Table 19Key Question 3 – therapy duration: Clopidogrel vs. placebo: 28-days vs. 12 months (CREDO)

Domains pertaining to strength of evidenceMagnitude of effectStrength of evidence
Number of studies; number of subjectsRisk of bias (design/quality)ConsistencyDirectnessPrecisionRR (95% confidence interval)High, moderate, low, insufficient
All-cause mortality
1/N=2116Low (RCT/Good)ConsistentIndirectImprecise0.76 (0.58 to 1.00)aModerate
Cardiovascular mortality
1/N=2116Low (RCT/Good)NRInsufficient
1/N=2116Low (RCT/Good)ConsistentIndirectImprecise1.01 (0.86 to 1.20)aLow
Major bleeding
1/N=2116Low (RCT/Good)ConsistentIndirectImprecise1.32 (0.98 to 1.78)aModerate
Withdrawal due to adverse events
1/N=2116Low (RCT/Good)NRInsufficient

Calculated by OR EPC using StatsDirect.

From: Appendix F, Strength of evidence

Cover of Drug Class Review: Newer Antiplatelet Agents
Drug Class Review: Newer Antiplatelet Agents: Final Update 2 Report [Internet].
Ketchum K, Peterson K, Thakurta S, et al.
Portland (OR): Oregon Health & Science University; 2011 Jun.
Copyright © 2011 by Oregon Health & Science University.

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