Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 53, Issue 5 B362-B368, Copyright © 1998 by The Gerontological Society of America
Comparison of cross-sectional and longitudinal designs in the study of aging of upper extremity performance
J Desrosiers, R Hebert, G Bravo and A Rochette
Centre de Recherche en Gerontologie et Geriatrie, Sherbrooke Geriatric University Institute, Quebec, Canada. jdesrosi@courrier.usherb.ca
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.
