Subgroup analysis of large trials can guide further research: a case study of vitamin E and pneumonia.

ABSTRACT:

Background

Biology is complex and the effects of many interventions may vary between population groups. Subgroup analysis can give estimates for specific populations, but trials are usually too small for such analyses.

Purpose

To test whether the effect of vitamin E on pneumonia risk is uniform over subgroups defined by smoking and exercise.

Methods

The Alpha-Tocopherol Beta-Carotene Cancer Prevention Study examined the effects of vitamin E (50 mg per day) and β-carotene (20 mg per day) on lung cancer in 29,133 male smokers aged 50-69 years using a 2 × 2 factorial design. The trial was conducted among the general community in Finland during 1985-1993; the intervention lasted for 6.0 years (median). In the present study, we tested the uniformity of vitamin E effect on

SUBMITTER: Hemila H 

PROVIDER: S-EPMC3046185 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature