2) per 100,000 person-years in the non-pregnant period (IS 11.2 [10.4-12.1], ICH 3.6 [3.2-4.2], SAH 6.8 [6.2-7.5] and unspecified 3.3 [2.9-3.8]). The incidence was however higher around delivery (281.9 [141.6-561.2]) and in the first six weeks postpartum (43.8 [25.3-75.9]) and the rate ratios compared to the non-pregnant period after adjusting for age were 19.2 (9.6-38.3) and 3.0 (1.7-5.2) respectively.

Conclusions: Although the incidence of stroke for young women was relatively low, the incidence around delivery or in the early postpartum was significantly higher compared to other periods, regardless of maternal age.

Risk of symptomatic venous thromboembolism following emergency appendicectomy in adults

Background

Appendicectomy is the commonest intra-abdominal emergency surgical procedure, and little is known regarding the magnitude and timing of the risk of venous thromboembolism (VTE) after surgery. This study aimed to determine absolute and relative rates of symptomatic VTE following emergency appendicectomy.

Methods

A cohort study was undertaken using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care data of patients who had undergone emergency appendicectomy from 2001 to 2011. Crude rates and adjusted incidence rate ratios (IRRs) for VTE were calculated using Poisson regression, compared with baseline risk in the year before appendicectomy.

Results

A total of 13 441 patients were identified, of whom 56 (0·4 per cent) had a VTE in the first year after surgery. The absolute rate of VTE was highest during the in-hospital period, with a rate of 91·29 per 1000 person-years, which was greatest in those with a length of stay of 7 days or more (267·12 per 1000 person-years). This risk remained high after discharge, with a 19·1- and 6·6-fold increased risk of VTE in the first and second months respectively after discharge, compared with the year before appendicectomy (adjusted IRR: month 1, 19·09 (95 per cent c.i. 9·56 to 38·12); month 2, 6·56 (2·62 to 16·44)).

Conclusion

The risk of symptomatic VTE following appendicectomy is relatively high during the in-hospital admission and remains increased after discharge. Trials of extended thromboprophylaxis are warranted in patients at particularly high risk.

Defining venous thromboembolism and measuring its incidence using Swedish health registries: a nationwide pregnancy cohort study

OBJECTIVE

To accurately define venous thromboembolism (VTE) in the routinely collected Swedish health registers and quantify its incidence in and around pregnancy.

STUDY DESIGN

Cohort study using data from the Swedish Medical Birth Registry (MBR) linked to the National Patient Registry (NPR) and the Swedish Prescribed Drug Register (PDR).

SETTING

Secondary care centres, Sweden.

PARTICIPANT

509,198 women aged 15-44 years who had one or more pregnancies resulting in a live birth or stillbirth between 2005 and 2011.

MAIN OUTCOME MEASURE

To estimate the incidence rate (IR) of VTE in and around pregnancy using various VTE definitions allowing direct comparison with other countries.

RESULTS

The rate of VTE varied based on the VTE definition. We found that 43% of cases first recorded as outpatient were not accompanied by anticoagulant prescriptions, whereas this proportion was much lower than those cases first recorded in the inpatient register (9%). Using our most inclusive VTE definition, we observed higher rates of VTE compared with previously published data using similar methodology. These reduced by 31% (IR=142/100,000 person-years; 95% CI 132 to 153) and 22% (IR=331/100,000 person-years; 95% CI 304 to 361) during the antepartum and postpartum periods, respectively, using a restrictive VTE definition that required anticoagulant prescriptions associated with diagnosis, which were more in line with the existing literature.

CONCLUSIONS

We found that including VTE codes without treatment confirmation risks the inclusion of false-positive cases. When defining VTE using the NPR, anticoagulant prescription information should therefore be considered particularly for cases recorded in an outpatient setting.

Causes of death in people with coeliac disease in England compared with the general population: a competing risk analysis

INTRODUCTION

Quantifying excess cause-specific mortality among people with coeliac disease (CD) compared with the general population accounting for competing risks will allow accurate information to be given on risk of death from specific causes.

METHOD

We identified from the Clinical Practice Research Datalink all patients with CD linked to Office for National Statistics between 1998 and 2012. We selected controls by frequency matching from the registered general practice population within 10-year age bands. We calculated the adjusted cumulative incidence (including adjustment for competing risks) and excess cumulative incidence for different causes of death up to 10 years from diagnosis.

