The reporting of studies conducted using observational routinely collected health data statement for pharmacoepidemiology (RECORD-PE)

Sex disparities in the effect of statins on lipid parameters: The PharmLines Initiative

Real-world evidence on a potential statin effect modification by sex is inconclusive, especially for the primary prevention of cardiovascular disease (CVD). We aimed to quantify the differences in the effect of statins on lipid parameters between men and women.The PharmLines Initiative linked the Lifelines Cohort Study and the IADB.nl prescription database. This database covers a representative population from the Netherlands. We selected participants aged ≥40 years at the index date: the date of the first prescription of any statin monotherapy in the study period 2006 to 2017. Multivariate regression modeling was used to compare the difference of the mean percentage change of lipid parameters (% mean difference [MD]) from baseline to follow-up measurement between the sexes.Out of 5366 statin users from approximately 50,000 participants available in the final linked database, 685 were statin initiators. At baseline, women had significantly higher levels of mean total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) than men (all P values <.01). At follow-up, women had a significantly higher mean percentage change of HDL-C compared to men (adjusted % MD 5.59, 95% confidence interval [CI] 2.42-8.75, P < .01). There was no significant sex difference in other parameters, nor in the proportion of men and women who achieved LDL-C ≤2.5 mmol/L.Statins appear to have a greater effect on increasing HDL-C levels in women than men while showing similar effect on other lipid parameters in both sexes. Men should not be treated differently than women.

Stopping Versus Continuing Renin-Angiotensin System Inhibitors After Acute Kidney Injury and Adverse Clinical Outcomes; An Observational Study From Routine Care Data

Background

The risk–benefit ratio of continuing with renin–angiotensin system inhibitors (RASi) after an episode of acute kidney injury (AKI) is unclear. While stopping RASi may prevent recurrent AKI or hyperkalaemia, it may deprive patients of the cardiovascular benefits of using RASi.

Methods

We analysed outcomes of long-term RASi users experiencing AKI (stage 2 or 3, or clinically coded) during hospitalization in Stockholm and Sweden during 2007–18. We compared stopping RASi within 3 months after discharge with continuing RASi. The primary study outcome was the composite of all-cause mortality, myocardial infarction (MI) and stroke. Recurrent AKI was our secondary outcome and we considered hyperkalaemia as a positive control outcome. Propensity score overlap weighted Cox models were used to estimate hazard ratios (HRs), balancing 75 confounders. Weighted absolute risk differences (ARDs) were also determined.

Results

We included 10 165 individuals, of whom 4429 stopped and 5736 continued RASi, with a median follow-up of 2.3 years. The median age was 78 years; 45% were women and median kidney function before the index episode of AKI was 55 mL/min/1.73 m². After weighting, those who stopped had an increased risk [HR, 95% confidence interval (CI)] of the composite of death, MI and stroke [1.13, 1.07–1.19; ARD 3.7, 95% CI 2.6–4.8] compared with those who continued, a similar risk of recurrent AKI (0.94, 0.84–1.05) and a decreased risk of hyperkalaemia (0.79, 0.71–0.88).

Discussion

Stopping RASi use among survivors of moderate-to-severe AKI was associated with a similar risk of recurrent AKI, but higher risk of the composite of death, MI and stroke.

Determinants of long-term opioid prescribing in an urban population- a cross sectional study

BACKGROUND

Opioid prescribing has more than doubled in the UK between 1998 and 2016. Potential adverse health implications include dependency, falls and increased health expenditure.

AIM

To describe the predictors of long-term opioid prescribing (LTOP), (≥3 opioid prescriptions in a 90-day period).

DESIGN AND SETTING

A retrospective cross-sectional study in 41 General Practices in South London.

METHOD

Multi-level multivariable logistic regression to investigate the determinants of LTOP.

RESULTS

2,679 (0.8%) out of 320,639 registered patients ≥18 years were identified as having LTOP. Patients Were most likely to have LTOP, if: they had ≥5 long term conditions (LTCs) (adjusted odds ratio [AOR] 36.5, 95% confidence interval [CI] 30.4-43.8) or 2-4 LTCs (AOR 13.8, CI 11.9-16.1), in comparison to no LTCs, ≥75 years compared to 18-24 years (AOR 12.31, CI 7.1-21.5), smokers compared to non-smokers (AOR 2.2, CI 2.0-2.5), females compared to males (AOR 1.9, CI 1.7-2.0) and in the most deprived deprivation quintile (AOR 1.6, CI 1.4-1.8) compared to the least deprived. In a separate model examining individual long-term conditions (LTCs), the strongest associations for LTOP were noted for sickle cell disease (SCD) (AOR 18.4, CI 12.8-26.4), osteoarthritis (AOR 3.0, CI 2.8-3.3), rheumatoid arthritis (AOR 2.8, CI 2.2-3.4), depression (AOR 2.6, CI 2.3-2.8) and multiple sclerosis (OR 2.5, CI 1.4-4.4).

CONCLUSION

LTOP was significantly higher in those aged ≥75 years, with multi-morbidity or specific LTCs: sickle cell disease, osteoarthritis, rheumatoid arthritis, depression, and multiple sclerosis. These characteristics may enable the design of targeted interventions to reduce LTOP.

Reporting of abstracts in studies that used routinely collected data for exploring drug treatment effects: a cross-sectional survey

Background

In recent years, studies that used routinely collected data (RCD), such as electronic medical records and administrative claims, for exploring drug treatment effects, including effectiveness and safety, have been increasingly published. Abstracts of such studies represent a highly attended source for busy clinicians or policy-makers, and are important for indexing by literature database. If less clearly presented, they may mislead decisions or indexing. We thus conducted a cross-sectional survey to systematically examine how the abstracts of such studies were reported.

Methods

We searched PubMed to identify all observational studies published in 2018 that used RCD for assessing drug treatment effects. Teams of methods-trained collected data from eligible studies using pilot-tested, standardized forms that were developed and expanded from “The reporting of studies conducted using observational routinely collected health data statement for pharmacoepidemiology” (RECORD-PE) statement. We used descriptive analyses to examine how authors reported data source, study design, data analysis, and interpretation of findings.

Results

A total of 222 studies were included, of which 118 (53.2%) reported type of database used, 17 (7.7%) clearly reported database linkage, and 140 (63.1%) reported coverage of data source. Only 44 (19.8%) studies stated a predefined hypothesis, 127 (57.2%) reported study design, 140 (63.1%) reported statistical models used, 142 (77.6%) reported adjusted estimates, 33 (14.9%) mentioned sensitivity analyses, and 39 (17.6%) made a strong claim about treatment effect. Studies published in top 5 general medicine journals were more likely to report the name of data source (94.7% vs. 67.0%) and study design (100% vs. 53.2%) than those in other journals.

Conclusions

The under-reporting of key methodological features in abstracts of RCD studies was common, which would substantially compromise the indexing of this type of literature and prevent the effective use of study findings. Substantial efforts to improve the reporting of abstracts in these studies are highly warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12874-021-01482-9.

Trends in Prescriptions for Insomnia in a Province in China Between 2015 and 2019

BACKGROUND

The inappropriate use of pharmacological treatments for insomnia may increase patients' risk of serious adverse events. However, few epidemiological studies on the use of medications for insomnia in China have been conducted to date.

OBJECTIVE

We aimed to investigate the current pharmacological treatments for insomnia and guide the rational use of drugs.

METHODS

The prescription data of outpatients with insomnia between 2015 and 2019 in Zhejiang province were extracted from the Hospital Prescription Analysis Cooperative Project of China and evaluated. The demographic characteristics of insomnia and the proportion and prescription trends of different drugs were analyzed along with multidrug combinations for insomnia.

RESULTS

The number of patients with insomnia who were prescribed medications for insomnia increased from 2,385 in 2015 to 3,919 in 2019, with an increase of 64.32%, whereas the mean age of these patients decreased from 64.07 years to 60.94 years. There were nearly 1.42 times as many female patients prescribed medications for insomnia as male patients, and female patients tended to be younger than male patients. Benzodiazepines (53.99%) were the most common type of medicine for insomnia. The incidence of benzodiazepine usage decreased significantly yearly (P < 0.01), whereas the incidences of non-benzodiazepine receptor agonist (nBZRA) and antidepressant usage increased (P < 0.05). The most common benzodiazepine, nBZRA, antidepressant, and antipsychotic were estazolam, zolpidem, trazodone, and olanzapine, respectively. A total of 13.97% of outpatients with insomnia were prescribed multiple drugs for insomnia, even though nearly half of the drug combinations had similar pharmacological mechanisms.

CONCLUSIONS

Benzodiazepines remained the most common medication for insomnia, but the prescription rates of nBZRAs and antidepressants increased. Attention should be paid to multidrug combinations for insomnia, which may lead to an increased risk of serious adverse effects.

Adherence and persistence to rivaroxaban in non-valvular atrial fibrillation patients receiving 30- or 90-day supply prescription fills

BACKGROUND

It is unclear whether 90-day supply fills with rivaroxaban result in better adherence and persistence compared to 30-day supply fills. We assessed patients' adherence and persistence to rivaroxaban at 12- and 24-months in nonvalvular atrial fibrillation (NVAF) patients whose rivaroxaban prescriptions were filled every 30- vs. 90-days.

METHODS

Using the IBM MarketScan Commercial and Medicare Supplemental data sets, we identified adult NVAF patients with ≥12-months of continuous insurance coverage who filled a prescription in May 2018 and their immediate subsequent prescription for rivaroxaban for the same days' supply. We propensity score-matched 30- and 90-day rivaroxaban interval fill patients and compared the percentage with a proportion of days covered (PDC) ≥80%, mean PDC, and percentage persistent to rivaroxaban therapy over 12- and 24-months of follow-up.

