Hip/femur fractures associated with the use of benzodiazepines (anxiolytics, hypnotics and related drugs): a methodological approach to assess consistencies across databases from the PROTECT-EU project

Evolution of benzodiazepine receptor agonist prescriptions in general practice: A registry-based study

Background

Contrary to most European guidelines, benzodiazepine receptor agonists (BZRA) are often used continuously at a low dosage, being the most common form of long-term use. In Belgium, BZRA use is monitored by analyzing self-report data about medication use in the last 24 h. This method provides insufficient insight into the terms of use of these psychoactive drugs.

Aim

To describe trends in BZRA prescribing in Flanders, Belgium, between 2000 and 2019.

Design and setting

Population-based trend analysis and a case-control study for the year 2019 were done with data from a morbidity registry in general practice.

Methods

Repeated cross-sectional and joinpoint regression analyses revealed trends in sex- and age-standardized prescription rates among adult patients (18+).

Results

Overall, BZRA prescriptions increased. The highest overall increase was found among male patients 18-44 years old, with an average annual percentage change of 2.5 (95% CI: 0.9, 4.3). Among 65+ female patients, a decrease was found since 2006, with an annual percentage change of -0.7 (95% CI: -1.3, -0.1). In 2019, 12% of registered patients received minimally one prescription, long-term use was observed in 5%, back pain was the most common morbidity significantly associated with a rise in BZRA prescriptions, and zolpidem was the most prescribed BZRA (22%).

Conclusion

Despite some statistically significant decreasing trends, an overall increase in BZRA prescriptions was observed throughout the 19-year study period, especially among long-term users of 18-44 years and 65-plus. Zolpidem became the most prescribed BZRA and warrants more attention.

Comparative safety of chronic versus intermittent benzodiazepine prescribing in older adults: A population-based cohort study

BACKGROUND

Benzodiazepine treatment recommendations for older adults differ markedly between guidelines, especially their advice on the acceptability of long-term use.

AIMS

Using population-based data we compared risks associated with chronic versus intermittent benzodiazepine usage in older adults. The primary outcome was falls resulting in hospital/emergency department visits.

METHODS

We undertook a retrospective population-based cohort study using linked healthcare databases in adults aged ⩾ 66 years in Ontario, Canada, with a first prescription for benzodiazepines. Chronic and intermittent benzodiazepine users, based on the 180 days from index prescription, were matched (1:2 ratio) by sex, age and propensity score, then followed for up to 360 days. Hazard ratios (HRs) for outcomes were calculated from Cox regression models.

RESULTS

A total of 57,041 chronic and 113,839 matched intermittent users were included. Hospitalization/emergency department visits for falls occurred during follow up in 4.6% chronic versus 3.2% intermittent users (HR = 1.13, 95% confidence interval (CI): 1.08 to 1.19; p < 0.0001). There were significant excess risks in chronic users for most secondary outcomes: hip fractures, hospitalizations/emergency department visits, long-term care admission and death, but not wrist fractures. Adjustment for benzodiazepine dosage had minimal impact on HRs.

CONCLUSION

Our study demonstrates evidence of significant excess risks associated with chronic benzodiazepine use compared to intermittent use. The excess risks may inform decision-making by older adults and clinicians about whether short- or long-term benzodiazepine use is a reasonable option for symptom management.

Risk of ischaemic stroke among new users of glucosamine and chondroitin sulphate: a nested case–control study

Background:

Several studies have reported that the use of chondroitin sulphate (CS) and glucosamine may reduce the risk of acute myocardial infarction. Although it is thought that this potential benefit could be extended to ischaemic stroke (IS), the evidence is scarce.

Objective:

To test the hypothesis that the use of prescription glucosamine or CS reduces the risk of IS.

Design:

Case–control study nested in an open cohort.

Methods:

Patients aged 40–99 years registered in a Spanish primary healthcare database (BIFAP) during the 2002–2015 study period. From this cohort, we identified incident cases of IS, applying a case-finding algorithm and specific validation procedures, and randomly sampled five controls per case, individually matched with cases by exact age, gender and index date. Adjusted odds ratios (AORs) and 95% confidence interval (CI) were computed through a conditional logistic regression. Only new users of glucosamine or CS were considered.

Results:

A total of 13,952 incident cases of IS and 69,199 controls were included. Of them, 106 cases (0.76%) and 803 controls (1.16%) were current users of glucosamine or CS at index date, yielding an AOR of 0.66 (95% CI: 0.54–0.82) (for glucosamine, AOR: 0.55; 95% CI: 0.39–0.77; and for CS, AOR: 0.77; 95% CI: 0.60–0.99). The reduced risk among current users was observed in both sexes (men, AOR: 0.69; 95% CI: 0.49–0.98; women, AOR: 0.65; 95% CI: 0.50–0.85), in individuals above and below 70 years of age (AOR: 0.69; 95% CI: 0.53–0.89 and AOR: 0.59; 95% CI: 0.41–0.85, respectively), in individuals with vascular risk factors (AOR: 0.53; 95% CI: 0.39–0.74) and among current/recent users of nonsteroidal anti-inflammatory drugs (NSAIDs) (AOR: 0.71; 95% CI: 0.55–0.92). Regarding duration, the reduced risk was observed in short-term users (<365 days, AOR: 0.61; 95% CI: 0.48–0.78) while faded and became nonsignificant in long-term users (>364 days AOR: 0.86; 95% CI: 0.57–1.31).

Conclusions:

Our results support a protective effect of prescription CS and glucosamine in IS, which was observed even in patients at vascular risk.

Mini abstract

Our aim was to analyse whether the use of glucosamine or chondroitin sulphate (CS) reduces the risk of ischaemic stroke (IS). We detected a significant decrease.

Effect of regulatory interventions on agomelatine use in Spain: A multiple intervention time-series analysis in a nationwide electronic healthcare record database

BACKGROUND

Liver injury is an important identified risk for agomelatine and several measures were put in place to prevent and minimize such risk. The study aims to assess the impact of four interventions on the incidence of agomelatine use, particularly among patients aged ≥75 in Spain between 2011 and 2018.

METHODS

Quasi-experimental interrupted time-series analysis to examine data from a nationwide electronic healthcare record database (BIFAP). Quarterly cumulative incidence of agomelatine use per 100 000 patients was calculated and the impact of four regulatory interventions was quantified.

RESULTS

The incidence of agomelatine use decreased by 85% and 87% from first quarter 2011 to last quarter 2018 in patients below and above 75 years old, respectively. Regulatory actions taken were not associated with an immediate and significant falling level of use or slope. The incidence was less than expected 6 months after the first and third intervention for patients below and above 75 years old, and more than expected after the second and fourth intervention for both populations, though these analyses were underpowered to observe significant results. The downward trend became less pronounced, reaching a residual level of use, which remained stable in the last segment of the study period.

CONCLUSION

New users of agomelatine decreased throughout the study period, starting before interventions took place. The effect of specific interventions might be masked by the progressive decrease tendency, constant over the study period. The effects of external factors that might overlap, unintended consequences, and issues concerning statistical modeling in situations where rates are already falling, should be considered when interpreting the results.

Risk of acute myocardial infarction among new users of chondroitin sulfate: A nested case-control study

Objective

To test the hypothesis that the use of chondroitin sulfate (CS) or glucosamine reduces the risk of acute myocardial infarction (AMI).

Design

Case-control study nested in a primary cohort of patients aged 40 to 99 years, using the database BIFAP during the 2002–2015 study period. From this cohort, we identified incident cases of AMI and randomly selected five controls per case, matched by exact age, gender, and index date. Adjusted odds ratios (AOR) and 95% confidence interval (CI) were computed through a conditional logistic regression. Only new users of CS or glucosamine were considered.

Results

A total of 23,585 incident cases of AMI and 117,405 controls were included. Of them, 89 cases (0.38%) and 757 controls (0.64%) were current users of CS at index date, yielding an AOR of 0.57 (95%CI: 0.46–0.72). The reduced risk among current users was observed in both short-term (<365 days, AOR = 0.58; 95%CI: 0.45–0.75) and long-term users (>364 days AOR = 0.56; 95%CI:0.36–0.87), in both sexes (men, AOR = 0.52; 95%CI:0.38–0.70; women, AOR = 0.65; 95%CI:0.46–0.91), in individuals over or under 70 years of age (AOR = 0.54; 95%CI:0.38–0.77, and AOR = 0.61; 95%CI:0.45–0.82, respectively) and in individuals at intermediate (AOR = 0.65; 95%CI:0.48–0.91) and high cardiovascular risk (AOR = 0.48; 95%CI:0.27–0.83), but not in those at low risk (AOR = 1.11; 95%CI:0.48–2.56). In contrast, the current use of glucosamine was not associated with either increased or decreased risk of AMI (AOR = 0.86; 95%CI:0.66–1.08).

Conclusions

Our results support a cardioprotective effect of CS, while glucosamine seems to be neutral. The protection was remarkable among subgroups at high cardiovascular risk.

Benzodiazepine Treatment and Fracture Risk in Young Persons With Anxiety Disorders

BACKGROUND

Benzodiazepines are commonly prescribed to treat anxiety disorders and have been associated with falls and fractures in older adults. It is unknown whether benzodiazepines increase fracture risk in youth. We examined whether youth with anxiety disorders initiating benzodiazepine treatment have an increased risk of fractures compared with youth initiating selective serotonin reuptake inhibitors (SSRIs).

METHODS

We used claims from commercially insured children (6-17 years) and young adults (18-24) with a recent anxiety disorder diagnosis, initiating benzodiazepines or SSRIs (2008-2016). Youth were followed until fracture, treatment discontinuation or switching, disenrollment, 3 months, or December 31, 2016. The primary end point was diagnostic codes for upper and lower limb fractures. Incident fracture rates, incident rate ratios (IRRs), and incident rate differences (IRDs) were estimated with propensity score inverse probability of treatment weighting.