RESULTS

Of the 10 825 patients with CD, 773 died within the study period. The overall mortality rate among patients with CD was 128/10 000 person years compared with 153/10 000 in controls (HR=0.94 95% CI 0.84 to 1.01). We found no overall difference in the cumulative incidence of respiratory disease, digestive disease or cancer related death among cases and controls. The adjusted cumulative incidence of death from cardiovascular deaths was slightly lower compared with those without CD diagnosis (CD 0.32% vs controls 0.41%) with a corresponding excess cumulative incidence of -0.08% (95% CI -0.13 to -0.04). However, patients with CD had 0.15% excess risk (95% CI 0.03 to 0.27) of deaths from non-Hodgkin's lymphoma from the general population baseline risk.

CONCLUSIONS

Overall, people with CD have no major excess risk of cancer, digestive disease or respiratory disease related or cardiovascular mortality compared with the general population. These findings should be reassuring to patients with CD and clinicians managing their care.

Women with celiac disease present with fertility problems no more often than women in the general population

BACKGROUND & AIMS

Studies have associated infertility with celiac disease. However, these included small numbers of women attending infertility specialist services and subsequently screened for celiac disease, and therefore may not have been representative of the general population. We performed a large population-based study of infertility and celiac disease in women from the United Kingdom.

METHODS

We identified 2,426,225 women with prospective UK primary care records between 1990 and 2013 during their child-bearing years from The Health Improvement Network database. We estimated age-specific rates of new clinically recorded fertility problems among women with and without diagnosed celiac disease. Rates were stratified by whether celiac disease was diagnosed before the fertility problem or afterward and compared with rates in women without celiac disease using Poisson regression, adjusting for sociodemographics, comorbidities, and calendar time.

RESULTS

Age-specific rates of new clinically recorded fertility problems in 6506 women with celiac disease were similar to the rates in women without celiac disease (incidence rate ratio, 1.12; 95% confidence interval, 0.88-1.42 among women age 25-29 years). Rates of infertility among women without celiac disease were similar to those of women with celiac disease before and after diagnosis. However, rates were 41% higher among women diagnosed with celiac disease when they were 25-29 years old, compared with women in the same age group without celiac disease (incidence rate ratio, 1.41; 95% confidence interval, 1.03-1.92).

CONCLUSIONS

Women with celiac disease do not have a greater likelihood of clinically recorded fertility problems than women without celiac disease, either before or after diagnosis, except for higher reports of fertility problems between 25-39 years if diagnosed with CD. These findings should assure most women with celiac disease that they do not have an increased risk for fertility problems.

Women with celiac disease present with fertility problems no more often than women in the general population

BACKGROUND & AIMS

Studies have associated infertility with celiac disease. However, these included small numbers of women attending infertility specialist services and subsequently screened for celiac disease, and therefore may not have been representative of the general population. We performed a large population-based study of infertility and celiac disease in women from the United Kingdom.

METHODS

We identified 2,426,225 women with prospective UK primary care records between 1990 and 2013 during their child-bearing years from The Health Improvement Network database. We estimated age-specific rates of new clinically recorded fertility problems among women with and without diagnosed celiac disease. Rates were stratified by whether celiac disease was diagnosed before the fertility problem or afterward and compared with rates in women without celiac disease using Poisson regression, adjusting for sociodemographics, comorbidities, and calendar time.

RESULTS

Age-specific rates of new clinically recorded fertility problems in 6506 women with celiac disease were similar to the rates in women without celiac disease (incidence rate ratio, 1.12; 95% confidence interval, 0.88-1.42 among women age 25-29 years). Rates of infertility among women without celiac disease were similar to those of women with celiac disease before and after diagnosis. However, rates were 41% higher among women diagnosed with celiac disease when they were 25-29 years old, compared with women in the same age group without celiac disease (incidence rate ratio, 1.41; 95% confidence interval, 1.03-1.92).

CONCLUSIONS

Women with celiac disease do not have a greater likelihood of clinically recorded fertility problems than women without celiac disease, either before or after diagnosis, except for higher reports of fertility problems between 25-39 years if diagnosed with CD. These findings should assure most women with celiac disease that they do not have an increased risk for fertility problems.

Pregnancy complications and adverse birth outcomes among women with celiac disease: a population-based study from England

OBJECTIVES

Evidence-based information about adverse birth outcomes and pregnancy complications is crucial when counseling women with celiac disease (CD); however, limited population-based data on such risks exist. We estimated these for pregnant women with CD diagnosed before and after delivery.

