ArticleCMAJ open
Postmarket safety of drugs approved by Health Canada on the basis of clinical and surrogate outcomes: a cohort study.
Article in CMAJ open. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
3 citing papers in PubMed.
- Weight normativity in action: Semaglutide and obesity.Canadian family physician Medecin de famille canadien · 2025Article
- Unwarranted claims of drug efficacy in pharmaceutical sales visits: are drugs approved on the basis of surrogate outcomes promoted appropriately?British journal of clinical pharmacology · 2017Article
- Drug approval status and recommendations for listing on public formularies: a Canadian cohort analysis.BMJ open · 2017Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundHealth Canada approves drugs on the basis of evidence from clinical trials using clinical or surrogate outcomes. This study compares the postmarket safety of these 2 groups of drugs.
methodsInformation about whether clinical or surrogate outcomes were used and the date of market approval were obtained from Health Canada's Summary Basis of Decision documents issued from Jan. 1, 2005, to Dec. 31, 2014. Safety warnings and the dates they were issued were identified through advisories on the MedEffect Canada website. Kaplan-Meier survival curves were calculated to determine the likelihood that drugs in the clinical and surrogate outcome groups would receive a serious safety warning. The time from market authorization to first serious safety warning was compared for the 2 groups of drugs.
resultsA total of 124 drugs were approved by Health Canada using clinical outcomes and 114 using surrogate outcomes. Kaplan-Meier curves did not differ between the 2 groups (p < 0.9). The median time from market authorization to first serious safety warning was 722 days in the clinical outcome group and 818 days in the surrogate outcome group (difference 96 days, 95% confidence interval -295 to 425).
interpretationWe found no statistically significant difference in postmarket safety between drugs approved using clinical outcomes and those approved using surrogate outcomes. Because drugs in the surrogate outcome group are approved before their benefit:harm ratio is fully established, these drugs should be used with caution until their clinical benefits are better understood.
Identifiers
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Registered trials
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