THE STE-JUSTINE ADOLESCENT IDIOPATHIC SCOLIOSIS COHORT STUDY .1. DESCRIPTION OF THE STUDY

objectives. This study determined the impact of adolescent idiopathic scoliosis (AIS) on health and well being in adulthood by comparing AIS subjects, more than 10 years after referral, to non-AIS subjects acco rding to perceived health status, physical activity, fitness, reproduc tive health, respiratory condition, and back and neck pain. This paper describes the cohort, the design of the study, and response rates. St udy Design. The study was designed as a comparative retrospective coho rt study. A total of 2,092 patients referred for AIS to Ste-Justine Ho spital, Montreal, Quebec, between 1960 and 1979 were identified. A pop ulation-based control group was selected in 1989-90 by randomly teleph oning persons in Quebec. The control group was approximately frequency -matched to the AIS cohort according to age group and broad geographic region of current residence. Methods. Patients with adolescent idiopa thic scoliosis were traced, and a self-administered questionnaire was sent by post in 1989 to subjects whose addresses were found. Identical questionnaires were sent to subjects in the control group. Results. S eventy-one percent of the cohort (1,476 subjects) returned questionnai res in 1989. Subjects who did not respond to the questionnaires were s imilar to those who did complete the questionnaires on a number of key factors, except that lower response rates were observed for subjects with scoliotic curves under 20-degrees. The control group consisted of 1,755 subjects (55% response rate). It was similar to the general Que bec population and to the AIS cohort pn a number of important sociodem ographic factors. Conclusion. Comparisons on health outcomes between t he two study groups should not be affected by differential patterns of selection or response.