The objective of this paper is to systematically review the literature on drugdrug interactions with warfarin, with a focus on patient-important clinical outcomes.Methods: MEDLINE, EMBASE and the International Pharmaceutical Abstract (IPA) databases were searched from January 2004 to August 2019. We included studies describing drug-drug interactions between warfarin and other drugs. Screening and data extraction were conducted independently and in duplicate. We synthesized pooled odds ratios (OR) with 95% confidence intervals (CIs), comparing warfarin plus another medication to warfarin alone. We assessed the risk of bias at the study level and evaluated the overall certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.Results: Of 42 013 citations identified, a total of 72 studies reporting on 3 735 775 patients were considered eligible, including 11 randomized clinical trials and 61 observational studies. Increased risk of clinically relevant bleeding when added to warfarin therapy was observed for antiplatelet (AP) regimens (OR = 1.74; 95% CI 1.56-1.94),

Background Cost-related nonadherence to medications (CRNA) is common in many countries and thought to be associated with adverse outcomes. The characteristics of CRNA in Canada, with its patchwork coverage of increasingly expensive medications, are unclear. Objectives Our objective in this systematic review was to summarize the literature evaluating CRNA in Canada in three domains: prevalence, predictors, and effect on clinical outcomes. Methods We searched MEDLINE, Embase, Google Scholar, and the Cochrane Library from 1992 to December 2019 using search terms covering medication adherence, costs, and Canada. Eligible studies, without restriction on design, had to have original data on at least one of the three domains specifically for Canadian participants. Articles were identified and reviewed in duplicate. Risk of bias was assessed using design-specific tools. Results Twenty-six studies of varying quality (n = 483,065 Canadians) were eligible for inclusion. Sixteen studies reported on the overall prevalence of CRNA, with population-based estimates ranging from 5.1 to 10.2%. Factors predicting CRNA included high out-of-pocket spending, low income or financial flexibility, lack of drug insurance, younger age, and poorer health. A single randomized trial of free essential medications with free delivery in Ontario improved adherence but did not find any change in clinical outcomes at 1 year. Conclusion CRNA affects many Canadians. The estimated percentage depends on the sampling frame, the main predictors tend to be financial, and its association with clinical outcomes in Canada remains unproven.

Background Cost-related nonadherence to medications (CRNA) is common in many countries and thought to be associated with adverse outcomes. The characteristics of CRNA in Canada, with its patchwork coverage of increasingly expensive medications, is unclear. Objectives Our objective in this systematic review was to summarize the literature evaluating CRNA in Canada in three domains: prevalence, predictors, and effect on clinical outcomes.Methods We searched MEDLINE, Embase, Google Scholar, and the Cochrane Library from 1992 to December 2019 using search terms covering medication adherence, costs, and Canada. Eligible studies, without restriction on design, had to have original data on at least one of the three domains specifically for Canadian participants. Articles were identified and reviewed in duplicate. Risk of bias was assessed using design-specific tools.Results: Twenty-six studies of varying quality (n=483,065 Canadians) were eligible for inclusion. Sixteen studies reported on the overall prevalence of CRNA, with population-based estimates ranging from 5.1% to 10.2%. Factors predicting CRNA included high out of pocket spending, low income or financial flexibility, lack of drug insurance, younger age, and poorer health. A single randomized trial of free essential medications with free delivery in Ontario improved adherence but did not find any change in clinical outcomes at one year. Conclusion: CRNA affects many Canadians. The estimated percentage depends on the sampling frame, the main predictors tend to be financial, and its association with clinical outcomes in Canada remains unproven.

Aims To identify and evaluate clinical pharmacology (CP) online curricular (e‐Learning) resources that are internationally available for medical students. Methods Literature searches of Medline, EMBASE and ERIC databases and an online survey of faculty members of international English language medical schools, were used to identify CP e‐Learning resources. Resources that were accessible online in English and aimed to improve the quality of prescribing specific medications were then evaluated using a summary percentage score for comprehensiveness, usability and quality, and for content suitability. Results Our literature searches and survey of 252 faculty (40.7% response rate) in 219 medical schools identified 22 and 59 resources respectively. After screening and removing duplicates, 8 eligible resources remained for evaluation. Mean total score was 53% (standard deviation = 13). The Australian National Prescribing Curriculum, ranked highest with a score of 77%, based primarily on very good ratings for usability, quality and suitable content. Conclusion Using a novel method and evaluation metric to identify, classify, and rate English language CP e‐Learning resources, the National Prescribing Curriculum was the highest ranked open access resource. Future work is required to implement and evaluate its effectiveness on prescribing competence.