Nirmatrelvir-Ritonavir and COVID-19 Mortality and Hospitalization Among Patients With Vulnerability to COVID-19 Complications.

Importance: Postmarket analysis of individuals who receive nirmatrelvir and ritonavir (Paxlovid [Pfizer]) is essential because they differ substantially from individuals included in published clinical trials. Objective: To examine the association of nirmatrelvir and ritonavir with prevention of death or admission to hospital in individuals with different risks of complications from COVID-19 infection. Design, Setting, and Participants: This is a cohort study of adult patients in British Columbia, Canada, between February 1, 2022, and February 3, 2023. Patients were eligible if they belonged to 1 of 4 higher-risk groups of individuals who received priority for COVID-19 vaccination. Two groups included clinically extremely vulnerable (CEV) people who were severely (CEV1) or moderately immunocompromised (CEV2). CEV3 individuals were not immunocompromised but had medical conditions associated with a high risk for complications from COVID-19. A fourth expanded eligibility (EXEL) group was added to allow wider access to nirmatrelvir and ritonavir for certain other higher-risk individuals who were not in a CEV group, such as those older than 70 years who were unvaccinated. Exposures: Patients with COVID-19 who received nirmatrelvir and ritonavir were matched to patients in the same vulnerability group; who were of the same sex, age, and propensity score for nirmatrelvir and ritonavir treatment; and who were also infected within 1 month of the individual treated with nirmatrelvir and ritonavir. Main Outcomes and Measures: The primary outcome was death from any cause or emergency hospitalization with COVID-19 within 28 days. Results: There were 6866 individuals included in the study, of whom 3888 (56.6%) were female and whose median (IQR) age was 70 (57-80) years. Compared with unexposed controls, treatment with nirmatrelvir and ritonavir was associated with statistically significant relative reductions in the primary outcome in the CEV1 group (560 patients; risk difference [RD], -2.5%, 95% CI, -4.8% to -0.2%) and the CEV2 group (2628 patients; RD, -1.7%; 95% CI, -2.9% to -0.5%). In the CEV3 group, the RD was -1.3%, but the findings were not statistically significant (2100 patients; 95% CI, -2.8% to 0.1%). In the EXEL group, treatment was associated with higher risk of the outcome (RD, 1.0%), but the findings were not statistically significant (1578 patients; 95% CI, -0.9% to 2.9%). Conclusions and Relevance: In this cohort study of 6866 individuals in British Columbia, nirmatrelvir and ritonavir treatment was associated with reduced risk of COVID-19 hospitalization or death in CEV individuals, with the greatest benefit observed in severely immunocompromised individuals. No reduction in the primary outcome was observed in lower-risk individuals, including those aged 70 years or older without serious comorbidities.

Validity of diagnoses of SARS-CoV-2 infection in Canadian administrative health data: a multiprovince, population-based cohort study.

BACKGROUND: Accurate coding of diagnoses of SARS-CoV-2 infection in administrative data benefits population-based studies about the epidemiology, treatment and outcomes of COVID-19. We describe the validity of diagnoses of SARS-CoV-2 infection recorded in hospital discharge abstracts, emergency department records and outpatient physician service claims from 3 Canadian provinces. METHODS: In this cohort study, population-based inpatient, emergency department and outpatient records were linked to SARS-CoV-2 polymerase chain reaction (PCR; reference standard) test results from British Columbia, Manitoba and Ontario for Apr. 1, 2020, to Mar. 31, 2021. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of diagnoses of SARS-CoV-2 infection were estimated for each quarter in the study period, overall and by province, age group and sex. RESULTS: Our study encompassed more than 13 million SARS-CoV-2 PCR test results. Specificity and NPV of diagnoses of SARS-CoV-2 infection were consistently high (i.e., most estimates were > 95%). Overall sensitivity estimates were 86.2%, 60.4% and 20.3% in the first quarter for inpatient, emergency department and outpatient cohorts, and 66.2%, 47.5% and 25.0% in the last quarter, respectively. For inpatients, overall PPV estimates ranged from 50.0% to 66.4%. For emergency department patients, overall PPV estimates were 76.9% and 68.3% in the first and last quarters, respectively. For outpatients, PPV estimates were 6.8% and 29.1% in the first and last quarters, respectively. INTERPRETATION: We found variations in the validity of diagnoses for SARS-CoV-2 infection recorded in different health care settings, geographic areas and over time. Our multiprovince validation study provides evidence about the potential use of inpatient and emergency department records as an alternative to population-based laboratory data for identification of patients with SARS-CoV-2 infection, but does not support the use of outpatient claims for this purpose.

Trends in antihypertensive drug utilization in British Columbia, 2004-2019: a descriptive study.