RESULTS

Following propensity score matching, 2237 patients were included in the rivaroxaban 30- and 90-day supply fill cohorts. The proportion of patients with a PDC ≥80% was greater in the 90-day vs. 30-day cohort at both 12-months (odds ratio [OR] = 1.75, 95% confidence interval [CI] = 1.54-1.97) and 24-months (OR = 1.78, 95%CI = 1.58-2.00), as were mean PDC values (absolute difference in mean PDC = 9.4%, 95%CI = 8.2-10.7% at 12-months and 11.2%, 95%CI = 9.5-12.9% higher at 24-months, respectively). Persistence to rivaroxaban was not found to significantly differ between the 30- and 90-day supply cohorts at 12- or 24-months (assuming a 30-day permissible gap); however, greater persistence was observed with 90-day fills at both time points when a 14-day gap was utilized (HR = 1.22, 95%CI = 1.10-1.36 at 12-months and HR = 1.12, 95%CI = 1.02-1.22 at 24-months).

CONCLUSIONS

Dispensing 90-day supply fills with rivaroxaban appears to increase the proportion of patients achieving acceptable (PDC ≥80%) adherence as well as mean adherence compared to 30-day supply fills. Ninety-day rivaroxaban fills may also result in improved persistence vs. 30-day fills.

Low-dose aspirin and incidence of lung carcinoma in patients with chronic obstructive pulmonary disease in Hong Kong: A cohort study

BACKGROUND

Evidence suggests that chronic obstructive pulmonary disease (COPD) is associated with a higher risk of lung carcinoma. Using a territory-wide clinical electronic medical records system, we investigated the association between low-dose aspirin use (≤160 mg) among patients with COPD and incidence of lung carcinoma and the corresponding risk of bleeding.

METHODS AND FINDINGS

This is a retrospective cohort study conducted utilizing Clinical Data Analysis Reporting System (CDARS), a territory-wide database developed by the Hong Kong Hospital Authority. Inverse probability of treatment weighting (IPTW) was used to balance baseline covariates between aspirin nonusers (35,049 patients) with new aspirin users (7,679 patients) among all eligible COPD patients from 2005 to 2018 attending any public hospitals. The median age of the cohort was 75.7 years (SD = 11.5), and 80.3% were male. Competing risk regression with Cox proportional hazards model were performed to estimate the subdistribution hazard ratio (SHR) of lung carcinoma with low-dose aspirin and the associated bleeding events. Of all eligible patients, 1,779 (4.2%, 1,526 and 253 among nonusers and users) were diagnosed with lung carcinoma over a median follow-up period of 2.6 years (interquartile range [IQR]: 1.4 to 4.8). Aspirin use was associated with a 25% lower risk of lung carcinoma (SHR = 0.75, 95% confidence interval [CI] 0.65 to 0.87, p = <0.001) and 26% decrease in lung carcinoma-related mortality (SHR = 0.74, 95% CI 0.64 to 0.86, p = <0.001). Subgroup analysis revealed that aspirin was beneficial for patients aged above or below 75 years, but was also beneficial among populations who were male, nondiabetic, and nonhypertensive. Aspirin use was not associated with an increased risk of upper gastrointestinal bleeding (UGIB) (SHR = 1.19, 95% CI 0.94 to 1.53, p = 0.16), but was associated with an increased risk of hemoptysis (SHR = 1.96, 95% CI 1.73 to 2.23, p < 0.001). The main limitations of the study were (i) that one group of patients may be more likely to seek additional medical attention, although this was partially mitigated by the use of propensity score analysis; and (ii) the observational nature of the study renders it unable to establish causality between aspirin use and lung carcinoma incidence.

CONCLUSIONS

In this study, we observed that low-dose aspirin use was associated with a lower risk of lung carcinoma and lung carcinoma-related mortality among COPD patients. While aspirin was not associated with an increased risk of UGIB, the risk of hemoptysis was elevated.

Toward a better understanding about real-world evidence

BACKGROUND

There has been an interest in real-world evidence (RWE) in recent years. RWE is usually generated from data derived from routine healthcare, such as electronic healthcare records and disease registries. While RWE has many advantages, it is often open to various biases, which may distort results. Appropriate understanding and interpretation are critical to the best use of RWE in healthcare decisions.

METHODS

On the basis of a literature review and empirical research experience, we summarised the concept and methodological framework of RWE, and discussed in detail methodological issues specific to routinely collected healthcare data and observational studies using such data.

RESULTS

RWE is derived from a spectrum of data generated from the real-world setting, using two broad study designs including observational studies and pragmatic clinical trials. Real-world data may usually be collected through routine practice or sometimes actively collected with a research purpose. Observational studies using routinely collected data (RCD) are the most common type of RWE, although they are prone to biases. When planning and implementing RWE studies, coherent working steps are warranted, including definition of a clear and answerable research question, development of a research team, selection of a fit-for-purpose data source, choice of state-of-the-art study design, establishing a database with transparent data processing, performing multiple statistical analysis to control bias, and reporting results in accordance with established guidelines.

CONCLUSIONS

RWE has been mounting over the years. The appropriate interpretation and use of such evidence often warrant adequate understanding about methodology. Researchers and policymakers should be aware of the methodological pitfalls when generating and interpreting RWE.

Assessing and Interpreting Real-World Evidence Studies: Introductory Points for New Reviewers

Nonrandomized real-world evidence (RWE) studies are conducted using healthcare data collected as part of clinical practice. As RWE studies are increasingly considered for regulatory, coverage, and other clinical decision making, nonspecialists will find themselves in the position of assessing the validity of RWE studies, a field that may be less familiar to them. This introductory guide provides conceptual guidance for reviewing RWE studies and is particularly directed at professionals for whom this is new or whose prior experience has primarily been in reviewing randomized controlled trial evidence. We focus on RWE studies that make causal inference, evaluating whether one treatment option is better, worse, or neutral compared to another. Although we provide citations to direct the reader to resources with more details on complex issues, this guide cannot substitute for years of training and expertise in the field.

Higher-Dose Gabapentinoids and the Risk of Adverse Events in Older Adults With CKD: A Population-Based Cohort Study

RATIONALE & OBJECTIVE

Gabapentinoids are an opioid substitute whose elimination by the kidneys is reduced as kidney function declines. To inform their safe prescribing in older adults with chronic kidney disease (CKD), we examined the 30-day risk of serious adverse events according to the prescribed starting dose.

STUDY DESIGN

Population-based cohort study.

SETTING & PARTICIPANTS

74,084 older adults (64% women; median age 79 [interquartile range 73-85]) with CKD (defined as an estimated glomerular filtration rate [eGFR] <60 mL/min/1.73m2 while not receiving dialysis) and a newly prescribed a gabapentinoid between 2008-2020 in Ontario, Canada.

EXPOSURE

Higher-dose gabapentinoids (gabapentin >300 mg/day or pregabalin >75 mg/day) vs lower-dose gabapentinoids (gabapentin ≤300 mg/day or pregabalin ≤75 mg/day).

OUTCOMES

The primary composite outcome was the 30-day risk of a hospital visit with encephalopathy, a fall, a fracture, or a hospitalization with respiratory depression.

ANALYTICAL APPROACH

Comparison groups were balanced on indicators of baseline health using inverse probability of treatment weighting using propensity score analysis that generated a pseudo-sample for the reference group with a distribution of measured covariates similar to the exposed group. Weighted risk ratios (RR) were estimated using modified Poisson regression, and weighted risk differences (RD) estimated using binomial regression. Pre-specified subgroup analyses were conducted by eGFR category and type of gabapentinoid.

RESULTS

Among 74,084 patients were identified with CKD and a new prescription for gabapentin or pregabalin 41% started at >300 mg/day and >75 mg/day, respectively. From this set of patients a weighted study population with a size of 61,367 was generated. Patients who started at a higher dose had a 30-day risk of the primary outcome higher than the risk among with patients who started at lower dose. Within the weighted population, the numbers of events for higher vs. lower dose were 585/30,660 [1.9%] vs 462/30,707 [1.5%], respectively. The weighted RR was 1.27 [95% CI, 1.13 to 1.42] and the weighted RD was 0.40% [95% CI, 0.21% to 0.60%]). In subgroup analyses, neither multiplicative nor additive interactions were statistically significant.

LIMITATIONS

Residual confounding.

CONCLUSIONS

In this population-based study, starting a gabapentinoid at a higher vs lower dose was associated with a slightly higher risk of a hospital stay with encephalopathy, a fall, or a fracture, or hospitalization with respiratory depression. If verified, these risks should be balanced against the benefits of using a higher-dose gabapentinoid.

Heterogeneity in the identification of potential drug-drug interactions in the intensive care unit: A systematic review, critical appraisal, and reporting recommendations

Patients admitted to the intensive care unit (ICU) are frequently exposed to potential drug‐drug interactions (pDDIs). However, reported frequencies of pDDIs in the ICU vary widely between studies. This can be partly explained by significant variation in their methodological approach. Insight into methodological choices affecting pDDI frequency would allow for improved comparison and synthesis of reported pDDI frequencies. This study aimed to evaluate the association between methodological choices and pDDI frequency and formulate reporting recommendations for pDDI frequency studies in the ICU. The MEDLINE database was searched to identify papers reporting pDDI frequency in ICU patients. For each paper, the pDDI frequency and methodological choices such as pDDI definition and pDDI knowledge base were extracted, and the risk of bias was assessed. Each paper was categorized as reporting a low, medium, or high pDDI frequency. We sought associations between methodological choices and pDDI frequency group. Based on this comparison, reporting recommendations were formulated. Analysis of methodological choices showed significant heterogeneity between studies, and 65% of the studies had a medium to high risk of bias. High risk of bias, small sample size, and use of drug prescriptions instead of administrations were related to a higher pDDI frequency. The findings of this review may support researchers in designing a reliable methodology assessing pDDI frequency in ICU patients. The reporting recommendations may contribute to standardization, comparison, and synthesis of pDDI frequency studies, ultimately improving knowledge about pDDIs in and outside the ICU setting.

Self-controlled case series design in vaccine safety: a systematic review

BACKGROUND

: An increasing number of vaccine safety studies using the self-controlled case-series (SCCS) design have been conducted in the last decade. However, there has been no comprehensive evaluation of the methodology and reporting quality of these observational studies. The purpose of this paper is to document the methodological features of studies that focused on vaccine safety using the SCCS design, and to evaluate the reporting quality of these studies to suggest future improvements on appropriate design and transparent reporting.

METHODS

: Databases including Medline, Embase, Web of Science, Scopus and Chinese databases were searched from inception to May 31, 2021. All observational studies regarding vaccine safety using a SCCS design were selected. Information regarding methodological elements were extracted. In addition, reporting quality was assessed using the REporting of studies Conducted using Observational Routinely collected health Data statement for PharmacoEpidemiology (RECORD-PE).

RESULTS

: Of the 105 studies identified, administrative databases were the main data source for vaccination records and adverse events following immunization (AEFI). 28 articles (27%) used multiple designs to verify the association, and the results obtained with the SCCS design were robust. The top three AEFI studied were intussusception, Guillain-Barré syndrome, and convulsions. Only 21 studies (20%) reported the approach for case validation by chart review. The healthy vaccinee effect was considered by 51studies (49%), with 16 of them (31%) using extended SCCS models to alleviate this effect. Overall, the reporting quality of included studies could be improved.

CONCLUSIONS

: This study systematically reviewed the methodology of studies regarding vaccine safety using a SCCS design and critically assessed their respective reporting quality. Case validation, the validity of assumptions for standard SCCS, and quality of reporting should be given more importance in future research projects.

Broadening the reach of the FDA Sentinel system: A roadmap for integrating electronic health record data in a causal analysis framework

The Sentinel System is a major component of the United States Food and Drug Administration's (FDA) approach to active medical product safety surveillance. While Sentinel has historically relied on large quantities of health insurance claims data, leveraging longitudinal electronic health records (EHRs) that contain more detailed clinical information, as structured and unstructured features, may address some of the current gaps in capabilities. We identify key challenges when using EHR data to investigate medical product safety in a scalable and accelerated way, outline potential solutions, and describe the Sentinel Innovation Center's initiatives to put solutions into practice by expanding and strengthening the existing system with a query-ready, large-scale data infrastructure of linked EHR and claims data. We describe our initiatives in four strategic priority areas: (1) data infrastructure, (2) feature engineering, (3) causal inference, and (4) detection analytics, with the goal of incorporating emerging data science innovations to maximize the utility of EHR data for medical product safety surveillance.

Use of antipsychotic and sedative medications in older patients in the emergency department

BACKGROUND

Antipsychotics and sedatives are used to treat agitation in the emergency department (ED) but carry significant risk in older adults. Our objective was to determine factors associated with their administration to older ED patients.

METHODS

This was an observational study using data from the 2014-2017 National Hospital Ambulatory Medical Care Survey. We identified ED visits for patients aged ≥65 years and determined whether an antipsychotic or sedative was administered. Visits related to substance use/withdrawal, other psychiatric complaints, and intubation were excluded. We performed multivariable logistic regression to identify risk factors for antipsychotic or sedative administration.

RESULTS

Of the 78.7 million ED visits that met inclusion criteria, 3.5% involved at least one dose of antipsychotic or sedative medication; 13% involved an antipsychotic and 92% a sedative. Factors associated with antipsychotic administration included nursing home residence (adjusted odds ratio [aOR]: 2.67; 95% CI: 1.05-6.80), dementia (aOR: 5.62; 95% CI: 2.44-12.94), and delirium (aOR: 7.33; 95% CI: 2.21-24.32). Sedative administration was positively associated with CT or MR imaging (aOR: 1.86; 95% CI: 1.42-2.43), urbanicity of ED (aOR: 1.46; 95% CI: 1.02-2.08), and female gender (aOR: 1.47; 95% CI: 1.08-1.99) and negatively associated with older age (age: 75-84; aOR: 0.67; 95% CI: 0.49-0.91; age: 85+; aOR: 0.63; 95% CI: 0.45-0.88; reference age: 65-74 years). Antipsychotic and sedative administration were associated with prolonged ED lengths of stay and hospital admission.

CONCLUSION

We identified patient- and facility-level factors associated with sedative and antipsychotic administration in older ED patients. Antipsychotic and sedative administration were associated with prolonged ED lengths of stay and hospital admission.

Crosstalk between Statins and Cancer Prevention and Therapy: An Update

The importance of statins in cancer has been discussed in many studies. They are known for their anticancer properties against solid tumors of the liver or lung, as well as diffuse cancers, such as multiple myeloma or leukemia. Currently, the most commonly used statins are simvastatin, rosuvastatin and atorvastatin. The anti-tumor activity of statins is largely related to their ability to induce apoptosis by targeting cancer cells with high selectivity. Statins are also involved in the regulation of the histone acetylation level, the disturbance of which can lead to abnormal activity of genes involved in the regulation of proliferation, differentiation and apoptosis. As a result, tumor growth and its invasion may be promoted, which is associated with a poor prognosis. High levels of histone deacetylases are observed in many cancers; therefore, one of the therapeutic strategies is to use their inhibitors. Combining statins with histone deacetylase inhibitors can induce a synergistic anticancer effect.

Risk of bias in observational studies using routinely collected data of comparative effectiveness research: a meta-research study

BACKGROUND

To assess the completeness of reporting, research transparency practices, and risk of selection and immortal bias in observational studies using routinely collected data for comparative effectiveness research.

METHOD

We performed a meta-research study by searching PubMed for comparative effectiveness observational studies evaluating therapeutic interventions using routinely collected data published in high impact factor journals from 01/06/2018 to 30/06/2020. We assessed the reporting of the study design (i.e., eligibility, treatment assignment, and the start of follow-up). The risk of selection bias and immortal time bias was determined by assessing if the time of eligibility, the treatment assignment, and the start of follow-up were synchronized to mimic the randomization following the target trial emulation framework.

RESULT

Seventy-seven articles were identified. Most studies evaluated pharmacological treatments (69%) with a median sample size of 24,000 individuals. In total, 20% of articles inadequately reported essential information of the study design. One-third of the articles (n = 25, 33%) raised some concerns because of unclear reporting (n = 6, 8%) or were at high risk of selection bias and/or immortal time bias (n = 19, 25%). Only five articles (25%) described a solution to mitigate these biases. Six articles (31%) discussed these biases in the limitations section.

CONCLUSION

Reporting of essential information of study design in observational studies remained suboptimal. Selection bias and immortal time bias were common methodological issues that researchers and physicians should be aware of when interpreting the results of observational studies using routinely collected data.

The Challenge of Assessing Treatment Effectiveness in a Real-World Setting

Real-world data derived from observational studies, particularly from administrative health care and insurance claims databases, are increasingly being used to evaluate treatment effectiveness. To control for potential biases, a number of analytical techniques have been developed. However, the procedures used can be far from intuitive, and this along with other methodological issues can make it challenging to assess whether reported results are real or artefactual. This commentary summarizes some of the issues associated with evaluating treatment effectiveness in the real-world setting, at the same time highlighting the important role observational studies can play.

Hospitalizations and deaths related to adverse drug events worldwide: Systematic review of studies with national coverage

PURPOSE

Adverse drug events are related to negative outcomes in healthcare, including hospitalization, increased duration of hospital stay and death. The aim of this study was to conduct a systematic review to evaluate hospitalizations and deaths related to adverse drug events worldwide, reported in studies with national coverage.

METHODS

The protocol was registered in PROSPERO (CRD42020157008). We performed a systematic search on Medline, Embase, CINAHL, LILACS, and the Cochrane Library (until March 2020) using pre-specified terms. We included published studies that reported data on hospitalizations and/or deaths related to adverse drug events from a national perspective and the use of secondary data as a source of information. Two reviewers independently extracted and synthesized data. The quality of the studies was assessed using an adapted version of the Joanna Briggs Institute critical appraisal checklist for prevalence studies. Narrative summaries of findings were undertaken.

RESULTS

Among 59,336 citations, 62 studies were included for data extraction and synthesis. Among these studies, 41 studies included the outcome of hospitalization, 16 included the death outcome, and five included both outcomes. Administrative databases regarding discharges and registries of vital statistics were the most common sources of information. The relative frequency of hospitalizations ranged from 0.03% to 7.3%, and from 9.7 to 383.0/100,000 population, whereas mortality rate ranged from 0.1 to 7.88/100,000 population.

CONCLUSION

Our study highlights information about adverse drug events using large administrative databases in a national scenario and provides an overview of databases and methods implemented to detect adverse drug events.

A systematic, concept-based method of developing the exposure measure for drug safety and effectiveness studies

PURPOSE

In drug safety and effectiveness studies based on secondary data, the choice of an appropriate exposure measure for a given outcome can be challenging. Different measures of exposure can yield different estimates of treatment effect and safety. There is a knowledge gap with respect to developing and refining measures of drug exposure, to ensure that the exposure measure addresses the study question and is suitable for statistical analysis.

METHODS

We present a transparent, step-by-step approach to the development of drug exposure measures involving secondary data. This approach would be of interest to students and investigators with initial training in pharmacoepidemiology. We illustrate the approach using a study about Parkinson's disease.

RESULTS

We described the exposure specifications according to the study question. Next, we refined the exposure measure by linking it to knowledge about four major concepts in drug safety and effectiveness studies: drug use patterns, duration, timing, and dose. We then used this knowledge to guide the ultimate choice of exposure measure: time-varying, cumulative 6-month exposure to tamsulosin (a drug used to treat prostate hyperplasia).

CONCLUSIONS

The proposed approach links exposure specifications to four major concepts in drug safety and effectiveness studies. Formulating subject-matter knowledge about these major concepts provides an avenue to develop the rationale and specifications for the exposure measure.

COVID-19 versus influenza A/B supeRInfectionS in the IntenSive care unit (CRISIS): Protocol for a Danish nationwide cohort study

BACKGROUND

Superinfection following viral infection is a known complication, which may lead to longer hospitalisation and worse outcome. Empirical antibiotic therapy may prevent bacterial superinfections, but may also lead to overuse, adverse effects and development of resistant pathogens. Knowledge about the incidence of superinfections in intensive care unit (ICU) patients with severe Coronavirus Disease 2019 (COVID-19) is limited.

METHODS

We will conduct a nationwide cohort study comparing the incidence of superinfections in patients with severe COVID-19 admitted to the ICU compared with ICU patients with influenza A/B in Denmark. We will include approximately 1000 patients in each group from the time period of 1 October 2014 to 30 April 2019 and from 10 March 2020 to 1 March 2021 for patients with influenza and COVID-19, respectively. The primary outcome is any superinfection within 90 days of admission to the ICU. We will use logistic regression analysis comparing COVID-19 with influenza A/B after adjustment for relevant predefined confounders. Secondarily, we will use unadjusted and adjusted logistic regression analyses to assess six potential risk factors (sex, age, cancer [including haematological], immunosuppression and use of life support on day 1 in the ICU) for superinfections and compare outcomes in patients with COVID-19 with/without superinfections, and present descriptive data regarding the superinfections.

CONCLUSION

This study will provide important knowledge about superinfections in ICU patients with severe COVID-19.

Repurposing haloperidol for the treatment of rheumatoid arthritis: an integrative approach using data mining techniques

Introduction

Treatment of rheumatoid arthritis (RA) has advanced with the introduction of biological disease-modifying antirheumatic drugs. However, more than 20% of patients with RA still have moderate or severe disease activity. Hence, novel antirheumatic drugs are required. Recently, drug repurposing, a process of identifying new indications for existing drugs, has received great attention. Furthermore, a few reports have shown that antipsychotics are capable of affecting several cytokines that are also modulated by existing antirheumatic drugs. Therefore, we investigated the association between antipsychotics and RA by data mining using real-world data and bioinformatics databases.

Methods

Disproportionality and sequence symmetry analyses were employed to identify the associations between the investigational drugs and RA using the US Food and Drug Administration Adverse Event Reporting System (2004-2016) and JMDC administrative claims database (January 2005-April 2017; JMDC Inc., Tokyo, Japan), respectively. The reporting odds ratio (ROR) and information component (IC) were used in the disproportionality analysis to indicate a signal. The adjusted sequence ratio (SR) was used in the sequence symmetry analysis to indicate a signal. The bioinformatics analysis suite, BaseSpace Correlation Engine (Illumina, CA, USA) was employed to explore the molecular mechanisms associated with the potential candidates identified by the drug-repurposing approach.

Results

A potential inverse association between the antipsychotic haloperidol and RA, which exhibited significant inverse signals with ROR, IC, and adjusted SR, was found. Furthermore, the results suggested that haloperidol may exert antirheumatic effects by modulating various signaling pathways, including cytokine and chemokine signaling, major histocompatibility complex class-II antigen presentation, and Toll-like receptor cascade pathways.

Conclusion

Our drug-repurposing approach using data mining techniques identified haloperidol as a potential antirheumatic drug candidate.

Cardiovascular Safety of Metoclopramide Compared to Domperidone: A Population-Based Cohort Study

BACKGROUND

Metoclopramide and domperidone are common prokinetics used to alleviate gastrointestinal symptoms. However, both drugs may trigger ventricular arrhythmias.

AIM

We conducted this population-based study to compare the 30-day cardiovascular safety of metoclopramide versus domperidone in outpatient care.

METHODS

We used health care databases to identify a cohort of patients in Ontario, Canada newly dispensed metoclopramide or domperidone. Inverse probability of treatment weighting based on propensity scores was used to balance the baseline characteristics of the two groups. All outcomes were assessed in the 30 days following drug dispensing. The primary outcome was hospital encounter with ventricular arrhythmia. The secondary outcomes were hospital encounter with cardiac arrest, all-cause mortality and cardiovascular mortality.

RESULTS

We identified 196,544 patients, 19% of whom were prescribed metoclopramide. There was no difference in the risk of a hospital encounter with ventricular arrythmia (0.02% in both groups), or cardiac arrest (0.10% with metoclopramide and 0.08% with domperidone). However, 1.34% of patients died after starting metoclopramide compared to 0.52% of patients starting domperidone; weighted risk ratio 2.50 (95% confidence interval [CI] 2.13 to 3.03). Similarly, 0.42% of patients died of cardiovascular causes after starting metoclopramide compared to 0.19 % of patients starting domperidone; weighted risk ratio 2.00 (95% CI 1.44 to 2.77).

CONCLUSION

The 30-day risk for a hospital encounter with ventricular arrhythmia was low for both metoclopramide and domperidone, with no significant difference in the rate between the two drugs. The higher 30-day risk of death observed with metoclopramide compared with domperidone in this study has also been observed in other studies and warrants further investigation.

The Risk of Acute Kidney Injury with Oral Anticoagulants in Elderly Adults with Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Anticoagulation with either a vitamin K antagonist or a direct oral anticoagulant may be associated with AKI. Our objective was to assess the risk of AKI among elderly individuals with atrial fibrillation newly prescribed a direct oral anticoagulant (dabigatran, rivaroxaban, or apixaban) versus warfarin.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our population-based cohort study included 20,683 outpatients in Ontario, Canada, ≥66 years with atrial fibrillation who were prescribed warfarin, dabigatran, rivaroxaban, or apixaban between 2009 and 2017. Inverse probability of treatment weighting on the basis of derived propensity scores for the treatment with each direct oral anticoagulant was used to balance baseline characteristics among patients receiving each of the three direct oral anticoagulants compared with warfarin. Cox proportional hazards regression was performed in the weighted population to compare the association between the prescribed anticoagulant and the outcomes of interest. The exposure was an outpatient prescription of warfarin or one of the direct oral anticoagulants. The primary outcome was a hospital encounter with AKI, defined using Kidney Disease Improving Global Outcomes thresholds. Prespecified subgroup analyses were conducted by eGFR category and by the percentage of international normalized ratio measurements in range, a validated marker of anticoagulation control.

RESULTS

Each direct oral anticoagulant was associated with a significantly lower risk of AKI compared with warfarin (weighted hazard ratio, 0.65; 95% confidence interval, 0.53 to 0.80 for dabigatran; weighted hazard ratio, 0.85; 95% confidence interval, 0.73 to 0.98 for rivaroxaban; and weighted hazard ratio, 0.81; 95% confidence interval, 0.72 to 0.93 for apixaban). In the subgroup analysis, the lower risk of AKI associated with each direct oral anticoagulant was consistent across each eGFR strata. The risk of AKI was significantly lower among users of each of the direct oral anticoagulants compared with warfarin users who had a percentage of international normalized ratio measurements ≤56%.

CONCLUSIONS

Direct oral anticoagulants were associated with a lower risk of AKI compared with warfarin.

Conducting Real-world Evidence Studies on the Clinical Outcomes of Diabetes Treatments

Real-world evidence (RWE), the understanding of treatment effectiveness in clinical practice generated from longitudinal patient-level data from the routine operation of the healthcare system, is thought to complement evidence on the efficacy of medications from randomized controlled trials (RCTs). RWE studies follow a structured approach. (1) A design layer decides on the study design, which is driven by the study question and refined by a medically informed target population, patient-informed outcomes, and biologically informed effect windows. Imagining the randomized trial we would ideally perform before designing an RWE study in its likeness reduces bias; the new-user active comparator cohort design has proven useful in many RWE studies of diabetes treatments. (2) A measurement layer transforms the longitudinal patient-level data stream into variables that identify the study population, the pre-exposure patient characteristics, the treatment, and the treatment-emergent outcomes. Working with secondary data increases the measurement complexity compared to primary data collection that we find in most RCTs. (3) An analysis layer focuses on the causal treatment effect estimation. Propensity score analyses have gained in popularity to minimize confounding in healthcare database analyses. Well-understood investigator errors, like immortal time bias, adjustment for causal intermediates, or reverse causation, should be avoided. To increase reproducibility of RWE findings, studies require full implementation transparency. This article integrates state-of-the-art knowledge on how to conduct and review RWE studies on diabetes treatments to maximize study validity and ultimately increased confidence in RWE-based decision making.

Paediatric outpatient prescriptions in France between 2010 and 2019: A nationwide population-based study: Paediatric outpatient prescriptions in France, 2010 to 2019

Background

Paediatric outpatient prescription (POP) monitoring is pivotal to identify inadequate prescriptions and optimize drug use. We aimed at describing recent trends in POPs in France.

Methods

All reimbursed dispensations of outpatient prescribed drugs (excluding vaccines) were prospectively collected for the paediatric population (<18 years old) in the French national health database in 2010-2011 and 2018-2019 (mean 117,356,938/year). POP prevalence (proportion of children receiving ≥1 drug prescriptions/year) was calculated by age groups and compared by prevalence rate ratios (PRRs). Given the large sample size, 95% confidence intervals of POP prevalences and PRRs did not differ from estimates.

Findings

Among the 14,510,023 children resident in France in 2018-2019, mean POP prevalence was 857‰ children. Most prescribed therapeutic classes were analgesics (643‰), antibiotics (405‰), nasal corticosteroids (328‰), nonsteroidal anti-inflammatory drugs (NSAIDs) (244‰), antihistamines (246‰) and systemic corticosteroids (210‰). POPs decreased with age from 976‰ for infants to 782‰ for adolescents. Children <6 years old were notably more exposed to inhaled corticosteroids (PRR=3.06), non-penicillin beta-lactam antibacterial agents (PRR=3.05) and systemic corticosteroids (PRR=2.11) than older ones. The POP prevalence was slightly higher (PRR=1.04) during 2018-2019 than 2010-2011, with marked increases for anti-emetics (PRR=1.84), vitamin D (PRR=1.49), proton pump inhibitors (PRR=1.42), systemic contraceptives (PRR=1.24) and nasal corticosteroids (PRR=1.21) and decreases for propulsive/prokinetic agents (PRR=0.09), NSAIDs (PRR=0.73) and systemic antibiotics (PRR=0.88).

