title: Comparison of cross-sectional and longitudinal designs in the study of aging of upper extremity performance.
abstract: The purpose of the study was to compare two research designs, namely the cross-sectional design and the longitudinal design, in the context of upper extremity performance and age-related changes. Upper extremity performance of 360 randomly recruited healthy, community-dwelling elderly persons was evaluated with reliable and valid sensori-motor tests. Three years later, survivors (n = 264) were reevaluated with the same tests. In many tests, cross-sectional and longitudinal designs were comparable for estimating the changes in upper extremity performance with age. However, in some tests, the decline with age using a cross-sectional design was underestimated. The upper extremity performance decline observed with the longitudinal design was larger than the decline predicted with the cross-sectional design. The withdrawal and survivor biases related to the longitudinal design and the cohort bias associated with the cross-sectional design may, in part, explain these results.
authors.affiliation: Centre de Recherche en Gérontologie et Gériatrie, Sherbrooke Geriatric University Institute, Québec, Canada. jdesrosi@courrier.usherb.ca
authors.forename: J
authors.initials: J
authors.lastname: Desrosiers
authors.forename: R
authors.initials: R
authors.lastname: Hébert
authors.forename: G
authors.initials: G
authors.lastname: Bravo
authors.forename: A
authors.initials: A
authors.lastname: Rochette
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006225:Hand / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012107:Research Design