title: Comparing the quality-adjusted life-year output of two treatment arms in a randomized trial.
abstract: The quality-adjusted life year (QALY) is an outcome measure with two dimensions: wellness and time. It is difficult to compare the QALY output of two groups when subjects are observed for varying time periods, because both elements of the two-dimensional outcome measure vary in all subjects. This paper evaluates the strengths and weaknesses of five approaches for making these comparisons. These approaches are: a subject-based approach, the elimination of time, calculation of the mean of available data, use of quality-adjusted survival analysis, and calculation of a maximum likelihood estimation. It is concluded that the maximum likelihood estimation offers significant advantages over the other methods.
authors.affiliation: University of California, San Diego Health Outcomes Assessment Program, La Jolla, USA.
authors.forename: T G
authors.initials: TG
authors.lastname: Ganiats
authors.forename: C J
authors.initials: CJ
authors.lastname: Miller
authors.forename: R M
authors.initials: RM
authors.lastname: Kaplan
mesh_terms: D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D017063:Outcome Assessment, Health Care; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D016019:Survival Analysis; D013997:Time Factors