Trial
PROSPER: pravastatin in older adults
Research Observatory
Evidence Update
Current evidence
PROSPER compared pravastatin 40 mg daily with placebo in 5,804 adults aged 70-82 with previous vascular disease or risk factors, followed for an average of 3.2 years.The main combined outcome occurred in 408 of 2,891 people assigned pravastatin and 473 of 2,913 assigned placebo. The stroke-only estimate remained uncertain. The mixed population limits comparison with healthy older adults. The abstract alone does not provide a complete assessment of harms or separate results for everyone aged 80 or older.This study-specific finding does not establish general clinical efficacy or longer life.
What changed
Study findings and context:PROSPER found fewer primary composite vascular events with pravastatin in a population aged 70-82 that mixed people with prior vascular disease and those with risk factors; that overall estimate is not an isolated primary-prevention effect.
What did not change
The overall result does not isolate the effect in people without previous vascular disease. It does not establish dementia prevention or longer life.
Why it matters
Helps readers see why a result from a mixed prevention population cannot be presented as an answer for all healthy older adults.
Main limitation
Mixed primary/secondary prevention; do not transfer the overall HR to healthy older adults. No source-qualified separate >=80 efficacy or dementia-prevention estimate. Shorter follow-up and selected trial participants limit late benefit and competing-risk interpretation. Only the official indexed abstract was requalified; no new appraisal of every component or harm. Access qualification: Official indexed author abstract only; full methods and supplements unreviewed.
Next proof
Use the linked original reports to check the findings. Full methods, tables and supplements were not reviewed in this evidence package. Broader clinical questions require separate evidence review.
Study findings and exact evidence
Pravastatin 40 mg daily (PROSPER regimen)
Pravastatin results in a mixed older population
ACCEPT_AS_CONTEXT
What was tested? Pravastatin 40 mg daily was compared with placebo for a combined outcome of coronary death, nonfatal heart attack or stroke.
Who participated? The study included 5,804 adults aged 70-82. Some had previous vascular disease; others had risk factors. Average follow-up was 3.2 years.
Findings The main combined outcome occurred in 408 of 2,891 people assigned pravastatin and 473 of 2,913 assigned placebo. The stroke-only estimate remained uncertain.
What was not demonstrated? The overall result does not isolate the effect in people without previous vascular disease. It does not establish dementia prevention or longer life.
Harms and limitations The mixed population limits comparison with healthy older adults. The abstract alone does not provide a complete assessment of harms or separate results for everyone aged 80 or older.
PROSPER found fewer primary composite vascular events with pravastatin in a population aged 70-82 that mixed people with prior vascular disease and those with risk factors; that overall estimate is not an isolated primary-prevention effect.
Exact accepted support, hierarchy and limitations
exact accepted proposition
PROSPER found fewer primary composite vascular events with pravastatin in a population aged 70-82 that mixed people with prior vascular disease and those with risk factors; that overall estimate is not an isolated primary-prevention effect.
exact numeric support
[{"confidence_interval": [0.74, 0.97], "confidence_level": 0.95, "denominator_comparator": 2913, "denominator_intervention": 2891, "effect_scale": "hazard_ratio", "endpoint": "Primary vascular composite", "estimate": 0.85, "events_comparator": 473, "events_intervention": 408, "p_value": 0.014}, {"confidence_interval": [0.81, 1.31], "confidence_level": 0.95, "denominator_comparator": 2913, "denominator_intervention": 2891, "effect_scale": "hazard_ratio", "endpoint": "Stroke component", "estimate": 1.03, "p_value": 0.8}]exact original limitations
Mixed primary/secondary prevention; do not transfer the overall HR to healthy older adults. No source-qualified separate >=80 efficacy or dementia-prevention estimate. Shorter follow-up and selected trial participants limit late benefit and competing-risk interpretation. Only the official indexed abstract was requalified; no new appraisal of every component or harm. Access qualification: Official indexed author abstract only; full methods and supplements unreviewed.
exposure and comparator
Pravastatin 40 mg daily Comparator: Placebo; randomized trial
follow up
Mean 3.2 years
interpretation
Hazard ratios compare event hazards during follow-up; they are not individual probabilities or cumulative risk differences. Confidence intervals express uncertainty. Person-years add participants’ follow-up time.
outcome hierarchy
Primary: coronary death/nonfatal MI/fatal or nonfatal stroke. Stroke, cognition, disability and cancer findings require separate interpretation.
population
5804 adults aged 70-82, with vascular disease or risk factors; 2804 men and 3000 women. Species: Homo sapiens.
Summary
PROSPER compared pravastatin 40 mg daily with placebo in 5,804 adults aged 70-82 with previous vascular disease or risk factors, followed for an average of 3.2 years.The main combined outcome occurred in 408 of 2,891 people assigned pravastatin and 473 of 2,913 assigned placebo. The stroke-only estimate remained uncertain. The mixed population limits comparison with healthy older adults. The abstract alone does not provide a complete assessment of harms or separate results for everyone aged 80 or older.This study-specific finding does not establish general clinical efficacy or longer life.
Intelligence Take
Helps readers see why a result from a mixed prevention population cannot be presented as an answer for all healthy older adults.
Limitations
Mixed primary/secondary prevention; do not transfer the overall HR to healthy older adults. No source-qualified separate >=80 efficacy or dementia-prevention estimate. Shorter follow-up and selected trial participants limit late benefit and competing-risk interpretation. Only the official indexed abstract was requalified; no new appraisal of every component or harm. Access qualification: Official indexed author abstract only; full methods and supplements unreviewed.