RESULTS

The cohort included 120 715 children and 179 768 young adults. In children, crude fracture rates during treatment were 33.1 per 1000 person-years (PYs) for benzodiazepine initiators and 25.1 per 1000 PYs for SSRI initiators. Adjusted IRR and IRD were 1.53 (95% confidence interval [CI]: 0.94-2.50) and 13.4 per 1000 PYs. Risk was heightened in children initiating long-acting benzodiazepines versus SSRIs (adjusted IRR = 2.30 [95% CI: 1.08-4.91]). Fracture rates were lower in young adults, with minimal differences between treatments (adjusted IRR = 0.85 [95% CI: 0.57-1.27]; adjusted IRD = -1.3 per 1000 PYs).

CONCLUSIONS

An increased rate of fractures in children, but not young adults, with anxiety disorders initiating benzodiazepine treatment compared to SSRI treatment suggests a need for increased caution in the weeks after benzodiazepine initiation in children.

Evidence for deprescription in primary care through an umbrella review

BACKGROUND

There is a high prevalence of potentially inappropriate prescriptions in primary care. This is associated with more frequent adverse events, lower quality of life and more frequent visits to hospital accident & emergency departments. The aim of the present study is to summarise available evidence on the effectiveness of deprescription interventions in primary care, and to describe the barriers and enablers of the process from the point of view of patients and healthcare professionals.

METHODS

We designed an umbrella review which includes nine systematic reviews. More than 50% of included studies were performed with adults in primary care. Two reviewers independently performed data extraction and analysis.

RESULTS

In considering studies of the effectiveness of interventions, it can be observed that the educational component of deprescription procedures is a key factor, whilst procedures tailored towards the patient's situation offer better results. With regards to studies involving healthcare professionals, the main explored areas were the balance between risks and benefits, and the need to improve communication with patients as well as other colleagues involved in patient care. Amongst the identified barriers we found lack of time, inability to access all information, being stuck in a routine, resistance to change and a lack of willingness to question the prescription decisions made by healthcare colleagues. With regards to patients, it is clear that they have worries and doubts. In order to overcome these issues, a good relationship with healthcare professionals and receipt of their support is required during the process.

CONCLUSIONS

Optimizing medication through targeted deprescribing is an important part of managing chronic conditions, avoiding adverse effects and improving outcomes. The majority of deprescription interventions in primary care are effective. Good communication between healthcare professionals is a key element for success in the deprescription process.

Base de Datos para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP): A data resource for pharmacoepidemiology in Spain

PURPOSE

Base de Datos para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP) is a population based database administered by the AEMPS (Spanish Agency for Medicines) of longitudinal electronic medical records (EMR) of patients attended in primary care. Its main purpose is to serve as source of information for independent studies on drug safety and support of medicines regulation activities. This article aim is to describe the characteristics of BIFAP, how to access the database and a summary of its potential for research.

METHODS

Health problems are registered by primary care physicians as episodes of care and include socio-demographic data, results of diagnostic procedures, lifestyle data, general data, and interventions. A proportion of data on hospitalizations and specialist care are currently available through linkage with other data sources. EMRs of the Spanish healthcare system are provided by the regional administrations. Specific data extraction and standardization processes are performed.

RESULTS

BIFAP includes data from 12 million patients starting in 2001 and updated annually. Validation of drug and diagnosis definitions has been ascertained. Participation in international collaborative projects and a number of articles in peer reviewed journals reflect its contribution to the knowledge of the risks associated with medicines and drug utilization patterns.

CONCLUSIONS

BIFAP is a useful tool for generating scientific evidence on medicines related issues, helping regulatory decision making in Europe. The main strengths of BIFAP are related to large sample size, population-based, longitudinal nature and annual update of data. BIFAP shares common challenges with similar data sources including accurate and efficient identification of health outcomes and of treatment exposure.

Differential effects of antidepressant subgroups on risk of acute myocardial infarction: A nested case-control study

The primary objective of this study was to investigate the association between antidepressants use and the risk of acute myocardial infarction (AMI).

METHODS

We conducted a nested case-control study using a primary care database over the period 2002-2015. From a cohort of patients aged 40-99 years, we identified incident AMI cases and randomly selected 5 controls per case, matched to cases for exact age, sex and index date. Exposure to antidepressants were categorised as current, recent, past and nonusers. Adjusted odds ratio (AOR) and 95% confidence interval (CI) were computed using conditional logistic regression to assess the association between the current use of different antidepressants subgroups and AMI as compared to nonuse. Dose and duration effects were explored.

RESULTS

Totals of 24 155 incident AMI cases and 120 775 controls were included. The current use of antidepressants as a group was associated with a reduced risk (AOR = 0.86; 95% CI: 0.81-0.91), but mainly driven by selective serotonin reuptake inhibitors (AOR = 0.86; 95% CI:0.81-0.93). A reduced risk was also observed with trazodone (AOR = 0.76;95% CI: 0.64-0.91), and clomipramine (AOR = 0.62; 95% CI: 0.40-0.96), whereas no significant effect was observed with other antidepressants. A duration-dependent effect was suggested for selective serotonin reuptake inhibitors, trazodone and clomipramine, while there was no clear dose-dependency.

CONCLUSION

This study suggests that current use of antidepressants interfering selectively with the reuptake of serotonin, and those antagonizing the 5-HT_2A receptor, are associated with a decrease in AMI risk and should be the antidepressants of choice in patients at cardiovascular risk.

