Pravastatin for Primary Prevention in Older Adults: Restricted Mean Survival Time Analysis.

Abstract

OBJECTIVES:

To use restricted mean survival time, which summarizes treatment effects in terms of event-free time over a fixed time period, to evaluate the benefit of pravastatin therapy for primary prevention of cardiovascular disease in older adults.

DESIGN:

Secondary analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial-Lipid-Lowering Trial (ALLHAT-LLT).

SETTING:

Ambulatory setting.

PARTICIPANTS:

Individuals aged 65 and older (mean aged 71, 49% female) free of cardiovascular disease (N=2,867).

INTERVENTION:

Pravastatin 40 mg/d (n=1,467) versus usual care (n=1,400).

MEASUREMENTS:

We estimated the difference in RMST for total and coronary heart disease (CHD)-free survival between the pravastatin and usual care groups over the 6-year trial period and used parametric survival models to estimate RMST differences projected over 10 years.

RESULTS:

Over 6 years, individuals treated with pravastatin lived (RMST 2,008.1 days), on average, 33.7 fewer days than those receiving usual care (RMST 2,041.8 days) (difference -33.7 days, 95% confidence interval (CI)=-67.0 to -0.5 days, p=.047). Pravastatin-treated individuals lived RMST 2,088.1 days), on average, 18.7 more days free of CHD over 6 years than those receiving usual care (RMST 2,069.4 days), but this difference was not statistically significant (difference 18.7 days, 95% CI=-10.4-47.8 days, p=.21). The 10-year projection showed that pravastatin-treated individuals would live 108.1 fewer days (95% CI=-204.5 to -14.1, p=.03) than those receiving usual care, although treated individuals would gain 77.9 days (95% CI=3.8-159.6, p=.046) of CHD-free survival.

CONCLUSION:

RMST provides an intuitive and explicit way to express the effect of pravastatin therapy on CHD-free and overall survival in older adults free of cardiovascular disease. This measure allows a more personalized interpretation than hazard ratios of the benefits and risks of a medical intervention for decision-making.

• Authors: Ariela R Orkaby, Michael W Rich, Ryan Sun, Eliah Lux, Lee-Jen Wei, Dae Hyun Kim
• Journal: Journal of the American Geriatrics Society (J Am Geriatr Soc) Vol. 66 Issue 10 Pg. 1987-1991 (10 2018) ISSN: 1532-5415 [Electronic] United States
• PMID: 30251369 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © 2018, Copyright the Author Journal compilation © 2018, The American Geriatrics Society.

Chemical References

• Anticholesteremic Agents
• Pravastatin

Topics

• Aged
• Aged, 80 and over
• Anticholesteremic Agents (administration & dosage)
• Coronary Disease (mortality, prevention & control)
• Female
• Humans
• Male
• Middle Aged
• Pravastatin (administration & dosage)
• Primary Prevention (methods, statistics & numerical data)
• Proportional Hazards Models
• Survival Rate
• Time Factors
• Treatment Outcome