BACKGROUND: Clinical guidelines for hypertension were updated with lower blood pressure targets following new studies in 2015; the real-world impact of these changes on antihypertensive drug use is unknown. We aimed to describe trends in antihypertensive drug utilization from 2004 to 2019 in British Columbia. METHODS: We conducted a longitudinal study to describe the annual prevalence and incidence rate of use of 5 antihypertensive drug classes (thiazides, angiotensin-converting enzyme [ACE] inhibitors, angiotensin II receptor blockers [ARBs], calcium channel blockers and ß-blockers) among BC residents aged 30-75 years. We also conducted a cohort study to compare the risk of discontinuation and switch or add-on therapy between incident users of the above drug classes. We used linkable administrative health databases from BC. We performed a Fine-Gray competing risk analysis to estimate subhazard ratios. RESULTS: Among BC residents aged 30-75 years (population: 2 376 282 [2004] to 3 014 273 [2019]), the incidence rate of antihypertensive drug use decreased from 23.7 per 1000 person-years in 2004 to 18.3 per 1000 person-years in 2014, and subsequently increased to 22.6 per 1000 person-years in 2019. The incidence rate of thiazide use decreased from 8.9 per 1000 person-years in 2004 to 3.2 per 1000 person-years in 2019, and incidence rates for the other drug classes increased. Incident users receiving thiazide monotherapy had an increased risk of discontinuing any antihypertensive treatment compared with ACE inhibitor monotherapy (subhazard ratio 0.96, 95% confidence interval [CI] 0.95-0.97), ARB monotherapy (subhazard ratio 0.84, 95% CI 0.81-0.87) and thiazide combination with ACE inhibitor or ARB (subhazard ratio 0.86, 95% CI 0.84-0.88), and had the highest risk of switching or adding on. INTERPRETATION: First-line use of thiazides continued to decrease despite a marked increase in incident antihypertensive therapy following updated guidelines; incident users receiving ARB monotherapy were least likely to discontinue, and incident users receiving thiazide monotherapy were more likely to switch or add on than users of other initial monotherapy or combination. Further research is needed on the factors influencing treatment decisions to understand the differences in trends and patterns of antihypertensive drug use.

A cluster randomized trial assessing the impact of personalized prescribing feedback on antibiotic prescribing for uncomplicated acute cystitis to family physicians.

OBJECTIVE: To evaluate the impact of personalized prescribing portraits on antibiotic prescribing for treating uncomplicated acute cystitis (UAC) by Family Physicians (FPs). DESIGN: Cluster randomized control trial. SETTING: The intervention was conducted in the primary care setting in the province of BC between December 2010 and February 2012. PARTICIPANTS: We randomized 4 833 FPs by geographic location into an Early intervention arm (n = 2 417) and a Delayed control arm (n = 2 416). INTERVENTION: The Education for Quality Improvement in Patient Care (EQIP) program mailed to each FP in BC, a 'portrait' of their individual prescribing of antibiotics to women with UAC, plus therapeutic recommendations and a chart of trends in antibiotic resistance. MAIN OUTCOME MEASURES: Antibiotic prescribing preference to treat UAC. RESULTS: Implementing exclusion criteria before and after a data system change in the Ministry of Health caused the arms to be unequal in size-intervention arm (1 026 FPs, 17 637 UAC cases); control arm (1 352 FPs, 25 566 UAC cases)-but they were well balanced by age, sex and prior rates of prescribing antibiotics for UAC. In the early intervention group probability of prescribing nitrofurantoin increased from 28% in 2010 to 38% in 2011, a difference of 9.9% (95% confidence interval [CI], 9.1% to 10.7. Ciprofloxacin decreased by 6.2% (95% CI: 5.6% to 6.9%) and TMP-SMX by 3.7% (95% CI: 3.1% to 4.2%). Among 295 FPs who completed reflective surveys, 52% said they were surprized by the E. coli resistance statistics and 57% said they planned to change their treatment of UAC. CONCLUSION: The EQIP intervention demonstrated that feedback of personal data to FPs on their prescribing, plus population data on antibiotic resistance, with a simple therapeutic recommendation, can significantly improve prescribing of antibiotics. Trial registration: ISRCTN 16938907.

Monitoring a Mandatory Nonmedical Switching Policy from Originator to Biosimilar Infliximab in Patients with Inflammatory Bowel Diseases: A Population-Based Cohort Study.

Background: On September 5, 2019, British Columbia announced a new policy (the Biosimilars Initiative) to switch from originator to biosimilar infliximab for patients with inflammatory bowel diseases. Objective: To monitor the impacts of the policy on the use of medications and health services during the first year of the policy. Methods: In this population-based cohort study, we used administrative health data to construct three historical cohorts and one policy cohort of patients with inflammatory bowel diseases who used the originator infliximab. We then monitored the cumulative incidence of medications and health services. Log-likelihood ratios were used to quantify differences between the policy cohort and the average of the historical cohorts. Results: The cohorts included 1839-2368 users of the originator infliximab, ages 4-90 years, mean age 43 years. During the first year of follow-up, we found: (1) a 0.9% increase in the first dispensation of infliximab, biosimilar, or originator; (2) a 16.2% increase in infliximab dose escalation; (3) a decrease of 2.4% in the dispensation of antibiotics and a 2.6% decrease in new use of prednison; (4) an anticipated increase in visits to physicians and gastroenterologists to manage switching to biosimilars (24.0%); (5) a 4.0% decrease in discharges from hospital; and (6) a 2.9% decrease in emergency admissions to hospital. Conclusion: British Columbia's Biosimilars Initiative for nonmedical switching from originator to biosimilar infliximab for inflammatory bowel diseases was not associated with harmful impacts on medications and health services use. An increase in dose escalation was accompanied by an improvement in health status proxies.

Public reporting of clinical trial findings as an ethical responsibility to participants: a qualitative study.

OBJECTIVE: To understand how the experiences and views of trial participants, trial investigators and others connected to clinical trial research relate to whether researchers have a duty to participants to publicly report research findings. DESIGN: Qualitative interview study. SETTING: Semistructured interviews held in person or by telephone between March 2019 and April 2021 with participants in the Canadian provinces of Alberta, British Columbia and Ontario. PARTICIPANTS: 34 participants, including 10 clinical trial participants, 17 clinical trial investigators, 1 clinical research coordinator, 3 research administrators and 3 research ethics board members. ANALYSIS: We conducted a thematic analysis, including qualitative coding of interview transcripts and identification of key themes. MAIN OUTCOME MEASURES: Key themes identified through qualitative coding of interview data. RESULTS: Most clinical trial participants felt that reporting clinical trial results is important. Accounts of trial participants suggest their contributions are part of a reciprocal relationship involving the expectation that research will advance medical knowledge. Similarly, comments from trial investigators suggest that reporting trial results is part of reciprocity with trial participants and is a necessary part of honouring informed consent. Accounts of trial investigators suggest that when drug trials are not reported, this may undermine informed consent in subsequent trials by withholding information on harms or efficacy relevant to informed decisions on whether to conduct or enroll in future trials of similar drugs. CONCLUSION: The views of trial participants, trial investigators and others connected to clinical trial research in Canada suggest that researchers have an obligation to participants to publicly report clinical trial results and that reporting results is necessary for honouring informed consent.

Factors relating to nonpublication and publication bias in clinical trials in Canada: A qualitative interview study.

AIMS: This study aims to understand factors contributing to nonpublication and publication bias in clinical trials in Canada. METHODS: Qualitative interviews were conducted between March 2019 and April 2021 with 34 participants from the Canadian provinces of Alberta, British Columbia and Ontario, including 17 clinical trial investigators, 1 clinical research coordinator, 3 research administrators, 3 research ethics board members and 10 clinical trial participants. We conducted a thematic analysis involving coding of interview transcripts and memo-writing to identify key themes. RESULTS: Several factors contribute to nonpublication and publication bias in clinical trial research. A core theme was that reporting practices are shaped by incentives within the research system taht favour publication of positive over negative trials. Investigators are discouraged from reporting by experiences or perceptions of difficulty in publishing negative findings but rewarded for publishing positive findings in various ways. Trial investigators more strongly associated positive clinical trials than negative trials with opportunities for industry and nonindustry funding and with academic promotion, bonuses and recognition. Research institutions and ethics boards tended to lack well-resourced, proactive policies and practices to ensure trial findings are reported in registries or journals. CONCLUSION: Clinical trial reporting practices in Canada are shaped by incentives favouring reporting of positive over negative trials, such as funding opportunities and academic promotion, bonuses and recognition. Research institutions could help change incentives by adopting performance metrics that emphasize full reporting of results in journals or registries.

Patterns of antiemetic medication use during pregnancy: A multi-country retrospective cohort study.

OBJECTIVE: To compare patterns in use of different antiemetics during pregnancy in Canada, the United Kingdom, and the United States, between 2002 and 2014. METHODS: We constructed population-based cohorts of pregnant women using administrative healthcare data from five Canadian provinces (Alberta, British Columbia, Manitoba, Ontario, and Saskatchewan), the Clinical Practice Research Datalink from the United Kingdom, and the IBM MarketScan Research Databases from the United States. We included pregnancies ending in live births, stillbirth, spontaneous abortion, or induced abortion. We determined maternal use of antiemetics from pharmacy claims in Canada and the United States and from prescriptions in the United Kingdom. RESULTS: The most common outcome of 3 848 734 included pregnancies (started 2002-2014) was live birth (66.7% of all pregnancies) followed by spontaneous abortion (20.2%). Use of antiemetics during pregnancy increased over time in all three countries. Canada had the highest prevalence of use of prescription antiemetics during pregnancy (17.7% of pregnancies overall, 13.2% of pregnancies in 2002, and 18.9% in 2014), followed by the United States (14.0% overall, 8.9% in 2007, and 18.1% in 2014), and the United Kingdom (5.0% overall, 4.2% in 2002, and 6.5% in 2014). Besides use of antiemetic drugs being considerably lower in the United Kingdom, the increase in its use over time was more modest. The most commonly used antiemetic was combination doxylamine/pyridoxine in Canada (95.2% of pregnancies treated with antiemetics), ondansetron in the United States (72.2%), and prochlorperazine in the United Kingdom (63.5%). CONCLUSIONS: In this large cohort study, we observed an overall increase in antiemetic use during pregnancy, and patterns of use varied across jurisdictions. Continued monitoring of antiemetic use and further research are warranted to better understand the reasons for differences in use of these medications and to assess their benefit-risk profile in this population.

Treatment pattern trends of medications for type 2 diabetes in British Columbia, Canada.

INTRODUCTION: Several new oral drug classes for type 2 diabetes (T2DM) have been introduced in the last 20 years accompanied by developments in clinical evidence and guidelines. The uptake of new therapies and contemporary use of blood glucose-lowering drugs has not been closely examined in Canada. The objective of this project was to describe these treatment patterns and relate them to changes in provincial practice guidelines. RESEARCH DESIGN AND METHODS: We conducted a longitudinal drug utilization study among persons with T2DM aged ≥18 years from 2001 to 2020 in British Columbia (BC), Canada. We used dispensing data from community pharmacies with linkable physician billing and hospital admission records. Laboratory results were available from 2011 onwards. We identified incident users of blood glucose-lowering drugs, then determined sequence patterns of medications dispensed, with stratification by age group, and subgroup analysis for patients with a history of cardiovascular disease. RESULTS: Among a cohort of 362 391 patients (mean age 57.7 years old, 53.5% male) treated for non-insulin-dependent diabetes, the proportion who received metformin monotherapy as first-line treatment reached a maximum of 90% in 2009, decreasing to 73% in 2020. The proportion of patients starting two-drug combinations nearly doubled from 3.3% to 6.4%. Sulfonylureas were the preferred class of second-line agents over the course of the study period. In 2020, sodium-glucose cotransporter type 2 inhibitors and glucagon-like peptide-1 receptor agonists accounted for 21% and 10% of second-line prescribing, respectively. For patients with baseline glycated hemoglobin (A1C) results prior to initiating diabetic treatment, 41% had a value ≤7.0% and 27% had a value over 8.5%. CONCLUSIONS: Oral diabetic medication patterns have changed significantly over the last 20 years in BC, primarily in terms of medications used as second-line therapy. Over 40% of patients with available laboratory results initiated T2DM treatment with an A1C value ≤7.0%, with the average A1C value trending lower over the last decade.

How do safety warnings on medicines affect prescribing?

INTRODUCTION: Many adverse effects of medicines only become known after approval, prompting regulatory agencies to issue post-market safety advisories to support safer care. Our team evaluated advisories issued by national regulators in Australia, Canada, Denmark, the United Kingdom, and the United States from 2007 to 2016 inclusive, comparing regulators' decisions to warn, effects on prescribing, doctors' awareness and responses to warnings, relevant regulatory policies, and specific case studies. AREAS COVERED: Based mainly on our research program and a narrative review, this commentary describes how often regulators issue safety advisories and effects on clinical practice. We found extensive differences in decisions to warn, timing and content of warnings. Monitoring advice is often inadequate. The most systematic estimate suggests an average reduction in prescribing of around 6% compared with settings with no advisory. Interviews with doctors suggest limited awareness, uptake, and at times belief in these warnings. EXPERT OPINION: Post-market safety advisories are an important intervention aiming to improve prescribing and use of medicines. However, differing warnings mean that some patients may be exposed to riskier prescribing than others. Better integration of safety information into clinical practice is needed, as well as improved transparency, independence, and public engagement in regulatory decision-making.

Pioglitazone use in Australia and the United Kingdom following drug safety advisories on bladder cancer risk: An interrupted time series study.

PURPOSE: National regulators in Australia and the United Kingdom issued safety advisories on the association between pioglitazone use and bladder cancer in July 2011. The Australian advisory noted that males were at higher risk of bladder cancer than females, while the UK advisory highlighted a new recommendation, suggest careful consideration in the elderly due to increasing risk with age. This study examined whether these differences in the advisories had different age- and sex-based impacts in each country. METHODS: Interrupted time series analysis was used to compare pioglitazone use (prescriptions/100000 population) in Australia and the United Kingdom for the 24 months before and 11 months after the July 2011 safety advisories (study period July 2009-June 2012). Separate models were used to compare use by sex and age group (≥65 years vs. <65 years) in each country. RESULTS: Pioglitazone use fell in Australia (17%) and the United Kingdom (24%) following the safety advisories. Use of pioglitazone fell more for males (18%) than females (16%) in Australia, and more for females (25%) than males (23%) in the United Kingdom; however, neither difference was statistically significant (Australia p = 0.445, United Kingdom p = 0.462). Pioglitazone use fell to a similar extent among older people than younger people in the United Kingdom (23% vs. 26%, p = 0.354), and did not differ between age groups in Australia (both 18%, p = 0.772). CONCLUSIONS: The results indicate that differences in the Australian and UK safety advisories resulted in substantial reductions in pioglitazone use at the population level in both countries, however, differences by sub-groups were not observed.

Hydroxyzine Initiation Following Drug Safety Advisories on Cardiac Arrhythmias in the UK and Canada: A Longitudinal Cohort Study.

INTRODUCTION: Regulatory advisories on hydroxyzine and risk of QT prolongation and Torsade de pointes (TdP) were issued in the UK in April 2015 and Canada in June 2016. We hypothesized patients with risk factors for QT prolongation and TdP, compared with those without risk factors, would be less likely to initiate hydroxyzine in the UK and in British Columbia (BC), Canada, following advisories. METHODS: We conducted a longitudinal study with repeated measures, and evaluated hydroxyzine initiation in a UK cohort and a concurrent BC control cohort (April 2013-March 2016) as well as in a BC advisory cohort (June 2014-May 2017). RESULTS: This study included 247,665 patients in the UK cohort, 297,147 patients in the BC control cohort, and 303,653 patients in the BC advisory cohort. Over a 12-month post-advisory period, hydroxyzine initiation decreased by 21% in the UK (rate ratio 0.79, 95% confidence interval 0.66-0.96) relative to the expected level of initiation based on the pre-advisory trend. Hydroxyzine initiation did not change in the BC control cohort or following the Canadian advisory in the BC advisory cohort. The decrease in hydroxyzine initiation in the UK in the 12 months after the advisories was not significantly different for patients with risk factors compared with those without risk factors. CONCLUSION: Hydroxyzine initiation decreased in the UK, but not in BC, in the 12 months following safety advisories. The decrease in hydroxyzine initiation in the UK was not significantly different for patients with versus without risk factors for QT prolongation and TdP.

Mandatory nonmedical switching from originator to biosimilar infliximab in patients with inflammatory arthritis and psoriasis in British Columbia: a cohort study.

BACKGROUND: In 2019, British Columbia's public drug plan, PharmaCare, was the first in Canada to implement a nonmedical switching policy from originator infliximab to its biosimilar, for patients with inflammatory arthritis or psoriasis. We aimed to detect signals of impact on health services utilization during the first year of policy implementation and to provide early data to policy-makers. METHODS: We constructed cohorts of users of originator infliximab: 3 historical cohorts (2016-2018) and 1 policy cohort (2019). We extracted data from BC Ministry of Health databases from 2015 to 2020, as we followed each cohort for 365 days from May 27 of each cohort's respective year. We excluded patients with gastrointestinal conditions and those not covered by PharmaCare. We examined the cumulative incidence of infliximab prescription refills, switching to other biologic drugs and use of additional health services. A log-likelihood ratio of 1.96 compared with the null hypothesis was used as the threshold for differences between the policy cohort and the historical cohorts. RESULTS: The study included a total of 572 unique patients: 520 in the 2016 historical cohort, 461 in the 2017 historical cohort, 423 in the 2018 historical cohort and 377 in the policy cohort (with some patients included in multiple cohorts; 335 [58.6%] were included in all 4 cohorts). During months 8 and 9 of follow-up, a transient signal was observed in infliximab refills (7.2% decrease in refilling infliximab for the fourth time for the policy cohort, log-likelihood ratio > 1.96). An anticipated increase in visits to specialists was observed from month 4 forward (15.0%, log-likelihood ratio > 1.96). No signal was observed for increased use of other health services (log-likelihood ratio < 1.96). INTERPRETATION: Early monitoring did not detect signals of negative impacts on health services use during the first year of the policy. Detailed, longer-term cohort studies and hypothesis-testing methods could provide additional assurance about the safety of the policy.

Influence of drug safety advisories on drug utilisation: an international interrupted time series and meta-analysis.

OBJECTIVE: To evaluate the association between regulatory drug safety advisories and changes in drug utilisation. DESIGN: We conducted controlled, interrupted times series analyses with administrative prescription claims data to estimate changes in drug utilisation following advisories. We used random-effects meta-analysis with inverse-variance weighting to estimate the average postadvisory change in drug utilisation across advisories. STUDY POPULATION: We included advisories issued in Canada, Denmark, the UK and the USA during 2009-2015, mainly concerning drugs in common use in primary care. We excluded advisories related to over-the-counter drugs, drug-drug interactions, vaccines, drugs used primarily in hospital and advisories with co-interventions within ±6 months. MAIN OUTCOME MEASURES: Change in drug utilisation, defined as actual versus predicted percentage change in the number of prescriptions (for advisories without dose-related advice), or in the number of defined daily doses (for dose-related advisories), per 100 000 population. RESULTS: Among advisories without dose-related advice (n=20), the average change in drug utilisation was -5.83% (95% CI -10.93 to -0.73; p=0.03). Advisories with dose-related advice (n=4) were not associated with a statistically significant change in drug utilisation (-1.93%; 95% CI -17.10 to 13.23; p=0.80). In a post hoc subgroup analysis of advisories without dose-related advice, we observed no statistically significant difference between the change in drug utilisation following advisories with explicit prescribing advice, such as a recommendation to consider the risk of a drug when prescribing, and the change in drug utilisation following advisories without such advice. CONCLUSIONS: Among safety advisories issued on a wide range of drugs during 2009-2015 in 4 countries (Canada, Denmark, the UK and the USA), the association of advisories with changes in drug utilisation was variable, and the average association was modest.

Industry Sponsor Influence in Clinical Trial Reporting in Canada: A Qualitative Interview Study.

PURPOSE: Approximately 40% of randomized controlled trials are not published, leading to publication bias and less informed clinical decision-making. Qualitative interviews were conducted to understand whether and how industry sponsors of clinical trials of drugs and biologics in Canada influence decisions to report trial results. METHODS: Participants eligible for an interview included clinical trial investigators and research coordinators with experience in drug research, research ethics board members with at least 1 year of experience in ethical review of trials, research administrators with knowledge of dissemination of clinical trial findings or relations with trial sponsors, and trial participants who had taken part in a drug trial as an adult in the 5 years before their interview. Semi-structured interviews were held in person or by telephone between March 2019 and April 2021 with participants in Alberta, British Columbia, and Ontario, Canada. Qualitative analysis included coding of interview transcripts and identification of key themes. FINDINGS: Interviews were conducted with 34 participants, including 17 clinical trial investigators, 1 clinical research coordinator, 3 research administrators, 3 research ethics board members, and 10 clinical trial participants. Participants involved in the conduct, administration, or ethical review of trials represented a range of medical disciplines. Interview participant accounts indicated that in some cases, industry sponsors influence whether results are reported. A core theme was that companies have a weaker incentive to publish trials with unfavorable findings and trials for products that they have decided not to develop further. Companies may influence reporting in various ways, including stopping trials early and not reporting results of stopped trials, owning and controlling access to data, and negotiating clinical trial agreements in multicenter trials that do not fully protect the ability of investigators to publish. Internal company trials represent an additional source of unpublished trials. More broadly, the research system creates a dependency on funding from industry sponsors that may weaken the ability of researchers and research institutions to negotiate terms with industry sponsors that would fully protect publication rights. IMPLICATIONS: Interviews with trial investigators and others connected to trial research indicate that in some cases, industry sponsors of clinical trial research in Canada influence whether results are reported. Policies aiming to bring about full reporting of trials could benefit from considering the commercial incentives of companies and the ways in which industry sponsors may influence clinical trial reporting. Future research could examine the generalizability of these findings to other jurisdictions.

Impact of using concomitant conventional DMARDs on adherence to biologic DMARD treatment in rheumatoid arthritis: Multi-centre, population-based cohort study.

PURPOSE: To evaluate the impact of concomitant use of conventional synthetic DMARDs (csCMARD) on adherence, switching and dose of biologic disease modifying antirheumatic drugs (bDMARD) in rheumatoid arthritis (RA) patients treated with bDMARDs. PATIENTS AND METHODS: This was a population-based cohort study conducted in five provinces of Canada (Alberta, Manitoba, Ontario, Quebec, and Saskatchewan), and one American database (IBM® MarketScan® Databases). Adult RA patients entered the study after a 3-month initiation period of bDMARDs between 1 January 2007, and 30 March 2014. Concomitant csDMARD exposure was compared to non-csDMARD exposure on the following outcomes: discontinuation of bDMARD therapy, switching of bDMARDs, and percent change in dose of bDMARD compared to initial dose. The effect of the time-varying changes in csDMARD exposure was analyzed using marginal structural models. Dose change was analyzed using linear regression. Results from each participating site were combined using likelihood ratio meta-analysis. RESULTS: The study population comprised 20,221 new users of bDMARDs: adalimumab (7609), etanercept (9809), abatacept (1024), infliximab (1779). Concomitant use of csDMARD therapy was not significantly associated with reduced discontinuation of bDMARD treatment (hazard ratio 0.90, 95% intrinsic confidence interval 0.79 to 1.02) or reduced switching of bDMARDs (hazard ratio 0.95, 95% intrinsic confidence interval 0.80 to 1.11), but was associated with a small increase in bDMARD dose compared to the mean dose over the first three months of treatment (mean percentage change in dose +0.56% mg/day, 95% intrinsic confidence interval +0.14% to +0.97%). CONCLUSION: In this large study of RA patients using bDMARDs in Canada and the United States, we found no clear evidence that patients who received concomitant csDMARD therapy were less likely to discontinue, switch or increase their dose of bDMARD.

Comparison of Pregnancy Outcomes of Patients Treated With Ondansetron vs Alternative Antiemetic Medications in a Multinational, Population-Based Cohort.

Importance: Ondansetron is frequently used to treat nausea and vomiting during pregnancy. Although some studies reported important safety signals, few studies have been sufficiently large to assess rare pregnancy outcomes. Objective: To study the association between ondansetron exposure during pregnancy and the risks of spontaneous abortion, stillbirth, and major congenital malformations. Design, Setting, and Participants: This is a cohort study conducted in 3 countries, with a meta-analysis. Participants included women and girls aged 12 to 55 years who experienced spontaneous abortion, induced abortion, stillbirth, or live birth between April 2002 and March 2016, as recorded in administrative data from 5 Canadian provinces (British Columbia, Alberta, Saskatchewan, Manitoba, and Ontario), the US IBM MarketScan Research Databases, and the UK Clinical Practice Research Datalink. The statistical analysis was completed in October 2020. Exposures: Exposure to ondansetron during pregnancy was compared with exposure to other commonly used antiemetics to minimize confounding by indication. Main Outcomes and Measures: The primary outcome was fetal death, defined as either spontaneous abortion or stillbirth. Secondary outcomes were the 2 components of the primary outcome and major congenital malformations identified during the year after a live birth. Adjusted hazard ratios were estimated using Cox proportional hazards models with time-dependent drug exposures and were adjusted using high-dimensional propensity scores. For major congenital malformations, adjusted odds ratios were estimated from logistic models. Site-level results were pooled using random-effects meta-analysis. Sensitivity analyses considered second-line antiemetic exposure and exposure specifically during 4 to 10 weeks of gestation. Results: Data from 456 963 pregnancies were included in this study of fetal death (249 787 [54.7%] in Canada, 197 913 [43.3%] in the US, and 9263 [2.0%] in the UK; maternal age, ≤24 years, 93 201 patients [20.4%]; 25-29 years, 149 117 patients [32.6%]; 30-34 years, 142 442 patients [31.2%]; and ≥35 years, 72 203 patients [15.8%]). Fetal death occurred in 12 907 (7.9%) of 163 810 pregnancies exposed to ondansetron, and 17 476 (5.7%) of 306 766 pregnancies exposed to other antiemetics. The adjusted hazard ratios were 0.91 (95% CI, 0.67-1.23) for fetal death with time-dependent ondansetron exposure during pregnancy, 0.82 (95% CI, 0.64-1.04) for spontaneous abortion, and 0.97 (95% CI, 0.79-1.20) for stillbirth. For major congenital malformations, the estimated odds ratio was 1.06 (95% CI, 0.91-1.22). Results of sensitivity analyses were generally consistent with those of the primary analyses. Conclusions and Relevance: In this large, multicenter cohort study, there was no association between ondansetron exposure during pregnancy and increased risk of fetal death, spontaneous abortion, stillbirth, or major congenital malformations compared with exposure to other antiemetic drugs.

Comparative Safety of Smoking Cessation Pharmacotherapies During a Government-Sponsored Reimbursement Program.

INTRODUCTION: The British Columbia Ministry of Health launched a Smoking Cessation Program on September 30, 2011, providing financial coverage for smoking cessation pharmacotherapies. Although pharmacotherapies have been shown to have a moderate short-term benefit as a quitting aid, substantial cardiovascular and neuropsychiatric safety concerns have been identified in adverse-reporting databases, leading to prescription label warnings by Health Canada and the U.S. Food and Drug Administration. However, recent studies indicate these warnings may be without merit. This study examined the comparative safety of medications commonly used to aid smoking cessation. AIMS AND METHODS: Population-based retrospective cohort study using B.C. administrative data to assess the relative safety between varenicline, bupropion, and nicotine replacement therapies (NRTs). The primary outcome was a composite of cardiovascular hospitalizations. Secondary outcomes included mortality, a composite of neuropsychiatric hospitalizations, and individual components of the primary outcome. Statistical analysis used propensity score-adjusted log-binomial regression models. A sensitivity analysis excluded patients with a history of cardiovascular disease. RESULTS: The study included 116 442 participants. Compared with NRT, varenicline was associated with a 10% 1-year relative risk decrease of cardiovascular hospitalization (adjusted risk ratio [RR] = 0.90, 95% confidence interval (CI): 0.82 to 1.00), a 20% 1-year relative risk decrease of neuropsychiatric hospitalization (RR: 0.80, CI: 0.7 to 0.89), and a 19% 1-year relative risk decrease of mortality (RR: 0.81, CI: 0.71 to 0.93). We found no significant association between NRT and bupropion for cardiovascular hospitalizations, neuropsychiatric hospitalizations, or mortality. CONCLUSIONS: Compared with NRT, varenicline is associated with fewer serious adverse events and bupropion the same number of serious adverse events. IMPLICATIONS: This study addresses the need for comparative safety evidence in a real-world setting of varenicline and bupropion against an active comparator. Compared with NRT, varenicline was associated with a decreased risk of mortality, serious cardiovascular events, and neuropsychiatric events during the treatment, or shortly after the treatment, in the general population of adults seeking pharmacotherapy to aid smoking cessation. These results provide support for the removal of the varenicline boxed warning for neuropsychiatric events and add substantively to the cardiovascular safety findings of previous observational studies and randomized clinical trials.

Tofacitinib Persistence in Patients with Rheumatoid Arthritis: A Retrospective Cohort Study.

OBJECTIVE: To compare medication persistence of tofacitinib with persistence of injectable biological disease-modifying antirheumatic drugs (bDMARD) in patients with rheumatoid arthritis (RA). METHODS: We performed a retrospective new-user cohort study of patients with RA in the IBM MarketScan Research Databases. New users of tofacitinib or bDMARD were identified between November 2012 and December 2016. Persistence, in number of years, was the time between treatment initiation and the earliest occurrence of discontinuation or switching from the medication prescribed at cohort entry. Persistence of tofacitinib was compared with bDMARD persistence using Cox proportional hazards regression with adjustment for high-dimensional propensity scores. Similar methods were used for an analysis of post first-line therapy in patients who switched to tofacitinib from a bDMARD. RESULTS: New tofacitinib users (n = 1031) were 56 years of age, on average, and 82% were women. New bDMARD users (n = 17,803) were 53 years of age, on average, and 78% were women. New tofacitinib users had shorter medication persistence (median 0.81 yrs) compared to bDMARD patients (1.02 yrs). After adjustment, the HR for discontinuation of tofacitinib compared with bDMARD was 1.14 (95% CI 1.05-1.25). Patients who switched to tofacitinib from a bDMARD had longer persistence than patients who switched to a bDMARD (adjusted HR for discontinuation 0.90, 95% CI 0.83-0.97). CONCLUSION: Further research is warranted to understand the reasons for discontinuation of tofacitinib despite its ease of administration and to understand the observed differences between switchers and new users.

Sodium glucose cotransporter 2 inhibitors and risk of major adverse cardiovascular events: multi-database retrospective cohort study.

OBJECTIVE: To compare the risk of cardiovascular events between sodium glucose cotransporter 2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors among people with type 2 diabetes in a real world context of clinical practice. DESIGN: Multi-database retrospective cohort study using a prevalent new user design with subsequent meta-analysis. SETTING: Canadian Network for Observational Drug Effect Studies (CNODES), with administrative healthcare databases from seven Canadian provinces and the United Kingdom, 2013-18. POPULATION: 209 867 new users of a SGLT2 inhibitor matched to 209 867 users of a DPP-4 inhibitor on time conditional propensity score and followed for a mean of 0.9 years. MAIN OUTCOME MEASURES: The primary outcome was major adverse cardiovascular events (MACE, a composite of myocardial infarction, ischaemic stroke, or cardiovascular death). Secondary outcomes were the individual components of MACE, heart failure, and all cause mortality. Cox proportional hazards models were used to estimate site specific adjusted hazards ratios and 95% confidence intervals, comparing use of SGLT2 inhibitors with use of DPP-4 inhibitors in an as treated approach. Site specific results were pooled using random effects meta-analysis. RESULTS: Compared with DPP-4 inhibitors, SGLT2 inhibitors were associated with decreased risks of MACE (incidence rate per 1000 person years: 11.4 v 16.5; hazard ratio 0.76, 95% confidence interval 0.69 to 0.84), myocardial infarction (5.1 v 6.4; 0.82, 0.70 to 0.96), cardiovascular death (3.9 v 7.7; 0.60, 0.54 to 0.67), heart failure (3.1 v 7.7; 0.43, 0.37 to 0.51), and all cause mortality (8.7 v 17.3; 0.60, 0.54 to 0.67). SGLT2 inhibitors had more modest benefits for ischaemic stroke (2.6 v 3.5; 0.85, 0.72 to 1.01). Similar benefits for MACE were observed with canagliflozin (0.79, 0.66 to 0.94), dapagliflozin (0.73, 0.63 to 0.85), and empagliflozin (0.77, 0.68 to 0.87). CONCLUSIONS: In this large observational study conducted in a real world clinical practice context, the short term use of SGLT2 inhibitors was associated with a decreased risk of cardiovascular events compared with the use of DPP-4 inhibitors. TRIAL REGISTRATION: ClinicalTrials.gov NCT03939624.