Analytic and Data Sharing Options in Real-World Multidatabase Studies of Comparative Effectiveness and Safety of Medical Products

A wide range of analytic and data sharing options are available in nonexperimental multidatabase studies designed to assess the real-world benefits and risks of medical products. Researchers often consider six scientific domains when choosing among these options-study design, exposure type, outcome type, covariate summarization technique, covariate adjustment method, and data sharing approach. This article reviews available analytic and data sharing options and discusses key scientific and practical considerations when choosing among these options in multidatabase studies of comparative effectiveness and safety of medical products. The scientific considerations must be balanced against what the data-contributing sites are able or willing to share. While pooling of person-level data sets remains the most familiar and analytically flexible approach, newer analytic and data sharing approaches that share less granular summary-level information may be equally valid and preferred in some multidatabase studies, especially when sharing of person-level data is challenging or infeasible.

Impact of pre-exposure time bias in self-controlled case series when the event conditions the exposure: Hip/femur fracture and use of benzodiazepines as a case study

BACKGROUND

In self-controlled case series (SCCS), the event should not condition the probability of subsequent exposure. If this assumption is not met, an important bias could take place. The association of hip/femur fracture (HFF) and use of benzodiazepines (BDZ) has a bidirectional causal relationship and can serve as case study to investigate the impact of this methodological issue.

OBJECTIVES

To assess the magnitude of bias introduced in a SCCS when HFF conditions the posterior exposure to BDZ and explore ways to correct it.

METHODS

Four thousand four hundred fifty cases of HFF who had at least one BZD prescription were selected from the primary care health record database BIFAP. Exposure to BZD was divided into non-use, current, recent, and past use. Conditional Poisson regression was used to estimate incidence rate ratios (IRRs) of HFF among current vs non-use/past, adjusted for age. To investigate possible event-exposure dependence, a pre-exposure time of different lengths (15, 30, and 60 days) was excluded from the reference category to evaluate the IRR.

RESULTS

IRR of HHF for current use was 0.79 (0.72-0.86); removing 30 days, IRR was 1.43 (1.31-1.57). Removing 15 days, IRR was 1.29 (1.18-1.41), and removing 60 days, IRR was 1.56 (1.42-1.72). A pre-exposure period up to 182 days was necessary to remove such effect giving an IRR of 1.64 (1.48-1.81).

CONCLUSIONS

HFF remarkably conditioned the use of BDZs resulting in seriously biased IRRs when this association was studied through a SCCS design. The use of pre-exposure periods of different lengths helped to correct this error.

Risk of Myocardial Infarction Among New Users of Calcium Supplements Alone or Combined With Vitamin D: A Population-Based Case-Control Study

A population‐based case‐control study was conducted to evaluate the risk of acute myocardial infarction among new users of calcium supplements either in monotherapy (CaM) or in combination with vitamin D (CaD). A total of 23,025 cases and 114,851 controls randomly sampled from the underlying cohort and matched with cases by age, sex, and index date were included. New users of CaM and CaD were categorized as current users, recent users, past users, and nonusers. We computed adjusted odds ratios (AORs) and their 95% confidence intervals (CIs) among current users as compared with nonusers through a conditional logistic regression. No increased risk was associated with CaM overall (59 cases (0.26%) and 273 controls (0.24%); AOR = 0.80; 95% CI 0.59–1.09), nor was it found in any of the conditions examined. Instead, the use of CaD was associated with a decreased risk (275 cases (1.19%) and 1,160 controls (1.45%); AOR = 0.78; 95% CI 0.67–0.90), dose and duration‐dependent, and particularly evident in patients with a high cardiovascular risk (AOR = 0.59; 95% CI 0.43–0.81).

Clinical Infections by Herpesviruses in Patients Treated with Valproic Acid: A Nested Case-Control Study in the Spanish Primary Care Database, BIFAP

The objective of this study is to evaluate the risk of clinical infections by herpesviruses in patients exposed to valproic acid (VPA). We performed a case-control study nested in a primary cohort selected from the Spanish primary care population-based research database BIFAP (Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria) over the period 2001–2015. The events of interest were those diseases caused by any herpesviruses known to infect humans. For each case, up to 10 controls per case matched by age, gender, and calendar date were randomly selected. A conditional logistic regression was used to compute adjusted odds ratios (OR) and their 95% confidence intervals (95% CI). Current use of VPA was associated with a trend towards a reduced risk of clinical infections by herpesviruses as compared with non-users (OR 0.84; CI 95% 0.7–1.0; p = 0.057). Among current users, a trend to a decreased risk with treatment durations longer than 90 days was also observed. The results show a trend to a reduced risk of clinical infection by herpesviruses in patients exposed to VPA. These results are consistent with those in vitro studies showing that, in cultured cells, VPA can inhibit the production of the infectious progeny of herpesviruses. This study also shows the efficient use of electronic healthcare records for clinical exploratory research studies.