Interpretation

POP remained highly prevalent in France throughout the 2010s, especially for children <6 years old, with only a few improvements for selected therapeutic classes. These findings should prompt clinical guidance campaigns and/or regulatory policies.

Funding

Internal funding.

Retinoids are not linked to risk of multiple sclerosis: A Danish nationwide cohort study

BACKGROUND AND PURPOSE

Multiple sclerosis (MS) is a chronic immune-mediated disease of the central nervous system with an undetermined etiology. Retinoids may have immunomodulatory effects that favorably influence MS progression. We aimed to explore the yet unknown relationship between exposure to retinoids and the risk of acquiring MS.

METHODS

We performed a nationwide cohort study in the Danish population in the period 1998-2016, comparing MS incidence in three groups: users of systemic retinoids; users of topical retinoids (negative control group); and users of non-retinoid acne drugs (control group). We used data from the Danish Multiple Sclerosis Registry (DMSR), the Danish National Prescription Registry and the Danish National Patient Registry. Linkage was obtained through the personal identification number (CPR number). We addressed confounding by three-way propensity score (PS)-matching weights. Additionally, to evaluate a cumulative dose-response effect for systemic retinoids on MS incidence, we conducted a case-control study, nested within the cohort.

RESULTS

A total of 257,193 users of non-retinoid acne drugs, 130,560 users of topical retinoids, and 75,610 users of systemic retinoids were included. Systemic retinoid use was not associated with a reduced risk of MS compared to non-retinoid acne drug use in crude (hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.61 to 1.05]) and weighted analyses (HR 0.89, 95% CI 0.67 to 1.20). There was no evidence of a cumulative dose-response association between systemic retinoids and MS incidence.

CONCLUSIONS

Use of systemic retinoids was not associated with a reduced incidence of MS compared to use of non-retinoid acne drugs in this study.

Perinatal pharmacoepidemiology: How often are key methodological elements reported in publications?

PURPOSE

Publications provide important information for clinicians, researchers, and patients. Key methodological elements must be reported for maximum transparency. We identified key methodological elements necessary for fully understanding perinatal pharmacoepidemiology research and quantified the proportion of studies that reported these elements in a sample of publications.

METHODS

Key methodological elements were identified from guidelines from regulatory agencies, literature, and subject-matter knowledge: source of information to determine pregnancy start; mother- or father-infant linkages (process, success rate); unit of analysis; and whether non-live births and fetuses with various anomalies were included in the study population. We conducted a literature review for recent observational studies on medical product utilization or safety during pregnancy and estimated the prevalence of reporting these elements.

RESULTS

Data were extracted from a random sample of 100 publications; 8% were published in epidemiology/pharmacoepidemiology journals; 85% were medical product-safety studies. Of publications for which each element was applicable, 43% reported the source for determining pregnancy start; 57%, whether the study population included multifetal pregnancies; 39%, whether it included more than one pregnancy per woman; 27%, whether it included fetuses with chromosomal abnormalities; 60%, fetuses with major congenital malformations; and 93%, non-live births. Of the 20 studies with mother-infant linkage, 35% described the process; 21% reported the linkage success rate. Among studies with more than one pregnancy/offspring per woman, 22% reported methods addressing sibling correlation.

CONCLUSIONS

In this sample of pregnancy-related pharmacoepidemiology publications, completeness of reporting could have been improved. A pregnancy-specific checklist would increase transparency in the dissemination of study results.

COVID-19: protocol for observational studies utilizing near real-time electronic Australian general practice data to promote effective care and best-practice policy-a design thinking approach

BACKGROUND

Health systems around the world have been forced to make choices about how to prioritize care, manage infection control and maintain reserve capacity for future disease outbreaks. Primary healthcare has moved into the front line as COVID-19 testing transitions from hospitals to multiple providers, where tracking testing behaviours can be fragmented and delayed. Pooled general practice data are a valuable resource which can be used to inform population and individual care decision-making. This project aims to examine the feasibility of using near real-time electronic general practice data to promote effective care and best-practice policy.

METHODS

The project will utilize a design thinking approach involving all collaborators (primary health networks [PHNs], general practices, consumer groups, researchers, and digital health developers, pathology professionals) to enhance the development of meaningful and translational project outcomes. The project will be based on a series of observational studies utilizing near real-time electronic general practice data from a secure and comprehensive digital health platform [POpulation Level Analysis and Reporting (POLAR) general practice data warehouse]. The study will be carried out over 1.5 years (July 2020-December 2021) using data from over 450 general practices within three Victorian PHNs and Gippsland PHN, Eastern Melbourne PHN and South Eastern Melbourne PHN, supplemented by data from consenting general practices from two PHNs in New South Wales, Central and Eastern Sydney PHN and South Western Sydney PHN.

DISCUSSION

The project will be developed using a design thinking approach, leading to the building of a meaningful near real-time COVID-19 geospatial reporting framework and dashboard for decision-makers at community, state and nationwide levels, to identify and monitor emerging trends and the impact of interventions/policy decisions. This will integrate timely evidence about the impact of the COVID-19 pandemic related to its diagnosis and treatment, and its impact across clinical, population and general practice levels.

Approaches to Assessing the Quality of Observational Studies of Clinical Practice Based on the Big Data Analysis

The article is devoted to the discussion of the problems of assessing the quality of observational studies in real clinical practice and determining their place in the hierarchy of evidence-based information. The concept of “big data” and the acceptability of using such a term to refer to large observational studies is being discussed. Data on the limitations of administrative and claims databases when performing observational studies to assess the effects of interventions are presented. The concept of confounding factors influencing the results of observational studies is discussed. Modern approaches to reducing the severity of bias in real-life clinical practice studies are presented. The criteria for assessing the quality of observational pharmacoepidemiological studies and the fundamental differences between such studies and randomized clinical trials are presented. The results of systematic reviews of real-life clinical trials to assess the effects of direct oral anticoagulants are discussed.

 

SERIES: eHealth in primary care. Part 3: eHealth education in primary care

BACKGROUND

Education is essential to the integration of eHealth into primary care, but eHealth is not yet embedded in medical education.

OBJECTIVES

In this opinion article, we aim to support organisers of Continuing Professional Development (CPD) and teachers delivering medical vocational training by providing recommendations for eHealth education. First, we describe what is required to help primary care professionals and trainees learn about eHealth. Second, we elaborate on how eHealth education might be provided.

DISCUSSION

We consider four essential topics. First, an understanding of existing evidence-based eHealth applications and conditions for successful development and implementation. Second, required digital competencies of providers and patients. Third, how eHealth changes patient-provider and provider-provider relationships and finally, understanding the handling of digital data. Educational activities to address these topics include eLearning, blended learning, courses, simulation exercises, real-life practice, supervision and reflection, role modelling and community of practice learning. More specifically, a CanMEDS framework aimed at defining curriculum learning goals can support eHealth education by describing roles and required competencies. Alternatively, Kern's conceptual model can be used to design eHealth training programmes that match the educational needs of the stakeholders using eHealth.

CONCLUSION

Vocational and CPD training in General Practice needs to build on eHealth capabilities now. We strongly advise the incorporation of eHealth education into vocational training and CPD activities, rather than providing it as a separate single module. How learning goals and activities take shape and how competencies are evaluated clearly requires further practice, evaluation and study.

Association Between Race and COVID-19 Outcomes Among 2.6 Million Children in England

IMPORTANCE

Although children mainly experience mild COVID-19 disease, hospitalization rates are increasing, with limited understanding of underlying factors. There is an established association between race and severe COVID-19 outcomes in adults in England; however, whether a similar association exists in children is unclear.

OBJECTIVE

To investigate the association between race and childhood COVID-19 testing and hospital outcomes.

DESIGN, SETTING, PARTICIPANTS

In this cohort study, children (0-18 years of age) from participating family practices in England were identified in the QResearch database between January 24 and November 30, 2020. The QResearch database has individually linked patients with national SARS-CoV-2 testing, hospital admission, and mortality data.

EXPOSURES

The main characteristic of interest is self-reported race. Other exposures were age, sex, deprivation level, geographic region, household size, and comorbidities (asthma; diabetes; and cardiac, neurologic, and hematologic conditions).

MAIN OUTCOMES AND MEASURES

The primary outcome was hospital admission with confirmed COVID-19. Secondary outcomes were SARS-CoV-2-positive test result and any hospital attendance with confirmed COVID-19 and intensive care admission.

RESULTS

Of 2 576 353 children (mean [SD] age, 9.23 [5.24] years; 48.8% female), 410 726 (15.9%) were tested for SARS-CoV-2 and 26 322 (6.4%) tested positive. A total of 1853 children (0.07%) with confirmed COVID-19 attended hospital, 343 (0.01%) were admitted to the hospital, and 73 (0.002%) required intensive care. Testing varied across race. White children had the highest proportion of SARS-CoV-2 tests (223 701/1 311 041 [17.1%]), whereas Asian children (33 213/243 545 [13.6%]), Black children (7727/93 620 [8.3%]), and children of mixed or other races (18 971/147 529 [12.9%]) had lower proportions. Compared with White children, Asian children were more likely to have COVID-19 hospital admissions (adjusted odds ratio [OR], 1.62; 95% CI, 1.12-2.36), whereas Black children (adjusted OR, 1.44; 95% CI, 0.90-2.31) and children of mixed or other races (adjusted OR, 1.40; 95% CI, 0.93-2.10) had comparable hospital admissions. Asian children were more likely to be admitted to intensive care (adjusted OR, 2.11; 95% CI, 1.07-4.14), and Black children (adjusted OR, 2.31; 95% CI, 1.08-4.94) and children of mixed or other races (adjusted OR, 2.14; 95% CI, 1.25-3.65) had longer hospital admissions (≥36 hours).

