Validity of diagnostic coding within the General Practice Research Database: a systematic review

Epidemiology and outcomes of gastroparesis, as documented in general practice records, in the United Kingdom

OBJECTIVE

To generate real-world evidence for the epidemiology of gastroparesis in the UK, we evaluated the prevalence, incidence, patient characteristics and outcomes of gastroparesis in the Clinical Practice Research Datalink (CPRD) database.

DESIGN

This was a retrospective, cross-sectional study. Prevalence and incidence of gastroparesis were evaluated in the CPRD database, with linkage to Hospital Episodes Statistics Admitted Patient Care and Office for National Statistics mortality data. Prevalence and incidence were age and sex standardised to mid-2017 UK population estimates. Descriptive analyses of demographics, aetiologies, pharmacological therapies and mortality were conducted.

RESULTS

Standardised prevalence of gastroparesis, as documented in general practice records, was 13.8 (95% CI 12.6 to 15.1) per 100 000 persons in 2016, and standardised incidence of gastroparesis rose from 1.5 (95% CI 1.1 to 1.8) per 100 000 person-years in 2004 to 1.9 (95% CI 1.4 to 2.3) per 100 000 person-years in 2016. The most common disease aetiologies were idiopathic (39.4%) and diabetic gastroparesis (37.5%), with a similar distribution of type 1 and type 2 diabetes among the 90% who had type of diabetes documented. Patients with diabetic gastroparesis had a significantly higher risk of mortality than those with idiopathic gastroparesis after diagnosis (adjusted HR 1.9, 95% CI 1.2 to 3.0). Of those with gastroparesis, 31.6% were not offered any recognised pharmacological therapy after diagnosis.

CONCLUSION

This is, to our knowledge, the first population-based study providing data on epidemiology and outcomes of gastroparesis in Europe. Further research is required to fully understand the factors influencing outcomes and survival of patients with gastroparesis.

Concomitant use of oral glucocorticoids and proton pump inhibitors and risk of osteoporotic fractures among patients with rheumatoid arthritis: a population-based cohort study

BACKGROUND

Patients with rheumatoid arthritis (RA) commonly use oral glucocorticoids (GCs) and proton pump inhibitors (PPIs), both associated with osteoporotic fractures. We investigated the association between concomitant use of oral GCs and PPIs and the risk of osteoporotic fractures among patients with RA.

METHODS

This was a cohort study including patients with RA aged 50+ years from the Clinical Practice Research Datalink between 1997 and 2017. Exposure to oral GCs and PPIs was stratified by the most recent prescription as current use (<6 months), recent use (7-12 months) and past use (>1 year); average daily and cumulative dose; and duration of use. The risk of incident osteoporotic fractures (including hip, vertebrae, humerus, forearm, pelvis and ribs) was estimated by time-dependent Cox proportional-hazards models, statistically adjusted for lifestyle parameters, comorbidities and comedications.

RESULTS

Among 12 351 patients with RA (mean age of 68 years, 69% women), 1411 osteoporotic fractures occurred. Concomitant current use of oral GCs and PPIs was associated with a 1.6-fold increased risk of osteoporotic fractures compared with non-use (adjusted HR: 1.60, 95% CI: 1.35 to 1.89). This was statistically different from a 1.2-fold increased osteoporotic fracture risk associated with oral GC or PPI use alone. Most individual fracture sites were significantly associated with concomitant use of oral GCs and PPIs. Among concomitant users, fracture risk did not increase with higher daily dose or duration of PPI use.

CONCLUSIONS

There was an interaction in the risk of osteoporotic fractures with concomitant use of oral GCs and PPIs. Fracture risk assessment could be considered when a patient with RA is co-prescribed oral GCs and PPIs.

Validity of bariatric surgery codes in the UK Clinical Practice Research Datalink (CPRD) GOLD compared with Hospital Episodes Statistics

OBJECTIVES

To assess completeness and validity of bariatric surgery codes in the UK Clinical Practice Research Datalink (CPRD) GOLD compared with Hospital Episodes Statistics (HES).

METHODS

We conducted a validation study among patients in the UK-based CPRD GOLD with linkage to HES (1998 to 2017). Since the same surgery codes are used for bariatric and other gastrointestinal surgery we assessed code distribution patterns used in patients with bariatric versus other gastrointestinal surgery by presence of other conditions such as obesity and gastrointestinal cancer. We developed algorithms to identify bariatric surgery and calculated validity measures (ie, positive/negative predictive value [PPV/NPV], sensitivity, and specificity) of each in CPRD GOLD compared with HES (gold standard).

RESULTS

Among 7 357 007 available patients we identified 10 190 patients who had a total of 14 046 potential bariatric surgery codes in CPRD GOLD and/or HES. Surgery code patterns differed between bariatric surgery and assumed other gastrointestinal surgery. The sensitivity of CPRD GOLD bariatric surgery coding improved from an overall of 56% to 69-71% when applying stricter algorithms (ie, in obese patients or obese, gastrointestinal disease/complication free patients) but PPVs remained at 53%-55%. NPVs and specificities of CPRD GOLD bariatric surgery coding achieved ≥99.8% for all algorithms.

CONCLUSION

Our results suggest that using CPRD GOLD and HES data and a wide selection of surgery codes will result in the most complete and accurate capture of bariatric surgery events. Validity measures of CPRD GOLD bariatric surgery codes were identical in obese patients and more restrictive populations.

Association Between Alopecia Areata and Natural Hair Color Among White Individuals

IMPORTANCE

Alopecia areata (AA) is a complex immune-mediated disorder that causes nonscarring hair loss. Previous reports have documented preferential targeting of pigmented hair follicles with sparing of gray, nonpigmented hair follicles in alopecia lesions. Thus, immune targeting of melanogenesis-associated proteins in melanocytes and keratinocytes represents a potential mechanism for the inflammation that targets anagen hairs in alopecia areata.

OBJECTIVE

To investigate the association of alopecia areata with hair color among White residents of the UK.

DESIGN, SETTING, AND PARTICIPANTS

This matched, case-control study conducted in October 2020 used a large prospectively acquired cohort and included data that were collected from the UK Biobank, a large-scale prospective resource designed to study phenotypic and genotypic determinants in adults. A total of 502 510 UK Biobank participants were reviewed for inclusion. Among these individuals, 1673 cases of alopecia areata with reported hair color were captured and matched by age and sex to 6692 controls without alopecia areata using 1:4 matching.

MAIN OUTCOMES AND MEASURES

Conditional logistic regression analysis was performed, in which the outcome variable was alopecia areata and the main predictor was natural hair color before graying. The variables considered included diabetes, hypothyroidism, hyperthyroidism, and vitiligo.

RESULTS

Of 464 353 participants, 254 505 (54.8%) were women, and the mean (SD) age for those with alopecia areata was 46.9 (16.5) years. Alopecia areata was significantly more common in individuals with black (adjusted odds ratio [aOR], 2.97; 95% CI, 2.38-3.71) and dark brown hair (aOR, 1.26; 95% CI, 1.11-1.42) compared with light brown hair. In contrast, blond individuals exhibited significantly decreased alopecia areata compared with those with light brown hair (aOR, 0.69; 95% CI, 0.56-0.85). Red hair color was not significantly different from light brown hair.

CONCLUSIONS AND RELEVANCE

The findings of this matched case-control study seem to indicate that alopecia areata is modulated by natural hair color, preferentially targeting darker hair. Our results support a previously proposed model of alopecia areata in which immunity is directed against melanogenesis-associated proteins in the anagen hair follicles. However, further study is needed to more precisely understand the immunopathogenic association between alopecia areata and hair color.

Temporal relationship between osteoarthritis and comorbidities: a combined case control and cohort study in the UK primary care setting

Objective

To determine the burden of comorbidities in OA and their temporal relationships in the UK.

Methods

The Clinical Practice Research Datalink (CPRD) GOLD was used to identify people with incident OA and age, gender and practice matched non-OA controls from UK primary care. Controls were assigned the same index date as matched cases (date of OA diagnosis). Associations between OA and 49 individual comorbidities and multimorbidities (two or more comorbidities excluding OA) both before and after OA diagnosis were estimated, adjusting for covariates, using odds ratios (aORs) and hazard ratios (aHRs), respectively.

Results

During 1997–2017, we identified 221 807 incident OA cases and 221 807 matched controls. Of 49 comorbidities examined, 38 were associated with OA both prior to and following the diagnosis of OA and 2 (dementia and systemic lupus erythematosus) were associated with OA only following the diagnosis of OA. People with OA had a higher risk of developing heart failure [aHR 1.63 (95% CI 1.56, 1.71)], dementia [aHR 1.62 (95% CI 1.56, 1.68)], liver diseases [aHR 1.51 (95% CI 1.37, 1.67)], irritable bowel syndrome [aHR 1.51 (95% CI 1.45, 1.58)], gastrointestinal bleeding [aHR 1.49 (95% CI 1.39, 1.59)], 10 musculoskeletal conditions and 25 other conditions following OA diagnosis. The aOR for multimorbidity prior to the index date was 1.71 (95% CI 1.69, 1.74), whereas the aHR for multimorbidity after the index date was 1.29 (95% CI 1.28, 1.30).

Conclusions

People with OA are more likely to have other chronic conditions both before and after the OA diagnosis. Further study on shared aetiology and causality of these associations is needed.

Trends in predominant causes of death in individuals with and without diabetes in England from 2001 to 2018: an epidemiological analysis of linked primary care records

BACKGROUND

The prevalence of diabetes has increased in the UK and other high-income countries alongside a substantial decline in cardiovascular mortality. Yet data are scarce on how these trends have changed the causes of death in people with diabetes who have traditionally died primarily of vascular causes. We estimated how all-cause mortality and cause-specific mortality in people with diabetes have changed over time, how the composition of the mortality burden has changed, and how this composition compared with that of the non-diabetes population.

METHODS

In this epidemiological analysis of primary care records, we identified 313 907 individuals with diabetes in the Clinical Practice Research Datalink, a well described primary care database, between 2001 to 2018, and linked these data to UK Office for National Statistics mortality data. We assembled serial cross sections with longitudinal follow-up to generate a mixed prevalence and incidence study population of patients with diabetes. We used discretised Poisson regression models to estimate annual death rates for deaths from all causes and 12 specific causes for men and women with diabetes. We also identified age-matched and sex matched (1:1) individuals without diabetes from the same dataset and estimated mortality rates in this group.