Effectiveness and safety of long-term benzodiazepine use in anxiety disorders: a systematic review and meta-analysis

Long-term benzodiazepines (BZDs) use is not endorsed in the treatment guidelines for anxiety disorders, but is prevalent in the real-world clinical settings. A systematic literature review was performed by using PubMed (last search: May 2019) to identify randomized controlled trials (RCTs) or maintenance studies following RCT that examined the effectiveness of BZDs in patients with anxiety disorders for a duration of 13 weeks or more. Meta-analyses were then conducted regarding changes in the Hamilton Anxiety Rating Scale (HAM-A) scores from baseline through endpoint, all-cause discontinuation, side effects, and the numbers of panic attacks at endpoint. Eight studies were identified (N = 1228). There were no significant differences in all outcomes between BZDs and antidepressants after the initial 8-week treatment. While no significant difference was noted in the HAM-A score changes between BZDs and placebo, BZDs resulted in a lower discontinuation rate and more frequent constipation and dry mouth than placebo. Our study indicates that for those who respond to an initial 8-week treatment, continuing BZDs is equivalent to antidepressants in efficacy and safety. However, the limited number of studies warranted further investigations of the long-term effectiveness and safety of BZDs.

Risk of myocardial infarction associated with non‐steroidal anti‐inflammatory drugs: Impact of additional confounding control for variables collected from self‐reported data

What is known and objective

Important risk factors and over‐the‐counter (OTC) dispensing of non‐steroidal anti‐inflammatory drugs (NSAIDs) are often not routinely recorded in electronic health records. This study aimed to assess the impact of patient's reports on these factors on the risk of acute myocardial infarction (AMI) for NSAID use.

Methods

A nested case‐control study was conducted among adults in the Utrecht Cardiovascular Pharmacogenetics study. Cases were patients with a first diagnosis of AMI as a hospital discharge diagnosis and controls were those without AMI. NSAID exposure was either current use of selective COX‐2 inhibitors or conventional NSAIDs. Information was collected from The Dutch PHARMO Database Network (pharmacy records of drug dispensing linked to hospitalization records) and the patient's questionnaire (lifestyle factors, body mass index and history of cardiovascular diseases). Unconditional logistic regression analysis was used to calculate odds ratios (ORs) and to control for confounding factors.

Results

We identified 970 AMI cases and 2974 controls. Among cases, 11 (1.1%) and 185 (19.1%) were exposed to selective COX‐2 inhibitors and conventional NSAIDs, respectively. Compared to non‐use, none of these drug classes were associated with an increased risk of AMI (adjusted OR 1.07, 95% CI: 0.52‐2.18 and 0.93, 95% CI: 0.77‐1.12, respectively). Additional adjustment for potential confounders from patient's reports did not change the risk estimates (adjusted OR 1.08, 95% CI: 0.53‐2.22 and 0.89, 95% CI: 0.73‐1.09, respectively).

What is new and conclusion

Additional confounding control for variables from self‐reported data or considering self‐reported OTC NSAID use did not change the risk estimates for the association between NSAIDs and AMI.

Acetylcholinesterase inhibitors and the risk of osteoporotic fractures: nested case-control study

The objective of this study was to analyze the effect of acetylcholinesterase inhibitors (AChEIs) on the risk of osteoporotic fractures in Alzheimer patients. A nested case-control study was conducted on 1190 cases and 4760 controls. The use of AChEIs was found to decrease the risk of osteoporotic fractures in these patients.

INTRODUCTION

The objective of this study is to estimate the extent to which the use of AChEIs is associated with a reduction in the risk of osteoporotic fractures.

METHODS

A nested case-control study was conducted using data from the UK Clinical Practice Research Datalink (CPRD) and Hospital Episode Statistics (HES) database (1998-2013). The study cohort consisted of Alzheimer's Disease (AD) patients aged ≥ 65 years with no previous history of osteoporotic fractures at cohort baseline. Cases were individuals who suffered an osteoporotic fracture during the study period, whereas controls were subject who did not experience any osteoporotic fractures during the same period. Controls were drawn from the population time at risk while being matched to the cases in respect to age, sex, up-to-standard follow-up in the CPRD, calendar time, and duration of AD (control-to-case ratio: 4-to-1). Information on the use of AChEIs and the relevant potential confounders was ascertained from the CPRD database for all the cases and controls.

RESULTS

We identified 1190 cases and 4760 controls. Compared to non-users, any use of AChEIs prior to the fracture was associated with a reduction in the fracture risk [adjusted odds ratio (OR) 0.80 (confidence interval (CI) 95%, 0.70-0.91)]. The use of AChEIs corresponding to a proportion of days covered of 0.8-1.0 was associated with a lower osteoporotic fracture risk compared to non-use [adjusted OR 0.76 (CI 95%, 0.66-0.87)].

CONCLUSIONS

In this study using large primary care databases, the use and treatment adherence to AChEIs were associated with a decreased risk of osteoporotic fractures in elderly AD patients.