CONCLUSIONS AND RELEVANCE

In this large population-based study exploring the association between race and childhood COVID-19 testing and hospital outcomes, several race-specific disparities were observed in severe COVID-19 outcomes. However, ascertainment bias and residual confounding in this cohort study should be considered before drawing any further conclusions. Overall, findings of this study have important public health implications internationally.

Measuring the Effectiveness of Real-World Evidence to Ensure Appropriate Impact

The value of real-world evidence (RWE) in medicines regulation and health technology assessment has been increasingly emphasized. Nevertheless, although RWE is increasingly used, there has been limited systematic evidence of its value. A recent study that examined the role and impact of RWE in regulatory assessments conducted through the European Medicines Agency provided such evidence. Results of the study demonstrated RWE was important to decision making, particularly for certain questions such as the quantification of adverse events, the evaluation of risk minimization measures, and the assessment of product usage. The study suggested, however, that in many of the assessments further RWE would have been valuable and concluded that RWE has, as yet, played a limited role in hypothesis generation and in the assessment of medication effectiveness. This study had been possible only because of the transparency of the European Medicines Agency decision making. Ensuring transparency of RWE evidence collection, study design and conduct, and of decision making based on this evidence will facilitate further development of the uses and value of RWE. Keywords: benefit-risk assessment; medicines regulation; real-world evidence; regulatory decision making.

Improving the Estimation of Subgroup Effects for Clinical Trial Participants with Multimorbidity by Incorporating Drug Class-Level Information in Bayesian Hierarchical Models: A Simulation Study

Background

There is limited guidance for using common drug therapies in the context of multimorbidity. In part, this is because their effectiveness for patients with specific comorbidities cannot easily be established using subgroup analyses in clinical trials. Here, we use simulations to explore the feasibility and implications of concurrently estimating effects of related drug treatments in patients with multimorbidity by partially pooling subgroup efficacy estimates across trials.

Methods

We performed simulations based on the characteristics of 161 real clinical trials of noninsulin glucose-lowering drugs for diabetes, estimating subgroup effects for patients with a hypothetical comorbidity across related trials in different scenarios using Bayesian hierarchical generalized linear models. We structured models according to an established ontology—the World Health Organization Anatomic Chemical Therapeutic Classifications—allowing us to nest all trials within drugs and all drugs within anatomic chemical therapeutic classes, with effects partially pooled at each level of the hierarchy. In a range of scenarios, we compared the performance of this model to random effects meta-analyses of all drugs individually.

Results

Hierarchical, ontology-based Bayesian models were unbiased and accurately recovered simulated comorbidity-drug interactions. Compared with single-drug meta-analyses, they offered a relative increase in precision of up to 250% in some scenarios because of information sharing across the hierarchy. Because of the relative precision of the approaches, a large proportion of small subgroup effects was detectable only using the hierarchical model.

Conclusions

By assuming that similar drugs may have similar subgroup effects, Bayesian hierarchical models based on structures defined by existing ontologies can be used to improve the precision of treatment efficacy estimates in patients with multimorbidity, with potential implications for clinical decision making.

Drug exposure misclassification in pharmacoepidemiology: Sources and relative impact

BACKGROUND

Drug exposure assessment based on dispensing data can be misclassified when patients do not adhere to their therapy or when information about over-the-counter drugs is not captured in the study database. Previous research has considered hypothetical sensitivity and specificity values, whereas this study aims to assess the impact of literature-based real values of exposure misclassification.

METHODS

A synthetic cohort study was constructed based on the proportion of exposure theoretically captured in a database (range 0.5-1.0) and the level of adherence (0.5-1.0). Three scenarios were explored: nondifferential misclassification, differential misclassification (misclassifications dependent on an unmeasured risk factor doubling the outcome risk), and nondifferential misclassification in a comparative effectiveness study (RR_A and RR_B both 2.0 compared to nonuse, RR_A-B 1.0).

RESULTS

For the scenarios with nondifferential misclassification, 25% nonadherence or 25% uncaptured exposure changed the RR from 2.0 to 1.75, and 1.95, respectively. Applying different proportions of nonadherence or uncaptured use (20% vs. 40%) for subgroups with and without the risk factor, an RR of 0.95 was observed in the absence of a true effect (i.e., true RR = 1). In the comparative effectiveness study, no effect on RR was seen for different proportions of uncaptured exposure; however, different levels of nonadherence for the drugs (20% vs. 40%) led to an underestimation of RR_A-B (0.89).

DISCUSSION

All scenarios led to biased estimates, but the magnitude of the bias differed across scenarios. When testing the robustness of findings of pharmacoepidemiologic studies, we recommend using realistic values of nonadherence and uncaptured exposure based on real-world data.

Comparison of Medication Prescribing Before and After the COVID-19 Pandemic Among Nursing Home Residents in Ontario, Canada

Importance

COVID-19 has had devastating effects on the health and well-being of older adult residents and health care professionals in nursing homes. Uncertainty about the associated consequences of these adverse effects on the use of medications common to this care setting remains.

Objective

To examine the association between the COVID-19 pandemic and prescription medication changes among nursing home residents.

Design, Setting, and Participants

This population-based cohort study with an interrupted time-series analysis used linked health administrative data bases for residents of all nursing homes (N = 630) in Ontario, Canada. During the observation period, residents were divided into consecutive weekly cohorts. The first observation week was March 5 to 11, 2017; the last observation week was September 20 to 26, 2020.

Exposures

Onset of the COVID-19 pandemic on March 1, 2020.

Main Outcomes and Measures

Weekly proportion of residents dispensed antipsychotics, benzodiazepines, antidepressants, anticonvulsants, opioids, antibiotics, angiotensin receptor blockers (ARBs), and angiotensin-converting enzyme (ACE) inhibitors. Autoregressive integrated moving average models with step and ramp intervention functions tested for level and slope changes in weekly medication use after the onset of the pandemic and were fit on prepandemic data for projected trends.

Results

Across study years, the annual cohort size ranged from 75 850 to 76 549 residents (mean [SD] age, 83.4 [10.8] years; mean proportion of women, 68.9%). A significant increased slope change in the weekly proportion of residents who were dispensed antipsychotics (parameter estimate [β] = 0.051; standard error [SE] = 0.010; P < .001), benzodiazepines (β = 0.026; SE = 0.003; P < .001), antidepressants (β = 0.046; SE = 0.013; P < .001), trazodone hydrochloride (β = 0.033; SE = 0.010; P < .001), anticonvulsants (β = 0.014; SE = 0.006; P = .03), and opioids (β = 0.038; SE = 0.007; P < .001) was observed. The absolute difference in observed vs estimated use in the last week of the pandemic period ranged from 0.48% (for anticonvulsants) to 1.52% (for antipsychotics). No significant level or slope changes were found for antibiotics, ARBs, or ACE inhibitors.

Conclusions and Relevance

In this population-based cohort study, statistically significant increases in the use of antipsychotics, benzodiazepines, antidepressants, anticonvulsants, and opioids followed the onset of the COVID-19 pandemic, although absolute differences were small. There were no significant changes for antibiotics, ARBs, or ACE inhibitors. Studies are needed to monitor whether changes in pharmacotherapy persist, regress, or accelerate during the course of the pandemic and how these changes affect resident-level outcomes.

Ten Rules for Conducting Retrospective Pharmacoepidemiological Analyses: Example COVID-19 Study

Since the beginning of the COVID-19 pandemic, pharmaceutical treatment hypotheses have abounded, each requiring careful evaluation. A randomized controlled trial generally provides the most credible evaluation of a treatment, but the efficiency and effectiveness of the trial depend on the existing evidence supporting the treatment. The researcher must therefore compile a body of evidence justifying the use of time and resources to further investigate a treatment hypothesis in a trial. An observational study can provide this evidence, but the lack of randomized exposure and the researcher's inability to control treatment administration and data collection introduce significant challenges. A proper analysis of observational health care data thus requires contributions from experts in a diverse set of topics ranging from epidemiology and causal analysis to relevant medical specialties and data sources. Here we summarize these contributions as 10 rules that serve as an end-to-end introduction to retrospective pharmacoepidemiological analyses of observational health care data using a running example of a hypothetical COVID-19 study. A detailed supplement presents a practical how-to guide for following each rule. When carefully designed and properly executed, a retrospective pharmacoepidemiological analysis framed around these rules will inform the decisions of whether and how to investigate a treatment hypothesis in a randomized controlled trial. This work has important implications for any future pandemic by prescribing what we can and should do while the world waits for global vaccine distribution.

Greater Adherence to Secondary Prevention Medications Improves Survival After Stroke or Transient Ischemic Attack: A Linked Registry Study

BACKGROUND AND PURPOSE

Although a target of 80% medication adherence is commonly cited, it is unclear whether greater adherence improves survival after stroke or transient ischemic attack (TIA). We investigated associations between medication adherence during the first year postdischarge, and mortality up to 3 years, to provide evidence-based targets for medication adherence.

METHODS

Retrospective cohort study of 1-year survivors of first-ever stroke or TIA, aged ≥18 years, from the Australian Stroke Clinical Registry (July 2010-June 2014) linked with nationwide prescription refill and mortality data (until August 2017). Adherence to antihypertensive agents, statins, and nonaspirin antithrombotic medications was based on the proportion of days covered from discharge until 1 year. Cox regression with restricted cubic splines was used to investigate nonlinear relationships between medication adherence and all-cause mortality (to 3 years postdischarge). Models were adjusted for age, sex, socioeconomic position, stroke factors, primary care factors, and concomitant medication use.

