Development and reliability of the lifetime interview on smoking trajectories.

INTRODUCTION: Assessments of lifetime smoking history are useful in many types of research including surveillance, epidemiology, prevention, intervention, and studies of genetic phenotypes and heritability. Because prospective assessment is impractical for most research, our objective was to develop a reliable retrospective measure of lifetime smoking history. This paper presents descriptive and test-retest reliability data on smoking history variables assessed using the Lifetime Interview on Smoking Trajectories (LIST).
METHODS: Data were collected on a birth cohort sample of 1,625 men and women (ages 34-44) from the Collaborative Perinatal Project. A subsample of 344 was invited to participate in a retest interview 4-8 weeks later and 220 participated. Indices of test-retest reliability were evaluated for smoking history variables, including: (a) early smoking experiences; (b) age at various smoking milestones, such as first puff, and progression to weekly and daily smoking; (c) smoking rate and time to first cigarette within initial, current, most recent, and heaviest phases; and (d) prolonged nonsmoking phases.
RESULTS: Responses to whether each of 5 major smoking milestones occurred were all highly reliable (κ = .78-.92), and of the 20 phase-specific variables assessed, more than half were reported at the highest level of reliability. None of the variables demonstrated low reliability.
CONCLUSIONS: Although retrospective reports have unavoidable limitations, our findings indicate that the LIST is a reliable instrument for assessing detailed retrospective smoking history data and can be used to add to the knowledge base of how patterns of use relate to a variety of outcomes of interest.