METHODS

We included all singleton pregnancies between 1997 and 2012 using linked primary care data from the Clinical Practice Research Datalink and secondary care Hospital Episode Statistics data. Risks of pregnancy complications (antepartum and postpartum hemorrhage, pre-eclampsia, and mode of delivery) and adverse birth outcomes (preterm birth, stillbirth, and low birth weight) were compared between pregnancies of women with and without CD using logistic/multinomial regression. Risks were stratified on the basis of whether women were diagnosed or yet undiagnosed before delivery.

RESULTS

Of 363,930 pregnancies resulting in a live birth or stillbirth, 892 (0.25%) were among women with CD. Diagnosed CD was not associated with an increased risk of pregnancy complications or adverse birth outcomes compared with women without CD. However, the risk of postpartum hemorrhage and assisted delivery was slightly higher among pregnant women with diagnosed CD (adjusted odds ratio (aOR)=1.34). We found no increased risk of any pregnancy complication among those with undiagnosed CD. We only observed a 1% absolute excess risk of preterm birth and low birth weight among undiagnosed CD mothers corresponding to aOR=1.24 (95% confidence interval (CI)=0.82-1.87) and aOR=1.36 (95% CI=0.83-2.24), respectively.

CONCLUSIONS

Whether diagnosed or undiagnosed during pregnancy, CD is not associated with a major increased risk of pregnancy complications and adverse birth outcomes. These findings are reassuring to both women and clinicians.

Risk of first venous thromboembolism in pregnant women in hospital: population based cohort study from England

OBJECTIVE

To examine the potential for preventing venous thromboembolism during and after antepartum hospital admissions in pregnant women.

DESIGN

Cohort study using linked primary (Clinical Practice Research Datalink) and secondary (Hospital Episode Statistics) care records.

SETTING

Primary and secondary care centres, England.

PARTICIPANTS

206,785 women aged 15-44 who had one or more pregnancies from 1997 up to 2010.

MAIN OUTCOME MEASURE

Risk of first venous thromboembolism in pregnant women admitted to hospital for one or more days for reasons other than delivery or venous thromboembolism. Risk was assessed by calculating the absolute rate of venous thromboembolism and comparing these rates with those observed during follow-up time not associated with hospital admission using a Poisson regression model to estimate incidence rate ratios.

RESULTS

Admission to hospital in pregnancy was associated with an increased risk of venous thromboembolism (absolute rate 1752/100,000 person years; incidence rate ratio 17.5, 95% confidence interval 7.69 to 40.0) compared with time outside hospital. The rate of venous thromboembolism was also high during the 28 days after discharge (absolute rate 676; 6.27, 3.74 to 10.5). The rate during and after admission combined was highest in the third trimester (961; 5.57, 3.32 to 9.34) and in those aged ≥ 35 years (1756; 21.7, 9.62 to 49.0). While the absolute rate in the combined period was highest for those with three or more days in hospital (1511; 12.2, 6.65 to 22.7), there was also a fourfold increase (558; 4.05, 2.23 to 7.38) in the risk of venous thromboembolism for those admitted to hospital for less than three days.

CONCLUSION

The overall risk of first venous thromboembolism in pregnant women increased during admissions to hospital not related to delivery, and remained significantly higher in the 28 days after discharge. During these periods need for thromboprophylaxis should receive careful consideration.

The incidence of first venous thromboembolism in and around pregnancy using linked primary and secondary care data: a population based cohort study from England and comparative meta-analysis

Background

Recent linkage between primary and secondary care data has provided valuable information for studying heath outcomes that may initially present in different health care settings. The aim of this study was therefore, twofold: to use linked primary and secondary care data to determine an optimum definition for estimating the incidence of first VTE in and around pregnancy; and secondly to conduct a systematic literature review of studies on perinatal VTE incidence with the purpose of comparing our estimates.

Methods

We used primary care data from the Clinical Practice Research Datalink (CPRD), which incorporates linkages to secondary care contained within Hospital Episode Statistics (HES) between 1997 and 2010 to estimate the incidence rate of VTE in the antepartum and postpartum period. We systematically searched the literature on the incidence of VTE during antepartum and postpartum periods and performed a meta-analysis to provide comparison.

Findings

Using combined CPRD and HES data and a restrictive VTE definition, the absolute rate during the antepartum period and first six weeks postpartum (early postpartum) were 99 (95%CI 85–116) and 468 (95%CI 391–561) per 100,000 person-years respectively. These were comparable to the pooled estimates from our meta-analysis (using studies after 2005) during the antepartum period (118/100,000 person-years) and early postpartum (424/100,000 person-years). When we used only secondary care data to identify VTE events, incidence was lower during the early postpartum period (308/100,000 person-years), whereas relying only on primary care data lead to lower incidence during the time around delivery, but higher rates during the postpartum period (558/100,000 person-years).

Conclusion

Using combined CPRD and HES data gives estimates of the risk of VTE in and around pregnancy that are comparable to the existing literature. It also provides more accurate estimation of the date of VTE diagnosis which will allow risk stratification during specific pregnancy and postpartum periods.

Complementation of Plasmodium berghei TRAP knockout parasites using human dihydrofolate reductase gene as a selectable marker

Previously we have used the Plasmodium dihydrofolate reductase thymidylate synthase (DHFR-TS) selectable marker to generate Plasmodium berghei TRAP null mutant parasites. These TRAP null mutants do not glide and they showed a great reduction in their ability to infect mosquito salivary glands and the hepatocytes of the vertebrate host. Thus far, complementation of these knockout parasites was not possible due to the lack of additional selectable markers. Recently, a new selectable marker, based on the human dihydrofolate reductase (hDHFR) gene, has been developed which confers resistance to the antifolate drug WR99210. This drug has been found to be highly active against pyrimethamine-sensitive and -resistant strains of P. berghei. In this study, we have used the hDHFR gene as a second selectable marker for the complementation of P. berghei TRAP null mutant parasites. Restoration of the TRAP null mutant parasites to the wild-type phenotype was achieved in this study via autonomously replicating episomes bearing a wild-type copy of the TRAP gene. This is the first report of complementation of a mutant phenotype in malaria parasites.

Molecular mechanisms of malaria sporozoite motility and invasion of host cells

Malaria sporozoites have the unique capacity to invade two entirely different types of target cell in the mosquito vector and the vertebrate host during the course of the parasite's life cycle. Although little is known about the specific interaction of the sporozoite with its target cells, two sporozoite proteins, circumsporozoite (CS) and thrombospondin-related adhesive protein (TRAP), have been shown to play important roles in the invasion of both cell types. CS protein is a multifunctional protein involved in sporogony, invasion of the salivary glands, the specific arrest of sporozoites in the liver sinusoid, gliding motility of the sporozoite, and hepatocyte recognition and entry. TRAP has been shown to be critical for sporozoite infection of the mosquito salivary glands and liver cells, and is essential for sporozoite gliding motility. This review will focus on the involvement of these molecules in sporozoite motility and the invasion of host cells.

Green fluorescent protein as a marker in Plasmodium berghei transformation

We present a new marker that confers both resistance to pyrimethamine and green fluorescent protein-based fluorescence on the malarial parasite Plasmodium berghei. A single copy of the cassette integrated into the genome is sufficient to direct fluorescence in parasites throughout the life cycle, in both its mosquito and vertebrate hosts. Erythrocyte stages of the parasite that express the marker can be sorted from control parasites by flow cytometry. Pyrimethamine pressure is not necessary for maintaining the cassette in transformed parasites during their sporogonic cycle in mosquitoes, including when it is borne by a plasmid. This tool should thus prove useful in molecular studies of P. berghei, both for generating parasite variants and monitoring their behavior.

Subtle mutagenesis by ends-in recombination in malaria parasites

The recent advent of gene-targeting techniques in malaria (Plasmodium) parasites provides the means for introducing subtle mutations into their genome. Here, we used the TRAP gene of Plasmodium berghei as a target to test whether an ends-in strategy, i.e., targeting plasmids of the insertion type, may be suitable for subtle mutagenesis. We analyzed the recombinant loci generated by insertion of linear plasmids containing either base-pair substitutions, insertions, or deletions in their targeting sequence. We show that plasmid integration occurs via a double-strand gap repair mechanism. Although sequence heterologies located close (less than 450 bp) to the initial double-strand break (DSB) were often lost during plasmid integration, mutations located 600 bp and farther from the DSB were frequently maintained in the recombinant loci. The short lengths of gene conversion tracts associated with plasmid integration into TRAP suggests that an ends-in strategy may be widely applicable to modify plasmodial genes and perform structure-function analyses of their important products.