RESULTS

Among 8363 one-year survivors of first-ever stroke or TIA (44% aged ≥75 years, 44% female, 18% TIA), 75% were supplied antihypertensive agents. In patients without intracerebral hemorrhage (N=7446), 84% were supplied statins, and 65% were supplied nonaspirin antithrombotic medications. Median adherence was ≈90% for each medication group. Between 1% and 100% adherence, greater adherence to statins or antihypertensive agents, but not nonaspirin antithrombotic agents, was associated with improved survival. When restricted to linear regions above 60% adherence, each 10% increase in adherence was associated with a reduction in all-cause mortality of 13% for antihypertensive agents (hazard ratio, 0.87 [95% CI, 0.81-0.95]), 13% for statins (hazard ratio, 0.87 [95% CI, 0.80-0.95]), and 15% for nonaspirin antithrombotic agents (hazard ratio, 0.85 [95% CI, 0.79-0.93]).

CONCLUSIONS

Greater levels of medication adherence after stroke or TIA are associated with improved survival, even among patients with near-perfect adherence. Interventions to improve medication adherence are needed to maximize survival poststroke.

Nivolumab in Non-Small Cell Lung Cancer: Real World Long-Term Survival Results and Blood-Based Efficacy Biomarkers

Objectives

We aimed to examine clinical data and baseline blood test results as potential predictive biomarkers for benefit from nivolumab, in advanced non-small cell lung cancer patients (NSCLC).

Materials and Methods

A chart review was performed of 108 advanced NSCLC patients who commenced treatment with nivolumab between 2015-6 at three Israeli cancer centers, and for whom laboratory tests results were available. Data collected included sex, age, ECOG-PS, histology and number of previous lines of treatment. Baseline blood test results collected: absolute lymphocyte and neutrophil count (ANC), white blood cells (WBC), hemoglobin, platelets, albumin and lactate dehydrogenase (LDH). Neutrophil to Lymphocyte Ratio and ‘derived NLR’ (dNLR = (ANC/[WBC-ANC])) were calculated. Disease control at six months (DC6) was defined as any tumor shrinkage or stable disease during the first six months of nivolumab treatment. The association between clinical/laboratory variables and survival was tested with a Cox proportional hazard model. Data cut-off occurred in November 2019.

Results

35 patients (32.4%) achieved DC6. Median overall survival (OS) of entire study population was 5.4 months. Four year survival rate was 16%. Achievement of DC6 strongly correlated with longer OS (HR 0.12, 95% C.I. 0.07-0.21, p<0.001). In univariate and multivariate analysis, dNLR, albumin and LDH correlated significantly with OS. No variables correlated significantly with DC6 in multivariate analysis. Based on albumin and LDH, we produced a score called CLAS (combined LDH and albumin score), including four prognostic groups of patients. Patients having low albumin and high LDH had the worst prognosis.

Conclusion

In real-life setting, long-term efficacy of nivolumab in advanced line treatment of NSCLC is consistent with clinical trials. Response or stability of disease during first six months of treatment is associated with prolonged survival. We propose a novel score (CLAS) that may be useful for predicting outcome in nivolumab-treated NSCLC patients, but further validation is required.

Higher Sun Exposure in the First Trimester Is Associated With Reduced Preterm Birth; A Scottish Population Cohort Study Using Linked Maternity and Meteorological Records

Background: Preterm birth (birth at <37 weeks gestation) is the leading cause of death in children under 5-years-old, and prevention is a global public health issue. Seasonal patterns of preterm birth have been reported, but factors underlying this have been poorly described. Sun exposure is an important environmental variable that has risks and benefits for human health, but the effects of sun exposure on pregnancy duration and preterm birth are unknown. Objectives: To determine the association between available sun exposure and preterm birth. Methods: We performed a population-based data-linkage study of 556,376 singleton births (in 397,370 mothers) at or after 24 weeks gestation, in Scotland between 2000 and 2010. Maternity records were linked to available sun exposure from meteorological records, by postcode. Logistic regression analysis was used to explore the relationship between available sunshine and preterm birth at <37 weeks gestation. Exploratory analyses included a subgroup analysis of spontaneous and indicated preterm births and a sibling analysis in sib pairs discordant for preterm birth. Results: The rate of preterm birth was 6% (32,958/553,791 live births). Increased available sun exposure in the first trimester of pregnancy was associated with a reduced risk of preterm birth, with evidence of a dose-response. Compared with the lowest quartile of sun exposure, the highest quartile of sun exposure was associated with a reduced odds ratio (OR) of preterm birth of 0.90 (95% Confidence Interval (CI) 0.88-0.94 p < 0.01) on univariable analysis and OR of 0.91 (95% CI 0.87, 0.93 p < 0.01) after adjustment for second trimester sunlight exposure, parity, maternal age, smoking status, and deprivation category. No association was seen between preterm birth and second trimester available sun exposure or combined first and second trimester exposure. Similar patterns were seen on sibling analysis and within both the indicated and spontaneous preterm subgroups. Discussion: Available sun exposure in the first trimester of pregnancy is associated with a protective effect on preterm birth <37 weeks gestation. This opens up new mechanisms, and potential therapeutic pathways, for preterm birth prevention.

Influence of serum iron test results on the diagnosis of iron deficiency in children: a retrospective observational study

BACKGROUND AND OBJECTIVE

Serum iron results are not indicative of iron deficiency yet may be incorrectly used to diagnose iron deficiency instead of serum ferritin results. Our objective was to determine the association between serum iron test results and iron-deficiency diagnosis in children by general practitioners.

DESIGN, SETTING, PATIENTS AND MAIN OUTCOME MEASURES

A retrospective observational study of 14 187 children aged 1-18 years with serum ferritin and serum iron test results from 137 general practices in Victoria, Australia, between 2008 and 2018. Generalised estimating equation models calculating ORs were used to determine the association between serum iron test results (main exposure measure) and iron-deficiency diagnosis (outcome measure) in the following two population groups: (1) iron-deplete population, defined as having a serum ferritin <12 µg/L if aged <5 years and <15 µg/L if aged ≥5 years and (2) iron-replete population, defined as having a serum ferritin >30 µg/L.

RESULTS

3484 tests were iron deplete and 15 528 were iron replete. Iron-deplete children were less likely to be diagnosed with iron deficiency if they had normal serum iron levels (adjusted OR (AOR): 0.73; 95% CI 0.57 to 0.96). Iron-replete children had greater odds of an iron-deficiency diagnosis if they had low serum iron results (AOR: 2.59; 95% CI 1.72 to 3.89). Other contributors to an iron-deficiency diagnosis were female sex and having anaemia.

CONCLUSION

Serum ferritin alone remains the best means of diagnosing iron deficiency. Reliance on serum iron test results by general practitioners is leading to significant overdiagnosis and underdiagnosis of iron deficiency in children.

Prevention of delayed bleeding with vonoprazan in upper gastrointestinal endoscopic treatment

BACKGROUND

Delayed bleeding is the major adverse event in upper gastrointestinal endoscopic treatment (UGET). We aimed to investigate the efficacy of vonoprazan, which is the novel strong antisecretory agent, to reduce the risk for delayed bleeding in comparison with proton pump inhibitors (PPIs) in UGET.

METHODS

This retrospective population-based cohort study used the Diagnosis Procedure Combination database in Japan. We included patients on vonoprazan or PPI in UGET between 2014 and 2019. The primary outcome was delayed bleeding. We conducted propensity score matching to balance the comparison groups, and logistic regression analyses to compare the bleeding outcomes.

RESULTS

We enrolled 124,422 patients, in which 34,822 and 89,600 were prescribed with vonoprazan and PPI, respectively. After propensity score matching, the risk for delayed bleeding was lower in vonoprazan than in PPI (odds ratio [OR], 0.75; 95% confidence interval [CI], 0.71-0.80), consistent with sensitivity analysis results. In the subgroup analyses of seven UGET procedures, vonoprazan was significantly advantageous in esophageal endoscopic submucosal dissection (E-ESD) (OR, 0.71; 95% CI, 0.54-0.94) and gastroduodenal endoscopic submucosal dissection (GD-ESD) (OR, 0.70; 95% CI, 0.65-0.75), although correction for multiple testing of the outcome data removed the significance in E-ESD. These results were also consistent with sensitivity analysis results. In the five other procedures, no significant advantage was found.

CONCLUSIONS

This nationwide study found that, compared with PPI, vonoprazan can reduce delayed bleeding with approximately 30% in GD-ESD. Vonoprazan has the possibility to become a new treatment method for preventing delayed bleeding in this procedure.

New-user and prevalent-user designs and the definition of study time origin in pharmacoepidemiology: A review of reporting practices

BACKGROUND

Guidance reports for observational comparative effectiveness and drug safety research recommend implementing a new-user design whenever possible, since it reduces the risk of selection bias in exposure effect estimation compared to a prevalent-user design. The uptake of this guidance has not been studied extensively.

METHODS

We reviewed 89 observational effectiveness and safety cohort studies published in six pharmacoepidemiological journals in 2018 and 2019. We developed an extraction tool to assess how frequently new-user and prevalent-user designs were reported to be implemented. For studies that implemented a new-user design in both treatment arms, we extracted information about the extent to which the moment of meeting eligibility criteria, treatment initiation, and start of follow-up were reported to be aligned.

RESULTS

Of the 89 studies included, 40% reported implementing a new-user design for both the study exposure arm and the comparator arm, while 13% reported implementing a prevalent-user design in both arms. The moment of meeting eligibility criteria, treatment initiation, and start of follow-up were reported to be aligned in both treatment arms in 53% of studies that reported implementing a new-user design. We provided examples of studies that minimized the risk of introducing bias due to unclear definition of time origin in unexposed participants, immortal time, or a time lag.