FINDINGS

Between Jan 1, 2001, and Oct 31, 2018, total mortality declined by 32% in men and 31% in women with diagnosed diabetes. Death rates declined from 40·7 deaths per 1000 person-years to 27·8 deaths per 1000 person-years in men and from 42·7 deaths per 1000 person-years to 29·5 deaths per 1000 person-years in women with diagnosed diabetes. We found similar declines in individuals without diabetes, hence the gap in mortality between those with and without diabetes was maintained over the study period. Cause-specific death rates declined in ten of the 12 cause groups, with exceptions in dementia and liver disease, which increased in both populations. The large decline in vascular disease death rates led to a transition from vascular causes to cancers as the leading contributor to death rates in individuals with diagnosed diabetes and to the gap in death rates between those with and without diabetes.

INTERPRETATION

The decline in vascular death rates has been accompanied by a diversification of causes in individuals with diagnosed diabetes and a transition from vascular diseases to cancers as the leading contributor to diabetes-related death. Clinical and preventative approaches must reflect this trend to reduce the excess mortality risk in individuals with diabetes.

FUNDING

Wellcome Trust.

Trends in generalised anxiety disorders and symptoms in primary care: UK population-based cohort study

BACKGROUND

Generalised anxiety disorder and symptoms are associated with poor physical, emotional and social functioning and frequent primary and acute care visits. We investigated recent temporal trends in anxiety and related mental illness in UK general practice.

AIMS

The aims of this analysis are to examine temporal changes in recording of generalised anxiety in primary care and initial pharmacologic treatments.

METHOD

Annual incidence rates of generalised anxiety diagnoses and symptoms were calculated from 795 UK general practices contributing to The Health Improvement Network (THIN) database between 1998 and 2018. Poisson mixed regression was used to account for age, gender and general practitioner practice. Subsequent pharmacologic treatment was examined.

RESULTS

Generalised anxiety recording rates increased in both genders aged 18-24 between 2014 and 2018. For women, the increase was from 17.06 to 23.33/1000 person years at risk (PYAR); for men, 8.59 to 11.65/1000 PYAR. Increases persisted for a composite of anxiety and depression (49.74 to 57.81/1000 PYAR for women; 25.41 to 31.45/1000 PYAR for men). Smaller increases in anxiety were seen in both genders age 25-34 and 35-44. Anxiety rates among older patients remained stable, although a composite of anxiety and depression decreased for older women. About half of drug-naïve patients were prescribed anxiety drugs within 1 year following diagnosis. The most common choice was a selective serotonin reuptake inhibitor. Benzodiazepine prescription rate has fallen steadily.

CONCLUSIONS

We observed a substantial increase in general practitioner consulting for generalised anxiety and depression recently, concentrated within younger people and in particular women.

Time trends in the incidence of clinically diagnosed type 2 diabetes and pre-diabetes in the UK 2009-2018: a retrospective cohort study

INTRODUCTION

To describe recent trends in the incidence of clinically diagnosed type 2 diabetes and pre-diabetes in people seen in UK general practice.

RESEARCH DESIGN AND METHODS

A retrospective cohort study using IQVIA Medical Research Data looking at people newly diagnosed with type 2 diabetes and pre-diabetes through primary care registers in the UK between 1 January 2009 and 31 December 2018.

RESULTS

A cohort of 426 717 people were clinically diagnosed with type 2 diabetes and 418 656 people met the criteria for a diagnosis of pre-diabetes in that time period. The incidence of clinically diagnosed type 2 diabetes per 1000 person years at risk (PYAR) in men decreased from a peak of 5.06 per 1000 PYAR (95% CI 4.97 to 5.15) in 2013 to 3.56 per 1000 PYAR (95% CI 3.46 to 3.66) by 2018. For women, the incidence of clinically diagnosed type 2 diabetes per 1000 PYAR decreased from 4.45 (95% CI 4.37 to 4.54) in 2013 to 2.85 (2.76 to 2.93) in 2018. The incidence rate of pre-diabetes tripled by the end of the same study period in men and women.

CONCLUSIONS

Between 2009 and 2018, the incidence rate of new clinical diagnoses of type 2 diabetes recorded in a UK primary care database decreased by a third from its peak in 2013-2014, while the incidence of pre-diabetes has tripled. The implications of this on timely treatment, complication rates and mortality need further longer term exploration.

Impact of prescription patterns of antithrombotic treatment on atrial fibrillation-related ischemic stroke

OBJECTIVE

To analyze the temporal trends of atrial fibrillation (AF)-related ischemic stroke (IS) and their relationship with the prescription patterns of antithrombotic treatment from 2013 to 2019 in the Health Assistance Area of a regional hospital.

METHODS

First, a retrospective ecological study of aggregate data to analyze the annual incidence of IS between 2013 and 2019 was performed. Second, we selected those patients diagnosed with AF between 2013 and 2019 and performed a retrospective longitudinal study to assess the role of antithrombotic therapy in the development of AF-related IS.

RESULTS

During this period, whereas the annual incidence of IS remained stable (from 1.3 in 2013 to 1.2 cases per 1000 inhabitants in 2019; adjusted P for trend .829), the annual incidence of AF-related IS decreased over time (from 23.8 to 18.8 cases per 1000 inhabitants, respectively; adjusted P for trend .001). Among AF patients, the use of direct oral anticoagulants increased from 5.5% to 46.8%, while the prescription of antiplatelets and vitamin K antagonists decreased from 21.9% to 6.0% and from 63.8% to 36.1%, respectively. Overall, the use of oral anticoagulants increased from 69.3% to 82.9%; p < .001. Patients under antiplatelet agents had a higher probability of presenting IS than those patients taking oral anticoagulants, either vitamin K antagonists or direct oral anticoagulants (adjusted OR 1.89; 95% CI 1.52-2.37; p < .001).

CONCLUSIONS

The prescription of oral anticoagulants, particularly direct oral anticoagulants, has increased from 2013 to 2019 in our Health Assistance Area. This increase might partially explain the reduction in AF-related IS.

Incidence, Prevalence, and Health Care Outcomes in Idiopathic Intracranial Hypertension: A Population Study

OBJECTIVE

To characterize trends in incidence, prevalence, and health care outcomes in the idiopathic intracranial hypertension (IIH) population in Wales using routinely collected health care data.

METHODS

We used and validated primary and secondary care IIH diagnosis codes within the Secure Anonymised Information Linkage databank to ascertain IIH cases and controls in a retrospective cohort study between 2003 and 2017. We recorded body mass index (BMI), deprivation quintile, CSF diversion surgery, and unscheduled hospital admissions in case and control cohorts.

RESULTS

We analyzed 35 million patient-years of data. There were 1,765 cases of IIH in 2017 (85% female). The prevalence and incidence of IIH in 2017 was 76/100,000 and 7.8/100,000/y, a significant increase from 2003 (corresponding figures = 12/100,000 and 2.3/100,000/y) (p < 0.001). IIH prevalence is associated with increasing BMI and increasing deprivation. The odds ratio for developing IIH in the least deprived quintile compared to the most deprived quintile, adjusted for sex and BMI, was 0.65 (95% confidence interval 0.55 to 0.76). Nine percent of IIH cases had CSF shunts with less than 0.2% having bariatric surgery. Unscheduled hospital admissions were higher in the IIH cohort compared to controls (rate ratio 5.28, p < 0.001) and in individuals with IIH and CSF shunts compared to those without shunts (rate ratio 2.02, p < 0.01).

CONCLUSIONS

IIH incidence and prevalence is increasing considerably, corresponding to population increases in BMI, and is associated with increased deprivation. This has important implications for health care professionals and policy makers given the comorbidities, complications, and increased health care utilization associated with IIH.

Data-driven identification of ageing-related diseases from electronic health records

Reducing the burden of late-life morbidity requires an understanding of the mechanisms of ageing-related diseases (ARDs), defined as diseases that accumulate with increasing age. This has been hampered by the lack of formal criteria to identify ARDs. Here, we present a framework to identify ARDs using two complementary methods consisting of unsupervised machine learning and actuarial techniques, which we applied to electronic health records (EHRs) from 3,009,048 individuals in England using primary care data from the Clinical Practice Research Datalink (CPRD) linked to the Hospital Episode Statistics admitted patient care dataset between 1 April 2010 and 31 March 2015 (mean age 49.7 years (s.d. 18.6), 51% female, 70% white ethnicity). We grouped 278 high-burden diseases into nine main clusters according to their patterns of disease onset, using a hierarchical agglomerative clustering algorithm. Four of these clusters, encompassing 207 diseases spanning diverse organ systems and clinical specialties, had rates of disease onset that clearly increased with chronological age. However, the ages of onset for these four clusters were strikingly different, with median age of onset 82 years (IQR 82–83) for Cluster 1, 77 years (IQR 75–77) for Cluster 2, 69 years (IQR 66–71) for Cluster 3 and 57 years (IQR 54–59) for Cluster 4. Fitting to ageing-related actuarial models confirmed that the vast majority of these 207 diseases had a high probability of being ageing-related. Cardiovascular diseases and cancers were highly represented, while benign neoplastic, skin and psychiatric conditions were largely absent from the four ageing-related clusters. Our framework identifies and clusters ARDs and can form the basis for fundamental and translational research into ageing pathways.

Antidiabetic Treatment, Level of Glycemic Control, and Risk of Fracture in Type 2 Diabetes: a Nested, Case-Control Study

CONTEXT

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of low-trauma fractures. However, the effect of antidiabetic medication in relation to glycemic control on the risk of fracture is poorly understood.

OBJECTIVE

This work aimed to evaluate the association between the level of glycemic control, use of antidiabetic medication, and risk of low-trauma fractures in patients with newly diagnosed T2DM.

METHODS

We conducted a nested case-control analysis among individuals registered in the Clinical Practice Research Datalink. The base population consisted of patients with newly diagnosed T2DM from 1995 to 2017. Cases were patients with a low-trauma fracture after T2DM diagnosis. We matched 4 controls to each case. Exposures of interest were glycemic control (last glycated hemoglobin [HbA1c] level before fracture) and type of diabetes treatment. We conducted conditional logistic regression analyses adjusted for several confounders.

RESULTS

We identified 8809 cases and 35 219 controls. Patients with current metformin use and HbA1c levels of less than 7.0% and between 7.0-8.0% had a reduced risk of fractures (adjusted odds ratio 0.89; 95% CI, 0.83-0.96 and 0.81; 95% CI, 0.73-0.90, respectively) compared with untreated patients. However, in patients receiving metformin plus 1 or 2 other antidiabetic drugs, or insulin (alone or in addition to other antidiabetic medication), the level of glycemic control was not associated with the risk of fracture compared with untreated patients.

