A transitional model of barrier methods compliance with unbalanced loss to follow-up

✍ Scribed by Pai-Lien Chen; Emelita Wong; Rosalie Dominik; Markus J. Steiner

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 115 KB
• Volume: 19
• Category: Article
• ISSN: 0277-6715
• DOI: 10.1002/(sici)1097-0258(20000115)19:1<71::aid-sim292>3.0.co;2-o

✦ Synopsis

Di!erential loss to follow-up can substantially in#uence the evaluation of treatment e!ects on a dichotomous outcome of interest in longitudinal trials. The use of transitional models incorporating loss to follow-up as an additional category of response and the nature of the correlated responses can provide a comprehensive view of a trial with unbalanced loss to follow-up. Under the Markov assumption, transitional models estimate the probability of changing from one outcome to another outcome between follow-up visits. Patterns of the response variable can be described by the estimated transition probabilities. The e!ects of intervention and covariates on the outcome of interest can also be estimated using a conditional likelihood function or a multinomial logit regression. Data from a randomized barrier method study designed to compare the proportion of participants using barrier methods consistently in two counselling groups are used to illustrate the proposed model.