CONCLUSIONS

Almost half of the included studies reported implementing a new-user design. Implications of misalignment of study design origin were difficult to assess because it would require explicit reporting of the target estimand in original studies. We recommend that the choice for a particular study time origin is explicitly motivated to enable assessment of validity of the study.

Drug Safety in Translational Paediatric Research: Practical Points to Consider for Paediatric Safety Profiling and Protocol Development: A Scoping Review

Translational paediatric drug development includes the exchange between basic, clinical and population-based research to improve the health of children. This includes the assessment of treatment related risks and their management. The objectives of this scoping review were to search and summarise the literature for practical guidance on how to establish a paediatric safety specification and its integration into a paediatric protocol. PubMed, Embase, Web of Science, and websites of regulatory authorities and learned societies were searched (up to 31 December 2020). Retrieved citations were screened and full texts reviewed where applicable. A total of 3480 publications were retrieved. No article was identified providing practical guidance. An introduction to the practical aspects of paediatric safety profiling and protocol development is provided by combining health authority and learned society guidelines with the specifics of paediatric research. The paediatric safety specification informs paediatric protocol development by, for example, highlighting the need for a pharmacokinetic study prior to a paediatric trial. It also informs safety related protocol sections such as exclusion criteria, safety monitoring and risk management. In conclusion, safety related protocol sections require an understanding of the paediatric safety specification. Safety data from carefully planned paediatric research provide valuable information for children, parents and healthcare providers.

A systematic review of how missing data are handled and reported in multi-database pharmacoepidemiologic studies

Purpose

Pharmacoepidemiologic multi‐database studies (MDBS) provide opportunities to better evaluate the safety and effectiveness of medicines. However, the issue of missing data is often exacerbated in MDBS, potentially resulting in bias and precision loss. We sought to measure how missing data are being recorded and addressed in pharmacoepidemiologic MDBS.

Methods

We conducted a systematic literature search in PubMed for pharmacoepidemiologic MDBS published between 1st January 2018 and 31st December 2019. Included studies were those that used ≥2 distinct databases to assess the same safety/effectiveness outcome associated with a drug exposure. Outcome variables extracted from the studies included strategies to execute a MDBS, reporting of missing data (type, bias evaluation) and the methods used to account for missing data.

Results

Two thousand seven hundred and twenty‐six articles were identified, and 62 studies were included: using data from either North America (56%), Europe (31%), multiple regions (11%) or East‐Asia (2%). Thirty‐five (56%) articles reported missing data: 11 of these studies reported that this could have introduced bias and 19 studies reported a method to address missing data. Thirteen (68%) carried out a complete case analysis, 2 (11%) applied multiple imputation, 2 (11%) used both methods, 1 (5%) used mean imputation and 1 (5%) substituted information from a similar variable.

Conclusions

Just over half of the recent pharmacoepidemiologic MDBS reported missing data and two‐thirds of these studies reported how they accounted for it. We should increase our vigilance for database completeness in MDBS by reporting and addressing the missing data that could introduce bias.

Association of Low-Dose Quetiapine and Diabetes

IMPORTANCE

Quetiapine has been associated with increased risk of type 2 diabetes when used in medium or high doses for the treatment of severe mental disorders. It is not known whether low doses, commonly used off-label for sedative-hypnotic purposes, are also associated with increased risk of type 2 diabetes.

OBJECTIVE

To investigate whether there is an association between prescription of low-dose quetiapine and the risk of type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined nationwide Danish health registers for data regarding new users of quetiapine (n = 185 938) or selective serotonin reuptake inhibitors (SSRIs) (n = 1 031 920) who were aged 18 years or older between January 1, 1998, and December 31, 2018. Individuals with schizophrenia or bipolar disorder were excluded. Quetiapine-initiators were matched 1:1 with initiators of SSRIs, using a high-dimensional propensity score (hdPS). Maximum follow-up was 5 years. Association with cumulative dose was investigated, using a case-control approach nested among quetiapine users. Data analysis was performed from May to September 2020.

EXPOSURES

Dispensing of quetiapine or SSRIs. Quetiapine prescriptions were limited to tablet strengths of 25 mg and 50 mg to focus on low-dose use.

MAIN OUTCOMES AND MEASURES

Incident type 2 diabetes was defined as first filling of an antidiabetic medication, first register diagnosis of type 2 diabetes or first hemoglobin A1C measurement greater than or equal to 6.4% (≥48 mmol/mol). Incidence rates (IRs), incidence rate ratios (IRRs), and number-needed-to-harm (NNH) were calculated for full and matched cohorts using as-treated and intention-to-treat approaches. Odds ratios (ORs) were calculated for the association with cumulative quetiapine dose.

RESULTS

Altogether, 896 285 patients were included in the full cohort; 538 164 (60%) were female and the median (interquartile range) age was 47 (33-67) years. There were 57 701 low-dose quetiapine initiators and 838 584 SSRI initiators. The matched cohort consisted of 54 616 pairs. In as-treated analyses, the incidence of type 2 diabetes during treatment with low-dose quetiapine (425 cases) was 9.59 cases/1000 person-years (PY) (95% CI, 8.72-10.5/1000 PY), which was slightly higher than for SSRI users (8462 cases; IR, 8.13/1000 PY; 95% CI, 7.96-8.30/1000 PY), resulting in a significant IRR of 1.18 (95% CI, 1.07-1.30) and NNH of 684 (95% CI, 418-1873). However, the between-group difference was nonsignificant in the hdPS-matched cohort (IR, 9.49 vs IR, 9.58; IRR, 0.99; 95% CI, 0.87-1.13). The case-control analysis found no dose-response association of low-dose quetiapine with diabetes (OR for doubling of the cumulative dose: 1.02; 95% CI, 0.95-1.09; P = .54), but in sensitivity analyses higher daily doses were associated with diabetes (all tablet strengths: OR, 1.08; 95% CI, 1.03-1.13).

CONCLUSIONS AND RELEVANCE

In this cohort study, use of low-dose quetiapine was not associated with excess risk of type 2 diabetes in comparison with SSRIs.

Organized structure of real-world evidence best practices: moving from fragmented recommendations to comprehensive guidance

Decision-makers have become increasingly interested in incorporating real-world evidence (RWE) into their decision-making process. Due to concerns regarding the reliability and quality of RWE, stakeholders have issued numerous recommendation documents to assist in setting RWE standards. The fragmented nature of these documents poses a challenge to researchers and decision-makers looking for guidance on what is 'high-quality' RWE and how it can be used in decision-making. We offer researchers and decision-makers a structure to organize the landscape of RWE recommendations and identify consensus and gaps in the current recommendations. To provide researchers with a much needed pathway for generating RWE, we discuss how decision-makers can move from fragmented recommendations to comprehensive guidance.

Trends in Australian dental prescribing of antibiotics: 2005-2016

BACKGROUND

Prescribing of antibiotics by dentists for surgical prophylaxis or as an adjunct to managing dental infections is a substantial part of the overall landscape for prescribed antibiotics in health care settings.

METHODS

We explored trends in the antibiotic prescribing patterns of Australian dentists over the 12-year period, 2005-2016. We obtained data on dispensed prescriptions of antibiotics from registered dentists subsidized on the Pharmaceutical Benefits Scheme.

RESULTS

Australian dentists were responsible for almost 7 million dispensed prescriptions of antibiotics over 12 years; an average of 24 prescriptions per year per dentist. The most commonly prescribed antibiotic was amoxicillin, followed by amoxicillin + clavulanic acid and metronidazole. These top three antibiotics constituted more than 80% of all antibiotics prescribed and their use increased dramatically over time. There was a large increase in the prescribing of broad-spectrum antibiotics over time, most of which occurred from 2011 to 2016.

CONCLUSIONS

Excessive prescribing of broad-spectrum antibiotics runs contrary to national antimicrobial stewardship (AMS) initiatives and guidelines. Multifaceted educational strategies are essential to align prescribing with current best practice. High-level evidence to inform clear guidelines on antibiotic prescribing in dental infections, with audit and feedback, should reduce the inappropriate use of antibiotics in dentistry.

Association between antihypertensive medications and risk of skin cancer in people older than 65 years: a population-based study

BACKGROUND:

The risk of skin cancer associated with antihypertensive medication use is unclear, although thiazides have been implicated in regulatory safety warnings. We aimed to assess whether use of thiazides and other antihypertensives is associated with increased rates of keratinocyte carcinoma and melanoma.

METHODS:

We conducted a population-based inception cohort study using linked administrative health data from Ontario, 1998–2017. We matched adults aged ≥ 66 years with a first prescription for an antihypertensive medication (thiazides, angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, calcium channel blockers, β-blockers) by age and sex to 2 unexposed adults who were prescribed a non-antihypertensive medication within 30 days of the index date. We evaluated each antihypertensive class in a separate cohort study. Our primary exposure was the cumulative dose within each class, standardized according to the World Health Organization’s Defined Daily Dose. Outcomes were time to first keratinocyte carcinoma, advanced keratinocyte carcinoma and melanoma.

RESULTS:

The inception cohorts included a total of 302 634 adults prescribed an antihypertensive medication and 605 268 unexposed adults. Increasing thiazide exposure was associated with an increased rate of incident keratinocyte carcinoma (adjusted hazard ratios [HRs] per 1 Defined Annual Dose unit 1.08, 95% confidence interval [CI] 1.03–1.14), advanced keratinocyte carcinoma (adjusted HR 1.07, 95% CI 0.93–1.23) and melanoma (adjusted HR 1.34, 95% CI 1.01–1.78). We found no consistent evidence of association between other antihypertensive classes and keratinocyte carcinoma or melanoma.

INTERPRETATION:

Higher cumulative exposure to thiazides was associated with increased rates of incident skin cancer in people aged 66 years and older. Consideration of other antihypertensive treatments in patients at high risk of skin cancer may be warranted.