CONCLUSIONS

While patients with good or medium glycemic control receiving current metformin monotherapy had a lower risk of fracture compared with untreated patients, glycemic control in patients receiving treatment other than metformin was not associated with risk of fracture.

Cardiovascular events and mortality in people with type 2 diabetes and multimorbidity: A real-world study of patients followed for up to 19 years

AIM

To quantify the risk of cardiovascular disease (CVD) events, all-cause mortality and cardiovascular mortality in patients diagnosed with type 2 diabetes (T2D) and multimorbidity.

METHODS

This retrospective study used English primary and secondary care data to identify 120 409 adults newly diagnosed with T2D during 2000-2018 with follow-up until death or 31 December 2018. Patients were classified according to the level and type of multimorbidity at T2D diagnosis, and adjusted hazard ratios (aHRs) were calculated for each outcome.

RESULTS

In total, 66 977 (55.6%) patients had T2D only, 37 894 (31.5%) had one co-morbidity, 11 357 (9.4%) had two co-morbidities, 3186 (2.6%) patients had three co-morbidities and 995 (0.8%) patients had four or more co-morbidities. Co-morbidities were associated with increased aHRs for all outcomes. Compared with patients with T2D only, at 19 years after diagnosis of T2D the aHR for four or more co-morbidities was 2.57 (95% CI 2.45-2.69) for a CVD event, 1.73 (1.68-1.78) for all-cause mortality and 2.68 (2.52-2.85) for cardiovascular mortality. Also, 100 183 (83.2%) patients had no CVD co-morbidities, 16 874 (14.0%) patients had one CVD co-morbidity and 3352 (2.8%) patients had two or more co-morbidities. Compared with patients with no CVD co-morbidities, at 19 years after diagnosis of T2D the aHR for two or more CVD co-morbidities was 2.42 (2.35-2.49) for a CVD event, 1.44 (1.42-1.47) for all-cause mortality and 2.44 (2.35-2.54) for cardiovascular mortality.

CONCLUSION

In people with T2D, level of multimorbidity and, in particular, CVD multimorbidity increased the risk of subsequent CVD events, mortality and cardiovascular mortality.

Non-benzodiazepine hypnotic use for sleep disturbance in people aged over 55 years living with dementia: a series of cohort studies

BACKGROUND

Sleep disturbance affects around 60% of people living with dementia and can negatively affect their quality of life and that of their carers. Hypnotic Z-drugs (zolpidem, zopiclone and zaleplon) are commonly used to treat insomnia, but their safety and efficacy have not been evaluated for people living with dementia.

OBJECTIVES

To estimate the benefits and harms of Z-drugs in people living with dementia with sleep disturbance.

DESIGN

A series of observational cohort studies using existing data from (1) primary care linked to hospital admission data and (2) clinical cohort studies of people living with dementia.

DATA SOURCES

Primary care study - Clinical Practice Research Datalink linked to Hospital Episode Statistics and Office for National Statistics mortality data. Clinical cohort studies - the Resource Use and Disease Course in Dementia - Nursing Homes (REDIC) study, National Alzheimer's Coordinating Centre (NACC) clinical data set and the Improving Well-being and Health for People with Dementia (WHELD) in nursing homes randomised controlled trial.

SETTING

Primary care study - 371 primary care practices in England. Clinical cohort studies - 47 nursing homes in Norway, 34 Alzheimer's disease centres in the USA and 69 care homes in England.

PARTICIPANTS

Primary care study - NHS England primary care patients diagnosed with dementia and aged > 55 years, with sleep disturbance or prescribed Z-drugs or low-dose tricyclic antidepressants, followed over 2 years. Clinical cohort studies - people living with dementia consenting to participate, followed over 3 years, 12 years and 9 months, for REDIC, NACC and WHELD, respectively.

INTERVENTIONS

The primary exposure was prescription or use of Z-drugs. Secondary exposures included prescription or use of benzodiazepines, low-dose tricyclic antidepressants and antipsychotics.

MAIN OUTCOME MEASURES

Falls, fractures, infection, stroke, venous thromboembolism, mortality, cognitive function and quality of life. There were insufficient data to investigate sleep disturbance.

RESULTS

The primary care study and combined clinical cohort studies included 6809 and 18,659 people living with dementia, with 3089 and 914 taking Z-drugs, respectively. New Z-drug use was associated with a greater risk of fractures (hazard ratio 1.40, 95% confidence interval 1.01 to 1.94), with risk increasing with greater cumulative dose (p = 0.002). The hazard ratio for Z-drug use and hip fracture was 1.59 (95% confidence interval 1.00 to 2.53) and for mortality was 1.34 (95% confidence interval 1.10 to 1.64). No excess risks of falls, infections, stroke or venous thromboembolism were detected. Z-drug use also did not have an impact on cognition, neuropsychiatric symptoms, disability or quality of life.

LIMITATIONS

Primary care study - possible residual confounding because of difficulties in identifying patients with sleep disturbance and by dementia severity. Clinical cohort studies - the small numbers of people living with dementia taking Z-drugs and outcomes not necessarily being measured before Z-drug initiation restricted analyses.

CONCLUSIONS

We observed a dose-dependent increase in fracture risk, but no other harms, with Z-drug use in dementia. However, multiple outcomes were examined, increasing the risk of false-positive findings. The mortality association was unlikely to be causal. Further research is needed to confirm the increased fracture risk. Decisions to prescribe Z-drugs may need to consider the risk of fractures, balanced against the impact of improved sleep for people living with dementia and that of their carers. Our findings suggest that when Z-drugs are prescribed, falls prevention strategies may be needed, and that the prescription should be regularly reviewed.

FUTURE WORK

More research is needed on safe and effective management strategies for sleep disturbance in people living with dementia.

STUDY REGISTRATION

This study is registered as European Union electronic Register of Post-Authorisation Studies (EU PAS) 18006.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 1. See the NIHR Journals Library website for further project information.

The Number of Concomitant Drugs and the Safety of Direct Oral Anticoagulants in Routine Care Patients with Atrial Fibrillation

Background  The benefit of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) on major bleeding was less prominent among atrial fibrillation (AF) patients with polypharmacy in post-hoc randomized controlled trials analyses. Whether this phenomenon also exists in routine care is unknown. The aim of the study is to investigate whether the number of concomitant drugs prescribed modifies safety and effectiveness of DOACs compared with VKAs in AF patients treated in general practice.

Study Design  Adult, nonvalvular AF patients with a first DOAC or VKA prescription between January 2010 and July 2018 were included, using data from the United Kingdom Clinical Practice Research Datalink. Primary outcome was major bleeding, secondary outcomes included types of major bleeding, nonmajor bleeding, ischemic stroke, and all-cause mortality. Effect modification was assessed using Cox proportional hazard regression, stratified for the number of concomitant drugs into three strata (0–5, 6–8, ≥9 drugs), and by including the continuous variable in an interaction term with the exposure (DOAC vs. VKA).

Results  A total of 63,600 patients with 146,059 person-years of follow-up were analyzed (39,840 person-years of DOAC follow-up). The median age was 76 years in both groups, the median number of concomitant drugs prescribed was 7. Overall, the hazard of major bleeding was similar between VKA-users and DOAC-users (hazard ratio [HR] 0.98; 95% confidence interval [CI] 0.87–1.11), though for apixaban a reduction in major bleeding was observed (HR 0.81; 95% CI 0.68–0.98). Risk of stroke was comparable, while risk of nonmajor bleeding was lower in DOAC users compared with VKA users (HR 0.92; 95% CI 0.88–0.97). We did not observe any evidence for an impact of polypharmacy on the relative risk of major bleeding between VKA and DOAC across our predefined three strata of concomitant drug use ( p -value for interaction = 0.65). For mortality, however, risk of mortality was highest among DOAC users, increasing with polypharmacy and independent of the type of DOAC prescribed ( p -value for interaction <0.01).

Conclusion  In this large observational, population-wide study of AF patients, risk of bleeding, and ischemic stroke were comparable between DOACs and VKAs, irrespective of the number of concomitant drugs prescribed. In AF patients with increasing polypharmacy, our data appeared to suggest an unexplained yet increased risk of mortality in DOAC-treated patients, compared with VKA recipients.

Comparative effectiveness and safety of direct oral anticoagulants versus warfarin in UK patients with atrial fibrillation and type 2 diabetes: A retrospective cohort study

PURPOSE

To estimate the effectiveness and safety of direct oral anticoagulants (DOACs) compared with warfarin in AF patients with type 2 diabetes (T2DM).

METHODS

A retrospective cohort study was designed, using the UK Clinical Practice Research Datalink (August 2011-June 2018). Participants were 1-year naïve users of DOACs or warfarin, followed from the date of first prescription of an oral anticoagulant until the end of the study period, death, discontinuation of treatment, switching to another anticoagulant, or an outcome of interest, whichever came first. Cox regression analysis was performed to estimate the hazard ratio (HR) adjusted for potential confounders.

RESULTS

A total of 8555 patients were identified. No significant differences were found between DOACs and warfarin in the risk of stroke (adjusted HR 1.15; 95% CI 0.82-1.60), ischemic and unspecified stroke (adjusted HR 1.23; 95% CI 0.86-1.76) or haemorrhagic stroke (adjusted HR 0.75; 95% CI 0.30-1.85), and myocardial infarction (adjusted HR 1.39;95% CI 0.99-1.97). DOAC and warfarin users were comparable with respect to risk of major bleed (adjusted HR 0.83; 95% CI 0.68-1.03), intracranial bleeding (HR 0.66; 95% CI 0.34-1.30), gastrointestinal bleeding (HR 0.88; 95% CI 0.60-1.30), and bleeding on other clinically relevant sites (HR 0.89; 95% CI 0.60-1.31). In the subgroup analyses stratified by gender and diabetes severity, the risk for stroke and bleeding remained consistent.

CONCLUSION

DOACs are effective and safe alternatives to warfarin for the prevention of stroke in AF patients with T2DM.

Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies

BACKGROUND

Knee osteoarthritis (OA) is a major cause of disability in the elderly, however, there are few studies to estimate the global prevalence, incidence, and risk factors of knee OA.

METHODS

For this study, we searched PUBMED, EMBASE and SCOPUS from inception to April 4, 2020, without language restriction. We identified eligible studies with information on the prevalence or incidence of knee OA in population-based observational studies and extracted data from published reports. We did random-effects meta-analysis to generate estimates. This study was registered with PROSPERO (CRD42020181035).

FINDINGS

Out of 9570 records identified, 88 studies with 10,081,952 participants were eligible for this study. The pooled global prevalence of knee OA was 16⋅0% (95% CI, 14⋅3%-17⋅8%) in individuals aged 15 and over and was 22⋅9% (95% CI, 19⋅8%-26⋅1%) in individuals aged 40 and over. Correspondingly, there are around 654⋅1 (95% CI, 565⋅6-745⋅6) million individuals (40 years and older) with knee OA in 2020 worldwide. The pooled global incidence of knee OA was 203 per 10,000 person-years (95% CI, 106-331) in individuals aged 20 and over. Correspondingly, there are around annual 86⋅7 (95% CI, 45⋅3-141⋅3) million individuals (20 years and older) with incident knee OA in 2020 worldwide. The prevalence and incidence varied substantially between individual countries and increased with age. The ratios of prevalence and incidence in females and males were 1⋅69 (95% CI, 1⋅59-1⋅80, p<0⋅00) and 1⋅39 (95% CI, 1⋅24-1⋅56, p<0⋅00), respectively.

INTERPRETATION

Our study provides the global prevalence (16⋅0% [95% CI, 14⋅3%-17⋅8%]) and incidence (203 per 10,000 person-years [95% CI, 106-331]) of knee OA. These findings can be used to better assess the global health burden of knee OA. Further prospective cohort studies are warranted to identify modifiable risk factors for providing effectively preventive strategies in the early stages of the disease.

FUNDING

This work was supported by grants from the National Natural Science Foundation of China (nos. 81772384 and 81572174).

Adverse effects of Z-drugs for sleep disturbance in people living with dementia: a population-based cohort study

BACKGROUND

Sleep disturbance is common in dementia and often treated with Z-drugs (zopiclone, zaleplon, and zolpidem). While some observational studies suggest that Z-drugs are associated with adverse events such as falls and fracture risks in older people, this has not been studied in dementia.

METHODS

We used data from 27,090 patients diagnosed with dementia between January 2000 and March 2016 from the Clinical Practice Research Datalink linked to Hospital Episodes Statistics data in England. We compared adverse events for 3532 patients newly prescribed Z-drugs by time-varying dosage to (1) 1833 non-sedative-users with sleep disturbance; (2) 10,214 non-sedative-users with proximal GP consultation matched on age, sex, and antipsychotic use; and (3) 5172 patients newly prescribed benzodiazepines. We defined higher dose Z-drugs and benzodiazepines as prescriptions equivalent to ≥ 7.5 mg zopiclone or > 5 mg diazepam daily. Cox regression was used to estimate hazard ratios (HRs) for incident fracture, hip fracture, fall, mortality, acute bacterial infection, ischaemic stroke/transient ischaemic attack, and venous thromboembolism over a 2-year follow-up, adjusted for demographic- and health-related covariates.

RESULTS

The mean (SD) age of patients was 83 (7.7) years, and 16,802 (62%) were women. Of 3532 patients prescribed Z-drugs, 584 (17%) were initiated at higher doses. For patients prescribed higher dose Z-drugs relative to non-users with sleep disturbance, the HRs (95% confidence interval) for fractures, hip fractures, falls, and ischaemic stroke were 1.67 (1.13-2.46), 1.96 (1.16-3.31), 1.33 (1.06-1.66), and 1.88 (1.14-3.10), respectively. We observed similar associations when compared to non-sedative-users with proximal GP consultation. Minimal or inconsistent excess risks were observed at ≤ 3.75 mg zopiclone or equivalent daily, and for mortality, infection, and venous thromboembolism. We observed no differences in adverse events for Z-drugs compared to benzodiazepines, except lower mortality rates with Z-drugs (HR [95% confidence interval] of 0.73 [0.64-0.83]).

CONCLUSIONS

Higher dose Z-drug use in dementia is associated with increased fracture and stroke risks, similar or greater to that for higher dose benzodiazepines. Higher dose Z-drugs should be avoided, if possible, in people living with dementia, and non-pharmacological alternatives preferentially considered. Prescriptions for higher dose Z-drugs in dementia should be regularly reviewed.

TRIAL REGISTRATION

ENCePP e-register of studies, EUPAS18006.

Real-world reproducibility study characterizing patients newly diagnosed with multiple myeloma using Clinical Practice Research Datalink, a UK-based electronic health records database

Purpose

We evaluated the reproducibility of a study characterizing newly‐diagnosed multiple myeloma (MM) patients within an electronic health records (EHR) database using different analytic tools.

Methods

We reproduced the findings of a descriptive cohort study using an iterative two‐phase approach. In Phase I, a common protocol and statistical analysis plan (SAP) were implemented by independent investigators using the Aetion Evidence Platform® (AEP), a rapid‐cycle analytics tool, and SAS statistical software as a gold standard for statistical analyses. Using the UK Clinical Practice Research Datalink (CPRD) dataset, the study included patients newly diagnosed with MM within primary care setting and assessed baseline demographics, conditions, drug exposure, and laboratory procedures. Phase II incorporated analysis revisions based on our initial comparison of the Phase I findings. Reproducibility of findings was evaluate by calculating the match rate and absolute difference in prevalence between the SAS and AEP study results.

Results

Phase I yielded slightly discrepant results, prompting amendments to SAP to add more clarity to operational decisions. After detailed specification of data and operational choices, exact concordance was achieved for the number of eligible patients (N = 2646), demographics, comorbidities (i.e., osteopenia, osteoporosis, cardiovascular disease [CVD], and hypertension), bone pain, skeletal‐related events, drug exposure, and laboratory investigations in the Phase II analyses.

Conclusions

In this reproducibility study, a rapid‐cycle analytics tool and traditional statistical software achieved near‐exact findings after detailed specification of data and operational choices. Transparency and communication of the study design, operational and analytical choices between independent investigators were critical to achieve this reproducibility.

Increasing cancer risk over calendar year in people with multiple sclerosis: a case-control study

Background

Data on cancer prevalence and incidence in multiple sclerosis (MS) patients are controversial. This study is aimed at estimating cancer risk in MS patients.

Methods

Nested case–control study using data collected between 01/01/1987 and 28/02/2016 from the United Kingdom Clinical Practice Research Datalink. Cancer diagnoses after first MS code (index date) was counted in 10,204 MS patients and 39,448 controls matched by sex, age, general practitioner, and registration year. Cancer rates were compared using multivariable Cox regression models. Ethics approval was not required.

Results

Cancer was reported in 433 (4.41%) MS patients and 2014 (5.31%) controls after index date. Cancer risk was associated with gender (HR for female = 0.88, 95% CI = 0.81–0.96, p = 0.004), age at index date (HR = 1.06, 95% CI = 1.06–1.07, p < 0.001), and index year (HR = 1.01, 95% CI = 1.00–1.02, p = 0.016), but not with MS status (HR = 0.95, 95% CI = 0.86–1.05, p = 0.323). A significant interaction between MS status and index year was found (HR = 1.02, 95% CI = 1.00–1.04, p = 0.022). Cancer risk was positively associated with index year among MS patients (HR = 1.03, 95% CI = 1.01–1.05; p = 0.010), but not controls (HR = 1.01, 95% CI = 0.99–1.02; p = 0.144). MS patients compared to controls had no increased risk for any specific cancer type.

Conclusions

Overall cancer risk was similar in multiple sclerosis patients and matched controls. The frequency of cancer diagnoses has increased over time among MS patients but not in controls.

Electronic supplementary material

The online version of this article (10.1007/s00415-020-10170-5) contains supplementary material, which is available to authorized users.

Antiseizure drugs and risk of developing smoking-related chronic obstructive pulmonary disease or lung cancer: A population-based case-control study

AIMS

To determine whether enzyme-inducing antiseizure drugs (ASDs) affect the risk of developing chronic obstructive pulmonary disease (COPD) or lung cancer in smokers.

METHODS

Cases of COPD and lung cancer and matched controls without these conditions were identified from a population of smokers with ≥1 prescription for any type of ASD in the Clinical Practice Research Datalink UK database of patients managed in primary care (1995-2016). A matched case-control study was performed utilising multivariate logistic regression analyses of exposure to enzyme-inducing ASDs compared to non-enzyme-inducing ASDs. The duration of ASD exposure and level of tobacco exposure were also assessed.

RESULTS

We identified 5952 incident COPD and 1373 incident lung cancer cases, and 59 328 and 13 681 matched controls, respectively. Compared with never use, ever use of enzyme-inducing ASDs was associated with slightly decreased risk estimates of COPD (adjusted odds ratio: 0.85, 95% confidence interval: 0.81-0.89) and lung cancer (adjusted odds ratio: 0.82, 95% confidence interval: 0.73-0.92). These risk estimates were attenuated in heavy smokers.

CONCLUSION

We found slightly decreased risk estimates of COPD and lung cancer among smokers taking enzyme-inducing ASDs and hypothesise that this may be related to induction of detoxification of tobacco-specific lung toxins.

Post-diagnostic antipsychotic use and cancer mortality: a population based cohort study

BACKGROUND

Many antipsychotics elevate prolactin, a hormone implicated in breast cancer aetiology however no studies have investigated antipsychotic use in patients with breast cancer. This study investigated if antipsychotic use is associated with an increased risk of cancer-specific mortality among breast cancer patients.

METHODS

A cohort of 23,695 women newly diagnosed with a primary breast cancer between 1st January 1998 and 31st December 2012 was identified from the UK Clinical Practice Research Datalink linked to English cancer-registries and followed for until 30th September 2015. Time-dependent Cox proportional hazards models were used to calculate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer-specific mortality comparing use of antipsychotics with non-use, overall, and by prolactin elevating activitiy. Analyses were repeated restricting to patients with a history of severe mental illness to control for potential confounding by indication.

RESULTS

In total 848 patients were prescribed an antipsychotic and of which 162 died due to their breast cancer. Compared with non-use, antipsychotic use was associated with an increased risk of breast-cancer specific mortality (HR 2.25, 95%CI 1.90-2.67), but this did not follow a dose response relation. Restricting the cohort to patients with severe mental illness attenuated the association between antipsychotic use and breast cancer-specific mortality (HR 1.11, 95%CI 0.58-2.14).

CONCLUSIONS

In this population-based cohort of breast cancer patients, while the use of antipsychotics was associated with increased breast cancer-specific mortality, there was a lack of a dose response, and importantly null associations were observed in patients with severe mental illness, suggesting the observed association is likely a result of confounding by indication. This study provides an exemplar of confounding by indication, highlighting the importance of consideration of this important bias in studies of drug effects in cancer patients.

