title: Methodological issues in conducting and analyzing longitudinal observational studies in rheumatoid arthritis.
abstract: This article discusses 5 methodological issues that arise in the course of conducting longitudinal observational studies: generalizability, missing data, repeated measures on the same individual, measures taken at varying time points from symptom onset, and assessing the effect of treatment. Methods discussed include general estimating equations and propensity scores. The points are illustrated by examples from the Norfolk Arthritis Register dataset.
authors.affiliation: ARC Epidemiology Unit, School of Epidemiology and Health Sciences, The University of Manchester, Manchester, United Kingdom. deborah.Symmons@man.ac.uk
authors.forename: Deborah P M
authors.initials: DP
authors.lastname: Symmons
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000453:epidemiology* / Q000628:therapy; D003625:Data Collection / Q000379:methods; D015340:Epidemiologic Research Design; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008722:Methods; D008875:Middle Aged; D016896:Treatment Outcome