title: Life-table methods for detecting age-risk factor interactions in long-term follow-up studies.
abstract: Methodological investigation has suggested that age-risk factor interactions should be more evident in age of experience life tables than in follow-up time tables due to the mixing of ages of experience over follow-up time in groups defined by age at initial examination. To illustrate the two approaches, age modification of the effect of total cholesterol on ischemic heart disease mortality in two long-term follow-up studies was investigated. Follow-up time life table analysis of 116 deaths over 20 years in one study was more consistent with a uniform relative risk due to cholesterol, while age of experience life table analysis was more consistent with a monotonic negative age interaction. In a second follow-up study (160 deaths over 24 years), there was no evidence of a monotonic negative age-cholesterol interaction by either method. It was concluded that age-specific life table analysis should be used when age-risk factor interactions are considered, but that both approaches yield almost identical results in absence of age interaction. The identification of the more appropriate life-table analysis should be ultimately guided by the nature of the age or time phenomena of scientific interest.
mesh_terms: D000206:Actuarial Analysis; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002784:Cholesterol / Q000097:blood; D003327:Coronary Disease / Q000401:mortality; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D011446:Prospective Studies; D012306:Risk; D013223:Statistics as Topic
chemical_list: D002784:Cholesterol