β 2-Agonists and the Incidence of Parkinson Disease

A recent study found a decreased risk of Parkinson disease (PD) associated with the β2 adrenergic agonist (β2-agonist) salbutamol. However, other mechanisms might explain this apparent association. Using the UK Clinical Practice Research Datalink, we formed a cohort of 2,430,884 patients aged 50 years or older between 1995 and 2016. During follow-up, 8,604 cases of PD were identified and matched to 86,040 controls on sex, age, date of cohort entry, and duration of follow-up, after applying a 1-year latency time window. Incidence rate ratios of PD associated with use of β2-agonists were estimated using conditional logistic regression. Ever-use of β2-agonists was associated with a 17% decreased rate of PD (rate ratio = 0.83, 95% confidence interval: 0.75, 0.91) compared with no use. However, this association was limited to early short-term use and was no longer observed after more than 2 years of cumulative duration of use (rate ratio = 0.97, 95% confidence interval: 0.80, 1.17). A similar pattern was observed when stratifying by time since first β2-agonist prescription and by duration of follow-up. The apparent association of β2-agonists with a decreased risk of PD is likely the result of reverse causality rather than a biological effect of these drugs on the risk of PD.

Missed Opportunities for Timely Recognition of Chronic Limb Threatening Ischaemia in Patients Undergoing a Major Amputation: A Population Based Cohort Study Using the UK's Clinical Practice Research Datalink

OBJECTIVE

Opportunities for timely recognition of chronic limb-threatening ischaemia (CLTI) within primary care, such as performing cardiovascular assessment during clinical consultation, are possibly being missed. This study aimed to investigate for potential "missed opportunities" within primary care.

METHODS

This was a population based cohort study, using the UK's Clinical Practice Research Datalink (CPRD). Patients undergoing a major amputation for CLTI between 1 January 2000 and 31 December 2016 were included. Primary care consultation and patient clinical data within the one year period prior to amputation were extracted from the CPRD. Dates of last primary care consultation and cardiovascular assessment prior to amputation were evaluated. Timings of latest cardiovascular assessments were stratified into "recent" (7-90 days before amputation) and "late" (> 91 days).

RESULTS

In total, 3 260 patients were included. In the year prior to amputation, patients attended a median of 19 (range 9-32) primary care consultations; however, prescription of secondary preventive medications was poor (antiplatelet 49.7%; lipid lowering agent 40.7%). Overall, 2 175 patients (66.7%) attended a primary care consultation 7-30 days before their amputation. However, only 416 (12.8%) underwent a cardiovascular assessment within this period, with 2 073 (63.6%) undergoing no assessment within 90 days of their amputation. Of these 2 073 patients, 1 230 (59.3%) had a primary care consultation 7-30 days before their procedure. Patients undergoing "late" assessment were younger (p = .003), with higher systolic (p = .008) and diastolic (p = .001) blood pressures than those undergoing "recent" assessment. Differences were also observed between assessment timings by deprivation (p = .003) and ethnicity (p = .006).

CONCLUSION

Missed opportunities for timely recognition potentially exist and may be related to age, deprivation, and ethnicity. Further work is required to investigate these factors, as well as individual amputations to identify the causes precipitating amputation. Greater emphasis on the medical management of peripheral arterial disease and identifying cardiovascular risk factors in patients who may not fit the "at risk" stereotype, are also required.

Paediatric contacts with the UK out-of-hours primary care service and contact outcomes: a regional service evaluation

BACKGROUND

Demand on hospital emergency departments for paediatric problems is increasing. However, the volume and nature of paediatric health demands placed on other parts of the urgent care system have not been explored. This understanding is an important first step in developing and improving out-of-hospital care. We aimed to describe the volume, nature, and outcomes of paediatric contacts with out-of-hours general practice (OOH GP). We performed a retrospective service evaluation using data from 12 months of paediatric patient contacts with the Oxfordshire OOH GP service.

METHODS

A database of contacts with the Oxfordshire OOH GP service was created for a 12 month period from December 2014 to November 2015. Descriptive statistics were calculated using SPSS Version 25.

RESULTS

27,455 contacts were made by 18,987 individuals during a 12 month period. The majority of these were for children aged under 5. Over 70% of contacts were at the weekend. The peak contact period was between 18:30 and 21:30. Over 40% of contacts resulted in advice only (no onward referral, requirement for GP follow up, or prescription). 19.7% of contacts resulted in an antibiotic prescription, most commonly those linked with ear, chest, and throat infections.

DISCUSSION

Paediatric contacts with the Oxfordshire OOH GP service were predominantly in younger age groups and in the evening, with 19.7% resulting in an antibiotic prescription. Almost half of the contacts had no follow up or prescription, suggesting non-prescribing health care professionals could be involved in providing care in OOH GP. Further research should consider how children and their parents can be best supported to optimise OOH consulting.

GP coding behaviour for non-specific clinical presentations: a pilot study

Background

Clinical coding is an integral part of primary care. Disease incidence studies based on primary care electronic health records (EHRs) rely on the accuracy of these codes. Current code validation methods are not appropriate for non-specific conditions and provide limited information about GPs' decision-making behaviour around coding. Qualitative methods could offer insight into decision-making behaviour around coding of patients with non-specific conditions.

Aim

To investigate the decision-making behaviour of GPs when applying Read codes to non-specific clinical presentations, using Lyme disease as a case example.

Design & setting

A pilot study was undertaken, involving masked semi-structured interviews of eight GPs in the North West of England.

Method

Semi-structured interviews were carried out based on 11 clinical cases representative of Lyme disease presentations. Discrete answers were described descriptively. Interview transcripts were analysed using a thematic approach.

Results

Themes underpinning GPs’ coding behaviour included: GP personal and professional experience; clinical evidence; diagnostic uncertainty; professional integrity and defensive practice; and patient-sourced health information and beliefs. GPs placed Lyme disease on their differential diagnosis list for five cases; in only two cases would GPs select a Lyme disease related Read code.

Conclusion

GPs were reluctant to code with specific diagnostic Read codes when they were presented with patients with vague or unfamiliar symptomology. This masked questionnaire methodology offers a new approach to validate incidence figures, based on Read codes of non-specific conditions. The reluctance to code poses many problems for primary care EHRs research. Further research is needed to understand what drives GPs’ coding behaviour.

Incidence, prevalence and mortality of autoimmune hepatitis in England 1997-2015. A population-based cohort study

BACKGROUND & AIMS

There are few population-based studies of the incidence and mortality of autoimmune hepatitis. The burden of the disease and how it has changed over time have not been fully explored. We conducted a population-based cohort study on the incidence and mortality of autoimmune hepatitis in England, 1997-2015.

METHODS

From the Clinical Practice Research Datalink we included 882 patients diagnosed with autoimmune hepatitis in England, 1997-2015. The patients were followed through 2015, and we calculated the sex- and age-standardized incidence and prevalence of autoimmune hepatitis. We examined variation in incidence by sex, age, calendar year, geographical region and socioeconomic status, and incidence rate ratios were calculated with Poisson regression. We calculated all-cause and cause-specific mortality.

RESULTS

The overall standardized incidence rate of autoimmune hepatitis was 2.08 (95% confidence interval 1.94-2.22) per 100,000 population per year, higher in women, higher in older age and independent of region and socioeconomic status. From 1997 to 2015 the incidence doubled from 1.27 (95% confidence interval 0.51-2.02) to 2.56 (95% confidence interval 1.79-3.33) per 100,000 population per year. The 10-year cumulative all-cause mortality was 31.9% (95% confidence interval 27.6-36.5), and the 10-year cumulative liver-related mortality, including hepatocellular carcinoma was ~10.5%.

CONCLUSIONS

This population-based study showed that the incidence of autoimmune hepatitis doubled over an eighteen-year period. The incidence was particularly high in older women and was similar across all regions of England and independent of socioeconomic status. Patients with autoimmune hepatitis had a high mortality.

Approximate Bayesian Bootstrap procedures to estimate multilevel treatment effects in observational studies with application to type 2 diabetes treatment regimens

Randomized clinical trials are considered as the gold standard for estimating causal effects. Nevertheless, in studies that are aimed at examining adverse effects of interventions, randomized trials are often impractical because of ethical and financial considerations. In observational studies, matching on the generalized propensity scores was proposed as a possible solution to estimate the treatment effects of multiple interventions. However, the derivation of point and interval estimates for these matching procedures can become complex with non-continuous or censored outcomes. We propose a novel Approximate Bayesian Bootstrap algorithm that results in statistically valid point and interval estimates of the treatment effects with categorical outcomes. The procedure relies on the estimated generalized propensity scores and multiply imputes the unobserved potential outcomes for each unit. In addition, we describe a corresponding interpretable sensitivity analysis to examine the unconfoundedness assumption. We apply this approach to examine the cardiovascular safety of common, real-world anti-diabetic treatment regimens for type 2 diabetes mellitus in a large observational database.

Rivaroxaban was found to be noninferior to warfarin in routine clinical care: A retrospective noninferiority cohort replication study

Purpose

To compare the effectiveness and safety of a drug in daily practice with the outcomes of a target non‐inferiority trial by rigorously mimickingin an observational study the trial's design features.

Methods

This cohort study was conducted using the British Clinical Practice Research Datalink (CPRD) to emulate the ROCKET AF (Rivaroxaban Once Daily Oral Direct Factor Xa Inhibition Compared with Vitamin K Antagonism for Prevention of Stroke and Embolism Trial in Atrial Fibrillation) trial. Patients with atrial fibrillation who were newly prescribed (>=12 months of no use) either rivaroxaban or warfarinfrom October 2008 to December 2017 were included. Non‐inferiority of rivaroxaban to warfarin in the prevention of stroke or systemic embolism was assessed in different analysis populations (intention‐to‐treat [ITT], per‐protocol [PP], and as‐treated populations) using a hazardratio (HR) of 1.46 as the non‐inferiority margin. Major bleeding (safety outcome) was also assessed and compared to that of the target trial. All outcomes were analyzed using Cox‐proportional hazard analyses.

Results

We included 25,473 incident users of rivaroxaban (n=4,008) or warfarin(n=21,465). Similar to the trial, non‐inferiority in the primary out come was demonstrated in all three analysis populations: HR=1.04 (95%CI 0.84 to 1.30) (ITT), HR=0.98 (95%CI 0.70 to 1.38) (PP), and HR=1.11 (95%CI 0.86 to 1.42) (as‐treated). Risk of major bleeding was also similar to the target trial.

Conclusion

The results of this study provide supportive evidence to the effectiveness of rivaroxaban and adds knowledge on the usefulness of emulating a non‐inferiority trial to assess drug effectiveness.

Diagnostic tests and treatment procedures performed prior to cardiovascular death in individuals with severe mental illness

OBJECTIVE

To examine whether severe mental illnesses (i.e., schizophrenia or bipolar disorder) affected diagnostic testing and treatment for cardiovascular diseases in primary and specialized health care.

METHODS

We performed a nationwide study of 72 385 individuals who died from cardiovascular disease, of whom 1487 had been diagnosed with severe mental illnesses. Log-binomial regression analysis was applied to study the impact of severe mental illnesses on the uptake of diagnostic tests (e.g., 24-h blood pressure, glucose/HbA1c measurements, electrocardiography, echocardiography, coronary angiography, and ultrasound of peripheral vessels) and invasive cardiovascular treatments (i.e., revascularization, arrhythmia treatment, and vascular surgery).

RESULTS

Patients with and without severe mental illnesses had similar prevalences of cardiovascular diagnostic tests performed in primary care, but patients with schizophrenia had lower prevalences of specialized cardiovascular examinations (prevalence ratio (PR) 0.78; 95% CI 0.73-0.85). Subjects with severe mental illnesses had lower prevalences of invasive cardiovascular treatments (schizophrenia, PR 0.58; 95% CI 0.49-0.70, bipolar disorder, PR 0.78; 95% CI 0.66-0.92). The prevalence of invasive cardiovascular treatments was similar in patients with and without severe mental illnesses when cardiovascular disease was diagnosed before death.

CONCLUSION

Better access to specialized cardiovascular examinations is important to ensure equal cardiovascular treatments among individuals with severe mental illnesses.

Disease misclassification in electronic healthcare database studies: Deriving validity indices-A contribution from the ADVANCE project

There is a strong and continuously growing interest in using large electronic healthcare databases to study health outcomes and the effects of pharmaceutical products. However, concerns regarding disease misclassification (i.e. classification errors of the disease status) and its impact on the study results are legitimate. Validation is therefore increasingly recognized as an essential component of database research. In this work, we elucidate the interrelations between the true prevalence of a disease in a database population (i.e. prevalence assuming no disease misclassification), the observed prevalence subject to disease misclassification, and the most common validity indices: sensitivity, specificity, positive and negative predictive value. Based on this, we obtained analytical expressions to derive all the validity indices and true prevalence from the observed prevalence and any combination of two other parameters. The analytical expressions can be used for various purposes. Most notably, they can be used to obtain an estimate of the observed prevalence adjusted for outcome misclassification from any combination of two validity indices and to derive validity indices from each other which would otherwise be difficult to obtain. To allow researchers to easily use the analytical expressions, we additionally developed a user-friendly and freely available web-application.

Quality and completeness of diagnoses recorded in the new CPRD Aurum Database: evaluation of pulmonary embolism

PURPOSE

The Clinical Practice Research Datalink (CPRD) now provides a new medical record database, CPRD Aurum. This is the first of several studies being undertaken to assess the quality and completeness of CPRD Aurum data for research endeavors.

METHODS

We identified patients with a pulmonary embolism (PE) diagnosis from a random sample of 50 000 patients in CPRD Aurum and compared the diagnoses using data from Hospital Episode Statistics (HES). We calculated the proportion of PE cases recorded in CPRD Aurum who also had a PE diagnosis recorded in HES. We also evaluated completeness by identifying all PE diagnoses in HES and calculating the proportion also present in CPRD Aurum.

RESULTS

The study included 781 PE patients: 580 had a PE in CPRD Aurum, 632 had a PE in HES, and 431 had a PE in both. The proportion of patients with anticoagulated PE in CPRD Aurum confirmed by HES was 76.8%. The completeness of primary hospitalized PE HES events compared to CPRD Aurum was 79.1%. In most instances, there was a plausible explanation for the presence of a PE in only one of the two data sources.

CONCLUSIONS

The results of this study are reassuring and suggest that the correctness (eg, quality, accuracy) and completeness of diagnosis information in CPRD Aurum are promising with respect to serious acute conditions that require medical attention. Evaluation of other data elements will provide additional insight into this new data resource and its utility for medical research.

Prognostic value of first-recorded breathlessness for future chronic respiratory and heart disease: a cohort study using a UK national primary care database

BACKGROUND

Breathlessness is a common presentation in primary care.

AIM

To assess the long-term risk of diagnosed chronic obstructive pulmonary disease (COPD), asthma, ischaemic heart disease (IHD), and early mortality in patients with undiagnosed breathlessness.

DESIGN AND SETTING

Matched cohort study using data from the UK Clinical Practice Research Datalink.

METHOD

Adults with first-recorded breathlessness between 1997 and 2010 and no prior diagnostic or prescription record for IHD or a respiratory disease ('exposed' cohort) were matched to individuals with no record of breathlessness ('unexposed' cohort). Analyses were adjusted for sociodemographic and comorbidity characteristics.

RESULTS

In total, 75 698 patients (the exposed cohort) were followed for a median of 6.1 years, and more than one-third subsequently received a diagnosis of COPD, asthma, or IHD. In those who remained undiagnosed after 6 months, there were increased long-term risks of all three diagnoses compared with those in the unexposed cohort. Adjusted hazard ratios for COPD ranged from 8.6 (95% confidence interval [CI] = 6.8 to 11.0) for >6-12 months after the index date to 2.8 (95% CI = 2.6 to 3.0) for >36 months after the index date; asthma, 11.7 (CI = 9.4 to 14.6) to 4.3 (CI = 3.9 to 4.6); and IHD, 3.0 (CI = 2.7 to 3.4) to 1.6 (CI = 1.5 to 1.7). Risk of a longer time to diagnosis remained higher in members of the exposed cohort who had no relevant prescription in the first 6 months; approximately half of all future diagnoses were made for such patients. Risk of early mortality (all cause and disease specific) was higher in members of the exposed cohort.

CONCLUSION

Breathlessness can be an indicator of developing COPD, asthma, and IHD, and is associated with early mortality. With careful assessment, appropriate intervention, and proactive follow-up and monitoring, there is the potential to improve identification at first presentation in primary care in those at high risk of future disease who present with this symptom.

Can the Use of Bayesian Analysis Methods Correct for Incompleteness in Electronic Health Records Diagnosis Data? Development of a Novel Method Using Simulated and Real-Life Clinical Data

Background: Patient health information is collected routinely in electronic health records (EHRs) and used for research purposes, however, many health conditions are known to be under-diagnosed or under-recorded in EHRs. In research, missing diagnoses result in under-ascertainment of true cases, which attenuates estimated associations between variables and results in a bias toward the null. Bayesian approaches allow the specification of prior information to the model, such as the likely rates of missingness in the data. This paper describes a Bayesian analysis approach which aimed to reduce attenuation of associations in EHR studies focussed on conditions characterized by under-diagnosis.

Methods: Study 1: We created synthetic data, produced to mimic structured EHR data where diagnoses were under-recorded. We fitted logistic regression (LR) models with and without Bayesian priors representing rates of misclassification in the data. We examined the LR parameters estimated by models with and without priors. Study 2: We used EHR data from UK primary care in a case-control design with dementia as the outcome. We fitted LR models examining risk factors for dementia, with and without generic prior information on misclassification rates. We examined LR parameters estimated by models with and without the priors, and estimated classification accuracy using Area Under the Receiver Operating Characteristic.

Results: Study 1: In synthetic data, estimates of LR parameters were much closer to the true parameter values when Bayesian priors were added to the model; with no priors, parameters were substantially attenuated by under-diagnosis. Study 2: The Bayesian approach ran well on real life clinic data from UK primary care, with the addition of prior information increasing LR parameter values in all cases. In multivariate regression models, Bayesian methods showed no improvement in classification accuracy over traditional LR.

Conclusions: The Bayesian approach showed promise but had implementation challenges in real clinical data: prior information on rates of misclassification was difficult to find. Our simple model made a number of assumptions, such as diagnoses being missing at random. Further development is needed to integrate the method into studies using real-life EHR data. Our findings nevertheless highlight the importance of developing methods to address missing diagnoses in EHR data.

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.

Temporal relationships between systemic lupus erythematosus and comorbidities

OBJECTIVE

To examine the burden of comorbidities prior to and after the diagnosis of SLE and its impact on mortality.

METHODS

We identified 1605 incident cases of SLE and 6284 matched controls from the UK primary care. The risks of comorbidities before (prevalence; odds ratios) and after SLE diagnosis (incidence; hazard ratios) and the impact of comorbidities at diagnosis on all-cause mortality were estimated.

RESULTS

At diagnosis, SLE was associated with adjusted odds ratios (95% CI) of 2.25 (1.97-2.56), 3.37 (2.49-4.57) and 3.54 (1.89-6.63) for a Charlson comorbidity index of 1-2, 3-4 and ≥5, respectively. Following diagnosis, SLE also associated with increased risk of developing any comorbidity with an adjusted hazard ratio (95% CI) of 1.30 (95% CI, 1.13-1.49). At diagnosis, SLE was associated with a greater risk of cancer, cardiovascular, renal, liver, rheumatological and neurological diseases as well as depression, anaemia and psoriasis. Risks of developing incident comorbidity in the categories of neoplasm, cardiovascular, genitourinary, metabolic/endocrine, gastrointestinal and hepatic diseases, chronic pulmonary diseases, musculoskeletal/connective tissue and neurological diseases were higher in SLE patients. People with SLE had higher mortality risk compared with controls, with adjusted hazard ratio of 1.91 (95% CI, 1.62-2.26); after further adjusting for comorbidities this reduced to 1.64 (1.37-1.97). Comorbidities at SLE diagnosis accounted for 27.6% of the apparent difference in mortality between SLE patients and matched controls.

CONCLUSION

People with SLE have increased risks of multiple comorbidities both prior to and after diagnosis and this contributes significantly to all-cause mortality.

Primary Care Prescriptions of Potentially Nephrotoxic Medications in Children with CKD

BACKGROUND AND OBJECTIVES

Pediatric CKD management focuses on limiting kidney injury, including avoiding nephrotoxic medications. Nephrotoxic medication prescription practices for children with CKD are unknown. Our objective was to determine the prevalence and rates of primary care prescriptions for potentially nephrotoxic medications in children with CKD versus without CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a retrospective, matched population-based cohort study of patients aged <18 years, registered at a general practice participating in the UK Clinical Practice Research Datalink (CPRD) from 1997 to 2017. Children with a clinical code indicating an incident diagnosis of CKD were matched 1:4 to patients without CKD on CKD diagnosis date, sex, age, CPRD practice, and number of general practitioner visits in the year before cohort entry. We calculated the prevalence and the rate of potentially nephrotoxic medication prescriptions throughout the follow-up period in patients with versus without CKD. Primary analyses included the following medication classes: aminoglycosides, antivirals, nonsteroidal anti-inflammatory drugs, salicylates, proton pump inhibitors, and immunomodulators. Secondary analyses used an expanded nephrotoxicity definition that also included, among others, angiotensin-converting enzyme inhibitors and angiotensin receptor blockers. Adjusted prescription rates were calculated using multivariable binomial regression.

RESULTS

From 1,535,816 eligible patients, we identified 1018 incident CKD and 4072 non-CKD matches (mean age, 9.8 years [range, 1.1-17.9 years]; 52% male; mean follow-up time, 3.3 years). Overall, 26% of patients with and 15% of patients without CKD were prescribed one or more potentially nephrotoxic medication during follow-up. The overall rate of nephrotoxic medication prescriptions was 71 (95% confidence interval [95% CI], 55 to 93) prescriptions per 100 person-years in patients with CKD and eight (95% CI, 7 to 9) prescriptions per 100 person-years in patients without CKD (adjusted rate ratio, 4.1; 95% CI, 2.7 to 6.1).

CONCLUSIONS

Potentially nephrotoxic medications are prescribed at high rates to children with CKD.

Incidence and Risk of Glucocorticoid-Associated Adverse Effects in Patients With Rheumatoid Arthritis

OBJECTIVE

Using the UK Clinical Practice Research Datalink, we examined the incidence of glucocorticoid (GC)-related serious adverse events (SAEs) in rheumatoid arthritis (RA) and non-RA patients and quantified the risk of SAEs in patients with RA.

METHODS

We matched incident patients with RA to an age- and sex-matched, non-RA comparison group of equal size. In a cohort analysis, we estimated incidence rates (IRs) and IR ratios (IRRs) for GC-related AEs (i.e., diabetes mellitus [DM], osteoporosis, fractures, glaucoma, hypertension, gastrointestinal [GI] perforation or bleeding, thrombotic stroke or myocardial infarction [MI], or death), stratified by GC use. We conducted a series of nested case-control analyses among patients with RA, evaluating the effects of increasing cumulative and average daily GC dose. Cases of each outcome were matched to controls for age, sex, and general practice. We calculated adjusted odds ratios (ORs) with 95% confidence intervals (95% CIs) for each outcome.

RESULTS

Patients with RA had a higher incidence for all investigated SAEs except glaucoma, compared to non-RA patients. IRRs were greater in those patients prescribed a GC than in those without. In patients with RA, GCs were associated with an elevated risk of DM (adjusted OR 1.33 [95% CI 1.14-1.56]), osteoporosis (adjusted OR 1.41 [95% CI 1.25-1.59]), thrombotic stroke or MI (adjusted OR 1.28 [95% CI 1.07-1.52]), serious infection (adjusted OR 1.28 [95% CI 1.11-1.48]), and death (adjusted OR 1.33 [95% CI 1.19-1.48]). There was a trend of increasing risk with increasing cumulative and average daily GC dose for all outcomes other than glaucoma, hypertension, and GI perforations or bleeding (P < 0.05).

CONCLUSION

Patients with RA had an increased incidence of GC-related AEs. Increasing cumulative and average daily GC doses were found to be associated with an increasing risk of developing an AE.

Atopic Eczema in Adulthood and Risk of Depression and Anxiety: A Population-Based Cohort Study

BACKGROUND

Atopic eczema is a common and debilitating condition associated with depression and anxiety, but the nature of this association remains unclear.

OBJECTIVE

To explore the temporal relationship between atopic eczema and new depression/anxiety.

METHODS

This matched cohort study used routinely collected data from the UK Clinical Practice Research Datalink, linked to hospital admissions data. We identified adults with atopic eczema (1998-2016) using a validated algorithm, and up to 5 individuals without atopic eczema matched on date of diagnosis, age, sex, and general practice. We estimated the hazard ratio (HR) for new depression/anxiety using stratified Cox regression to account for age, sex, calendar period, Index of Multiple Deprivation, glucocorticoid treatment, obesity, smoking, and harmful alcohol use.

RESULTS

We identified 526,808 adults with atopic eczema who were matched to 2,569,030 without. Atopic eczema was associated with increased incidence of new depression (HR, 1.14; 99% CI, 1.12-1.16) and anxiety (HR, 1.17; 99% CI, 1.14-1.19). We observed a stronger effect of atopic eczema on depression with increasing atopic eczema severity (HR [99% CI] compared with no atopic eczema: mild, 1.10 [1.08-1.13]; moderate, 1.19 [1.15-1.23]; and severe, 1.26 [1.17-1.37]). A dose-response association, however, was less apparent for new anxiety diagnosis (HR [99% CI] compared with no atopic eczema: mild, 1.14 [1.11-1.18]; moderate, 1.21 [1.17-1.26]; and severe, 1.15; [1.05-1.25]).

CONCLUSIONS

Adults with atopic eczema are more likely to develop new depression and anxiety. For depression, we observed a dose-response relationship with atopic eczema severity.

Diabetes, metformin and cancer risk in myotonic dystrophy type I

Myotonic dystrophy type I (DM1) is an autosomal dominant multisystem disorder characterized by myotonia and muscle weakness. Type 2 diabetes (T2D) and cancer have been shown to be part of the DM1 phenotype. Metformin, a well-established agent for the management of T2D, is thought to have cancer-preventive effects in the general population. In our study, we aimed to assess the association between T2D, metformin use and the risk of cancer in DM1 patients. We identified a cohort of 913 DM1 patients and an age-, sex- and clinic-matched cohort of 12,318 DM1-free controls from the UK Clinical Practice Research Datalink, a large primary care records database. We used Cox regression models to assess cancer risk in T2D patients who were metformin users or nonusers compared to patients without T2D. Separate analyses were conducted for DM1 patients and controls. T2D was more prevalent in DM1 than in controls (8% vs. 3%, p < 0.0001). DM1 patients with T2D, compared to those without T2D, were more likely to develop cancer (hazard ratio [HR] = 3.60, 95% confidence interval [CI] = 1.18-10.97; p = 0.02), but not if they were treated with metformin (HR = 0.43, 95% CI = 0.06-3.35; p = 0.42). Among controls, we observed no significant associations between T2D and cancer risk in either users or nonusers of Metformin (HR = 1.28, 95% CI = 0.91-1.79; p = 0.16 and HR = 1.13, 95% CI = 0.72-1.79; p = 0.59, respectively). These results show an association between T2D and cancer risk in DM1 patients and may provide new insights into the possible benefits of Metformin use in DM1.

Autoimmune diseases and immunosuppressive therapy in relation to the risk of glioma

Effectors from the immune system can modulate the course and possibly the early development of gliomas. We, therefore, hypothesized that autoimmune diseases associated with increased immune‐surveillance may also modulate the risk of human glioma. To test this hypothesis, we used data from the well‐validated Clinical Practice Research Datalink (CPRD) GOLD from the UK to analyze the association of immune‐related disorders or use of immunosuppressive drugs and the risk of glioma. We identified 3112 incident glioma cases diagnosed between 1995 and 2017. We randomly selected up to 10 controls, matching them to glioma cases on age, sex, index date, general practice, and number of years of active history in the database prior to the index date. We performed conditional logistic regression analyses to estimate Odds Ratios (ORs) of glioma among those exposed to allergies, autoimmune diseases, and immunosuppressive drugs. Overall, we found no materially altered association between a history of any autoimmune disease (OR 0.98, 95% CI 0.86‐1.11), allergy (OR 0.97, 95% CI 0.89‐1.05), or use of immunosuppressive drugs and the risk of glioma. However, subgroup analyses among younger patients found a statistically significant increased risk of glioma in patients with a history of inflammatory bowel disease (IBD) (OR 2.59, 95% CI 1.31‐5.12). There was also an inverse association between asthma and risk of glioma in patients with longer survival (OR 0.73, 95% CI 0.58‐0.91) and between long‐term duration diabetes and risk of glioma (OR 0.71, 95% CI 0.53‐0.96).

Primary care risk stratification in COPD using routinely collected data: a secondary data analysis

Most clinical contacts with chronic obstructive pulmonary disease (COPD) patients take place in primary care, presenting opportunity for proactive clinical management. Electronic health records could be used to risk stratify diagnosed patients in this setting, but may be limited by poor data quality or completeness. We developed a risk stratification database algorithm using the DOSE index (Dyspnoea, Obstruction, Smoking and Exacerbation) with routinely collected primary care data, aiming to calculate up to three repeated risk scores per patient over five years, each separated by at least one year. Among 10,393 patients with diagnosed COPD, sufficient primary care data were present to calculate at least one risk score for 77.4%, and the maximum of three risk scores for 50.6%. Linked secondary care data revealed primary care under-recording of hospital exacerbations, which translated to a slight, non-significant cohort average risk score reduction, and an understated risk group allocation for less than 1% of patients. Algorithmic calculation of the DOSE index is possible using primary care data, and appears robust to the absence of linked secondary care data, if unavailable. The DOSE index appears a simple and practical means of incorporating risk stratification into the routine primary care of COPD patients, but further research is needed to evaluate its clinical utility in this setting. Although secondary analysis of routinely collected primary care data could benefit clinicians, patients and the health system, standardised data collection and improved data quality and completeness are also needed.

Risk of hand osteoarthritis in new users of hormone replacement therapy: A nested case-control analysis

OBJECTIVE

To estimate the risk of hand osteoarthritis (HOA) associated with hormone replacement therapy (HRT).

METHODS

We conducted a nested case-control study using data from the UKbased Clinical Practice Research Datalink (1998-2017). In the study inception cohort comprised women at age 45. We matched women with incident HOA during follow-up (cases) to osteoarthritisfree controls on age and calendar date (index date, ID), in a ratio of 1:4. We applied conditional logistic regression to calculate odds ratios (OR) with 95 % confidence intervals (CI) of HOA associated with new HRT use compared with non-use overall, and for women with recorded menopause we calculated separate ORs according to the time between menopause and HRT initiation (current users), and the time between HRT cessation and the ID (past users), versus non-users.