Benzodiazepines and risk of all cause mortality in adults: cohort study

Objectives To evaluate the risk of all cause mortality associated with initiating compared with not initiating benzodiazepines in adults, and to address potential treatment barriers and confounding related to the use of a non-active comparator group.Design Retrospective cohort study.Setting Large de-identified US commercial healthcare database (Optum Clinformatics Datamart).Participants 1:1 high dimensional propensity score matched cohort of benzodiazepine initiators, and randomly selected benzodiazepine non-initiators with a medical visit within 14 days of the start of benzodiazepine treatment (n=1 252 988), between July 2004 and December 2013. To address treatment barriers and confounding, patients were required to have filled one or more prescriptions for any medication in the 90 days and 91-180 days before the index date (ie, the date of starting benzodiazepine treatment for initiators and the date of the selected medical visit for benzodiazepine non-initiators) and the high dimensional propensity score was estimated on the basis of more than 300 covariates.Main outcome measure All cause mortality, determined by linkage with the Social Security Administration Death Master File.Results Over a six month follow-up period, 5061 and 4691 deaths occurred among high dimensional propensity score matched benzodiazepine initiators versus non-initiators (9.3 v 9.4 events per 1000 person years; hazard ratio 1.00, 95% confidence interval 0.96 to 1.04). A 4% (95% confidence interval 1% to 8%) to 9% (2% to 7%) increase in mortality risk was observed associated with the start of benzodiazepine treatment for follow-ups of 12 and 48 months and in subgroups of younger patients and patients initiating short acting agents. In secondary analyses comparing 1:1 high dimensional propensity score matched patients initiating benzodiazepines with an active comparator, ie, patients starting treatment with selective serotonin reuptake inhibitor antidepressants, benzodiazepine use was associated with a 9% (95% confidence interval 3% to 16%) increased risk.Conclusions This large population based cohort study suggests either no increase or at most a minor increase in risk of all cause mortality associated with benzodiazepine initiation. If a detrimental effect exists, it is likely to be much smaller than previously stated and to have uncertain clinical relevance. Residual confounding likely explains at least part of the small increase in mortality risk observed in selected analyses.

Risk of Ischemic Stroke Associated With Calcium Supplements With or Without Vitamin D: A Nested Case-Control Study

BACKGROUND

There is controversy surrounding the risk of ischemic stroke associated with the use of calcium supplements either in monotherapy or in combination with vitamin D.

METHODS AND RESULTS

A nested case-control study was performed with patients aged 40 to 89 years old, among whom a total of 2690 patients had a first episode of nonfatal ischemic stroke and for which 19 538 controls were randomly selected from the source population and frequency-matched with cases for age, sex, and calendar year. Logistic regression provided the odds ratios while adjusting for confounding factors. A sensitivity analysis was performed by restricting to patients who were new users of calcium supplements as either monotherapy or with vitamin D. Calcium supplementation with vitamin D was not associated with an increased risk of ischemic stroke (odds ratio 0.85; 95% confidence interval, 0.67-1.08) in the population as a whole or under any of the conditions examined (dose, duration, background cardiovascular risk, sex, or age). Calcium supplement monotherapy was not associated with an increased risk in the population as a whole (odds ratio 1.18; 95% confidence interval, 0.86-1.61), although a significant increased risk at high doses (≥1000 mg/day: odds ratio 2.09; 95% confidence interval, 1.25-3.49; <1000 mg: odds ratio 0.76; 95% confidence interval, 0.45-1.26) compared with nonuse was observed. The sensitivity analysis did not affect the inferences, with similar results observed among new users as to the overall study population.

CONCLUSIONS

This study suggests that calcium supplements given as monotherapy at high doses may increase the risk of ischemic stroke, whereas their combination with vitamin D seems to offset this hazard.

Risk of Hip Fracture in Older People Using Selective Serotonin Reuptake Inhibitors and Other Psychoactive Medicines Concurrently: A Matched Case-Control Study in Australia

Background

Few studies have assessed the risk of hip fracture following concurrent use of psychoactive medicines, and none has investigated combinations with selective serotonin reuptake inhibitors.

Objectives

To assess the risk of hip fracture in older people as a result of concurrent use of selective serotonin reuptake inhibitors and other psychoactive medicines.

Methods

A matched case–control design was employed. Cases were Australian Government Department of Veterans’ Affairs beneficiaries aged over 65 years who experienced a hip fracture between 2009 and 2012. Each case was matched with up to four randomly selected controls of the same age (±2 years) and sex. Medicine-hip fracture associations were estimated via conditional logistic regression. The relative excess risk due to interaction (RERI) was calculated to determine whether combined effects differed from the sum of individual effects.

Results

There were 8828 cases and 35,310 controls. The median age of subjects was 88 years and 63% were women. The risk of hip fracture was elevated for all medicines assessed individually, most notably selective serotonin reuptake inhibitors (initiation: odds ratio [OR] = 2.7, 95% confidence interval [CI] 2.1, 3.6) and opioids (initiation: OR = 2.3, 95% CI 1.9, 2.9). Combinations associated with an increased odds of hip fracture included addition of benzodiazepines to selective serotonin reuptake inhibitor therapy (OR = 3.0, 95% CI 1.9, 4.8; RERI = 0.9, 95% CI −0.5, 2.3), concurrent use of both opioids and selective serotonin reuptake inhibitors (OR = 2.2, 95% CI 1.9, 2.6; RERI = 0.1, 95% CI −0.3, 0.5), addition of opioids to selective serotonin reuptake inhibitor therapy (OR = 3.2, 95% CI 1.8, 5.5; RERI = −0.1, 95% CI −2.0, 1.7), and initiation of both benzodiazepines and selective serotonin reuptake inhibitors (OR = 4.7, 95% CI 1.7, 13; RERI = 1.3, 95% CI −3.8, 6.3). The RERI results suggested that the effect of each of these medicine combinations equalled the sum of the effects of individual medicine use.

