High tierMeta Analysis Of RctsCitation verified
Efficacy and safety of LDL-lowering therapy among men and women: meta-analysis of individual data from 174,000 participants in 27 randomised trials
Cholesterol Treatment Trialists' (CTT) Collaboration, Jordan Fulcher, Rachel O'Connell, Anthony Keech, Colin Baigent - The Lancet, 2015
The individual-participant meta-analysis that directly answers "do statins work in women?" Per 1.0 mmol/L of LDL lowering, statins reduced major vascular events to a similar proportional extent in women and men, and reduced all-cause mortality in both sexes - rebutting the recurring claim that the evidence base does not support treating women.
Key findings
- Major vascular events per 1.0 mmol/L LDL reduction: women RR 0.84 (99% CI 0.78-0.91), men RR 0.78 (99% CI 0.75-0.81); no significant heterogeneity by sex (p=0.33).
- All-cause mortality: women RR 0.91 (99% CI 0.84-0.99), men RR 0.90 (99% CI 0.86-0.95).
- Proportional benefit similar across sexes.
Effect measures
- Other: Major vascular events RR 0.84 (women) per 1.0 mmol/L LDL reduction99% CI 0.78-0.91
- Other: All-cause mortality RR 0.91 (women) / 0.90 (men)99% CI 0.84-0.99 (women)
Why this evidence tier (High)
- Risk of bias:
- Individual-participant-data meta-analysis of randomized trials by an established collaboration.
- Precision:
- Very large (174,149); precise, with tight intervals and prespecified sex analysis.
- Directness:
- Directly tests effect modification by sex on hard endpoints.
- Consistency:
- No significant heterogeneity by sex; concordant with the broader CTT evidence.
- Funding / COI:
- Academic/government funded (MRC, BHF, NHMRC, EU Biomed); the underlying trials include industry-sponsored studies.
High certainty that statin benefit (events and mortality) extends to women as it does to men.
- Population:
- Individual-participant data on 174,149 participants in 27 randomised statin/LDL-lowering trials, of whom 46,675 (27%) were women; primary and secondary prevention.
- Conflicts of interest:
- Academically led and publicly/charitably funded; the pooled trials include industry-sponsored studies. Applied evenly with the other CTT reports.
- Funding:
- UK Medical Research Council; British Heart Foundation; Australian NHMRC; European Community Biomed Program.
Limitations
- Pools heterogeneous trials and populations; reports proportional (relative) effects per unit LDL.
- Underlying trials include industry-sponsored studies.