RESULTS

There were 3440 cases and 13,760 controls (mean age: 50.9 ± 4.1 years). We observed an adjusted OR (aOR) of HOA of 1.32 (95 % CI 1.17-1.48) in HRT users (versus nonusers), which attenuated to 0.98 (95 % CI 0.85-1.14) in women with recorded menopause. Current users (versus nonusers) who initiated HRT 3 months before or after menopause had an aOR of 0.72 (95 % CI 0.55-0.96), while aORs increased with later HRT initiation. Among past users (versus non-users), we observed an aOR of 1.25 (95 % CI 0.86-1.81) when HRT use was stopped ≤18 months before the ID, approaching the null with increasing duration between HRT cessation and the ID.

CONCLUSION

Current HRT use was associated with a decreased risk of HOA if initiated around menopause, but the risk reduction disappeared after HRT cessation.

Increased Prevalence of Polyneuropathy in Parkinson's Disease Patients: An Observational Study

BACKGROUND

The independent contribution of levodopa exposure and Parkinson's disease (PD) to the risk of polyneuropathy is not established.

OBJECTIVE

This study investigated whether patients with newly diagnosed PD without previous exposure to antiparkinsonian drugs have higher prevalence of polyneuropathy than the general population.

METHODS

Using the UK General Practice Research Database, presence of polyneuropathy in the previous 3 years was assessed.

RESULTS

Of 5089 PD patients and 19,897 controls, polyneuropathy was confirmed in 15 PD patients (0.29% ) and 24 controls (0.12% ). Polyneuropathy prevalence was 2.4-fold higher in PD patients than controls.

CONCLUSIONS

In this observational study, PD patients had a higher prevalence of preexisting polyneuropathy that cannot be explained by adverse effects of antiparkinsonian drugs.

Inhaled corticosteroids in COPD and onset of type 2 diabetes and osteoporosis: matched cohort study

Some studies suggest an association between onset and/or poor control of type 2 diabetes mellitus and inhaled corticosteroid (ICS) therapy for chronic obstructive pulmonary disease (COPD), and also between increased fracture risk and ICS therapy; however, study results are contradictory and these associations remain tentative and incompletely characterized. This matched cohort study used two large UK databases (1983–2016) to study patients (≥ 40 years old) initiating ICS or long-acting bronchodilator (LABD) for COPD from 1990–2015 in three study cohorts designed to assess the relation between ICS treatment and (1) diabetes onset (N = 17,970), (2) diabetes progression (N = 804), and (3) osteoporosis onset (N = 19,898). Patients had ≥ 1-year baseline and ≥ 2-year outcome data. Matching was via combined direct matching and propensity scores. Conditional proportional hazards regression, adjusting for residual confounding after matching, was used to compare ICS vs. LABD and to model ICS exposures. Median follow-up was 3.7–5.6 years/treatment group. For patients prescribed ICS, compared with LABD, the risk of diabetes onset was significantly increased (adjusted hazard ratio 1.27; 95% CI, 1.07–1.50), with overall no increase in risk of diabetes progression (adjusted hazard ratio 1.04; 0.87–1.25) or osteoporosis onset (adjusted hazard ratio 1.13; 0.93–1.39). However, the risks of diabetes onset, diabetes progression, and osteoporosis onset were all significantly increased, with evident dose–response relationships for all three outcomes, at mean ICS exposures of 500 µg/day or greater (vs. < 250 µg/day, fluticasone propionate–equivalent). Long-term ICS therapy for COPD at mean daily exposure of ≥ 500 µg is associated with an increased risk of diabetes, diabetes progression, and osteoporosis.

Mortality risk in atrial fibrillation: the role of aspirin, vitamin K and non-vitamin K antagonists

Background As an alternative to vitamin K antagonist and low-dose aspirin (< 325 mg), non-vitamin K oral anticoagulants are available for the prevention of stroke in patients with atrial fibrillation. However, the mortality risk associated with these drugs in daily practice remains unclear. Objective To evaluate the risk of all-cause mortality associated with non-Vitamin K antagonist oral anticoagulants, vitamin K antagonists or aspirin in patients with atrial fibrillation. Setting A cohort study conducted among atrial fibrillation patients using the UK Clinical Practice Research Datalink (March 2008-October 2014). Method New users of vitamin K antagonists, non vitamin K oral anticoagulants, low-dose aspirin, or combination therapy were followed from the date of first prescription to the date of death, as recorded in the UK datalink. Cox proportional hazard models estimated the hazard ratio (HR) of all-cause mortality for users of NOACs, aspirin, or combination use, as compared to vitamin K antagonist. Analyses were adjusted for confounders. Main outcome measure All-cause mortality. Results We identified 31,497 patients. Non vitamin K antocoagulant use (adjusted HR [aHR] = 1.42; 95% Confidence Interval [CI] 1.18-1.71) and aspirin use (aHR = 1.64; 95% CI 1.57-1.77) were both significantly associated with a higher mortality risk than use of vitamin K antagonists. The higher mortality risk for the non vitamin K anticoagulant use was observed in men (aHR = 1.72; 95% CI 1.25-2.36), but not in women (aHR = 1.28; 95% CI 0.92-1.79. Compared to  vitamin K antagonists, mortality risk associated with the non vitamin K anticoagulants and aspirin use was significantly increased in patients with higher stroke risk (CHA₂DS₂-VASc > 2). Conclusion Non vitamin K oral anticoagulants are  associated with a higher risk on all-cause mortality, particularly in men and in patients with higher stroke risk.

Sulfonylureas as initial treatment for type 2 diabetes and the risk of adverse cardiovascular events: A population-based cohort study

AIMS

Sulfonylureas are recommended as second-line treatment in the management of type 2 diabetes. However, they are still commonly used also as first-line treatment instead of metformin. Given the controversial cardiovascular safety of sulfonylureas, we aimed to determine if their use as first-line treatment is associated with adverse cardiovascular events among patients with newly treated type 2 diabetes compared with metformin.

METHODS

We conducted a population-based cohort study of patients with newly treated type 2 diabetes using the UK's Clinical Practice Research Datalink. Initiators of metformin and sulfonylurea monotherapy were matched on high-dimensional propensity score, and Cox proportional hazards models were used to compare the rate of cardiovascular events (myocardial infarction, ischaemic stroke, cardiovascular death, and all-cause mortality) with sulfonylureas vs metformin.

RESULTS

Our cohort included 94 750 patients initiating treatment for type 2 diabetes, 17 612 on a sulfonylurea and 77 138 on metformin. After matching, sulfonylurea monotherapy, compared with metformin monotherapy, was not associated with an increased risk of myocardial infarction (hazard ratio [HR]: 1.04, 95% confidence interval [CI]: 0.85-1.25) but was associated with increased risks of ischaemic stroke (HR: 1.25, 95% CI: 1.002-1.56), cardiovascular death (HR: 1.25, 95% CI: 1.06-1.47), and all-cause mortality (HR: 1.60, 95% CI: 1.45-1.76). This represents an additional 2.0 ischaemic strokes, 3.5 cardiovascular deaths, and 21.4 all-cause deaths per 1,000 patients per year with sulfonylureas.

CONCLUSIONS

Initiating treatment of type 2 diabetes with a sulfonylurea rather than metformin is associated with higher rates of ischaemic stroke, cardiovascular death, and all-cause mortality.

A study on the epidemiology of tinnitus in the United Kingdom

PURPOSE

Subjective tinnitus is a common symptom with potentially negative impact on quality of life. More research is required to gain a deeper understanding of the disease and its clinical presentation. To estimate the incidence of tinnitus and to describe patient-related characteristics such as lifestyle factors and comorbidities.

PATIENTS AND METHODS

Using the Clinical Practice Research Datalink, we calculated incidence rates of first-time diagnosed tinnitus in an adult population between 2000 and 2016. We stratified incidence rates by sex, age, and year of diagnosis. Additionally, we performed a 1:1 matched case-control study comparing body mass index, lifestyle factors and selected comorbidities between patients with incident tinnitus and tinnitus-free controls.

RESULTS

We identified 109 783 adults with a first-time diagnosis of tinnitus between 2000 and 2016, yielding an overall age-standardized incidence rate of 25.0 new tinnitus cases per 10,000 person-years (95% CI: 24.6-25.5). There was a steady increase in tinnitus incidence throughout the study period. Approximately 80% of tinnitus cases were diagnosed at age 40 years or older. We observed the highest incidence rate in individuals aged 60-69 years (41.2 per 10,000 person-years, 95% CI: 40.7-41.7). Smokers and alcohol drinkers were at lower risk of being diagnosed with tinnitus compared with non-smokers and non-drinkers, respectively. The occurrence of tinnitus was strongly associated with a recent diagnosis of several otological and vestibular disorders as well as head and neck disorders.

CONCLUSION

The present observational study found an increasing incidence of tinnitus over time, emphasizing the continuously growing health burden. The findings on patient characteristics, lifestyle factors, and selected comorbidities contribute to a better understanding of risk factors for tinnitus.

Cardiovascular and Cerebrovascular Safety of Testosterone Replacement Therapy Among Aging Men with Low Testosterone Levels: A Cohort Study

PURPOSE

We assessed the risk of ischemic stroke, transient ischemic attack, and myocardial infarction associated with testosterone replacement therapy (TRT) among aging men with low testosterone levels.

METHODS

Using the UK Clinical Practice Research Datalink, we formed a cohort of men aged 45 years or older with low testosterone levels and no evidence of hypogonadotropic or testicular disease, between 1995 and 2017. Hazard ratios (HRs) and 95% confidence intervals (CIs) of a composite of ischemic stroke/transient ischemic attack and myocardial infarction were estimated using time-dependent Cox proportional hazards models, comparing current use of TRT with nonuse.

RESULTS

The cohort included 15,401 men. During 71,541 person-years of follow-up, 850 patients experienced an ischemic stroke/transient ischemic attack/myocardial infarction (crude incidence rate 1.19 [95% confidence interval (CI), 1.11-1.27] per 100 persons per year). Compared with nonuse, current use of TRT was associated with an increased risk of the composite outcome (HR 1.21; 95% CI, 1.00-1.46). This risk was highest in the first 6 months to 2 years of continuous TRT use (HR 1.35; 95% CI, 1.01-1.79), as well as among men aged 45-59 years (HR 1.44; 95% CI, 1.07-1.92).

CONCLUSIONS

TRT may increase the risk of cardiovascular events in aging men with low testosterone levels, particularly in the first 2 years of use. In the absence of identifiable causes of hypogonadism, TRT should be initiated with caution among aging men with low testosterone levels.