Conclusions

In older people, the concurrent use of selective serotonin reuptake inhibitors and other psychoactive medicines increased the risk of hip fracture as much as the sum of the risks owing to individual medicine use. Our results highlight the need for prescribers to consider the sedative burden of medicines in each older patient as well as the potential for an additive risk of hip fracture when initiating additional psychoactive therapy.

Multi-centre, multi-database studies with common protocols: lessons learnt from the IMI PROTECT project

PURPOSE

To assess the impact of a variety of methodological parameters on the association between six drug classes and five key adverse events in multiple databases.

METHODS

The selection of Drug-Adverse Event pairs was based on public health impact, regulatory relevance, and the possibility to study a broad range of methodological issues. Common protocols and data analytical specifications were jointly developed and independently and blindly executed in different databases in Europe with replications in the same and different databases.

RESULTS

The association between antibiotics and acute liver injury, benzodiazepines and hip fracture, antidepressants and hip fracture, inhaled long-acting beta2-agonists and acute myocardial infarction was consistent in direction across multiple designs, databases and methods to control for confounding. Some variation in magnitude of the associations was observed depending on design, exposure and outcome definitions, but none of the differences were statistically significant. The association between anti-epileptics and suicidality was inconsistent across the UK CPRD, Danish National registries and the French PGRx system. Calcium channel blockers were not associated with the risk of cancer in the UK CPRD, and this was consistent across different classes of calcium channel blockers, cumulative durations of use up to >10 years and different types of cancer.

CONCLUSIONS

A network for observational drug effect studies allowing the execution of common protocols in multiple databases was created. Increased consistency of findings across multiple designs and databases in different countries will increase confidence in findings from observational drug research and benefit/risk assessment of medicines.

Benzodiazepine Use During Hospitalization: Automated Identification of Potential Medication Errors and Systematic Assessment of Preventable Adverse Events

Objective

Benzodiazepines and “Z-drug” GABA-receptor modulators (BDZ) are among the most frequently used drugs in hospitals. Adverse drug events (ADE) associated with BDZ can be the result of preventable medication errors (ME) related to dosing, drug interactions and comorbidities. The present study evaluated inpatient use of BDZ and related ME and ADE.

Methods

We conducted an observational study within a pharmacoepidemiological database derived from the clinical information system of a tertiary care hospital. We developed algorithms that identified dosing errors and interacting comedication for all administered BDZ. Associated ADE and risk factors were validated in medical records.

Results

Among 53,081 patients contributing 495,813 patient-days BDZ were administered to 25,626 patients (48.3%) on 115,150 patient-days (23.2%). We identified 3,372 patient-days (2.9%) with comedication that inhibits BDZ metabolism, and 1,197 (1.0%) with lorazepam administration in severe renal impairment. After validation we classified 134, 56, 12, and 3 cases involving lorazepam, zolpidem, midazolam and triazolam, respectively, as clinically relevant ME. Among those there were 23 cases with associated adverse drug events, including severe CNS-depression, falls with subsequent injuries and severe dyspnea. Causality for BDZ was formally assessed as ‘possible’ or ‘probable’ in 20 of those cases. Four cases with ME and associated severe ADE required administration of the BDZ antagonist flumazenil.

Conclusions

BDZ use was remarkably high in the studied setting, frequently involved potential ME related to dosing, co-medication and comorbidities, and rarely cases with associated ADE. We propose the implementation of automated ME screening and validation for the prevention of BDZ-related ADE.

'Big data' in mental health research: current status and emerging possibilities

PURPOSE

'Big data' are accumulating in a multitude of domains and offer novel opportunities for research. The role of these resources in mental health investigations remains relatively unexplored, although a number of datasets are in use and supporting a range of projects. We sought to review big data resources and their use in mental health research to characterise applications to date and consider directions for innovation in future.

METHODS

A narrative review.

RESULTS

Clear disparities were evident in geographic regions covered and in the disorders and interventions receiving most attention.

DISCUSSION

We discuss the strengths and weaknesses of the use of different types of data and the challenges of big data in general. Current research output from big data is still predominantly determined by the information and resources available and there is a need to reverse the situation so that big data platforms are more driven by the needs of clinical services and service users.

Association between Exposure to Benzodiazepines and Related Drugs and Survivorship of Total Hip Replacement in Arthritis: A Population-Based Cohort Study of 246,940 Patients

Background

Total hip replacement (THR) is successful in treating hip arthritis. Prosthetic survivorship may depend on the medications taken by the patient; particularly, the role of benzodiazepines and related drugs (Z-drugs) with THR revision has been poorly investigated. Our objective was to compare THR short-term survivorship according to level of exposure to benzodiazepine and Z-drugs.

Design, Setting and Participants

All French patients aged 40 years or older, having undergone primary THR from January 1, 2009, through December 31, 2012, for arthritis according to French national health insurance databases were included in the cohort. Outcome of interest was THR revision, including any surgical procedure in which the implant or any component was changed or removed. Follow-up started the day the primary THR was performed. Observations were right-censored on December 31, 2014, if neither revision nor death had yet occurred. Exposure of interest was the cumulative defined daily doses per day (cDDD/day) of benzodiazepines and Z-drugs dispensed within 6 months before or after inclusion. We defined four exposure groups; cDDD/d = 0: unexposed; <0.08: low exposure;] 0.08–0.38]: medium exposure; >0.38: high exposure. THR survivorship was assessed according to level of exposure to benzodiazepines and Z-drugs in univariate and multivariate Cox models adjusted for patient, THR and implanting center characteristics.

Results

The study cohort comprised 246,940 individuals: mean age at baseline, 69.9 years; women, 57.9%; unexposed: 51.7%; low exposure: 16.7%; medium exposure: 15.9%; and high exposure: 15.7%. During the median 45-month follow-up, 9043 individuals underwent prosthetic revision. Adjusted hazard ratios in low, medium and high exposed groups were 1.18 (95%CI, 1.12–1.26; P<0.001), 1.32 (95%CI, 1.24–1.40; P<0.001) and 1.37 (95%CI, 1.29–1.45; P<0.001), respectively, compared to unexposed.

Conclusion and Relevance

Exposure to benzodiazepines and Z-drugs is associated with an increased risk of THR revision, with a dose-response relationship. Cautious prescribing might be needed as well as careful history examination and assessment of risk for patients with a hip prosthesis.

A methodological comparison of two European primary care databases and replication in a US claims database: inhaled long-acting beta-2-agonists and the risk of acute myocardial infarction

PURPOSE

Results from observational studies on inhaled long-acting beta-2-agonists (LABA) and acute myocardial infarction (AMI) risk are conflicting, presumably due to variation in methodology. We aimed to evaluate the impact of applying a common study protocol on consistency of results in three databases.

METHODS

In the primary analysis, we included patients from two GP databases (Dutch-Mondriaan, UK-CPRD GOLD) with a diagnosis of asthma and/or COPD and at least one inhaled LABA or a "non-LABA inhaled bronchodilator medication" (short-acting beta-2-agonist or short-/long-acting muscarinic antagonist) prescription between 2002 and 2009. A claims database (USA-Clinformatics) was used for replication. LABA use was divided into current, recent (first 91 days following the end of a treatment episode), and past use (after more than 91 days following the end of a treatment episode). Adjusted hazard ratios (AMI-aHR) and 95 % confidence intervals (95 % CI) were estimated using time-dependent multivariable Cox regression models stratified by recorded diagnoses (asthma, COPD, or both asthma and COPD).

RESULTS

For asthma or COPD patients, no statistically significant AMI-aHRs (age- and sex-adjusted) were found in the primary analysis. For patients with both diagnoses, a decreased AMI-aHR was found for current vs. recent LABA use in the CPRD GOLD (0.78; 95 % CI 0.68-0.90) and in Mondriaan (0.55; 95 % CI 0.28-1.08), too. The replication study yielded similar results. Adjusting for concomitant medication use and comorbidities, in addition to age and sex, had little impact on the results.

CONCLUSIONS

By using a common protocol, we observed similar results in the primary analysis performed in two GP databases and in the replication study in a claims database. Regarding differences between databases, a common protocol facilitates interpreting results due to minimized methodological variations. However, results of multinational comparative observational studies might be affected by bias not fully addressed by a common protocol.

Do case-only designs yield consistent results across design and different databases? A case study of hip fractures and benzodiazepines

Background

The case‐crossover (CXO) and self‐controlled case series (SCCS) designs are increasingly used in pharmacoepidemiology. In both, relative risk estimates are obtained within persons, implicitly controlling for time‐fixed confounding variables.

Objectives

To examine the consistency of relative risk estimates of hip/femur fractures (HFF) associated with the use of benzodiazepines (BZD) across case‐only designs in two databases (DBs), when a common protocol was applied.

Methods

CXO and SCCS studies were conducted in BIFAP (Spain) and CPRD (UK). Exposure to BZD was divided into non‐use, current, recent and past use. For CXO, odds ratios (OR; 95%CI) of current use versus non‐use/past were estimated using conditional logistic regression adjusted for co‐medications (AOR). For the SCCS, conditional Poisson regression was used to estimate incidence rate ratios (IRR; 95%CI) of current use versus non/past‐use, adjusted for age. To investigate possible event‐exposure dependence the relative risk in the 30 days prior to first BZD exposure was also evaluated.

Results

In the CXO current use of BZD was associated with an increased risk of HFF in both DBs, AOR_BIFAP = 1.47 (1.29–1.67) and AOR_CPRD = 1.55 (1.41–1.70). In the SCCS, IRRs for current exposure was 0.79 (0.72–0.86) in BIFAP and 1.21 (1.13–1.30) in CPRD. However, when we considered separately the 30‐day pre‐exposure period, the IRR for current period was 1.43 (1.31–1.57) in BIFAP and 1.37 (1.27–1.47) in CPRD.

Conclusions

CXO designs yielded consistent results across DBs, while initial SCCS analyses did not. Accounting for event‐exposure dependence, estimates derived from SCCS were more consistent across DBs and designs. © 2015 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd.