Understanding age effects associated with changes in secondary health conditions in a Canadian spinal cord injury cohort

Study design: Longitudinal cohort. Objectives: To determine whether changes in secondary health conditions (SHC) associated with spinal cord injury (SCI) were effectively modeled from a longitudinal or cross-sectional perspective, and whether the changes in SHCs were attributable to age or years post-injury (YPI). Setting: Toronto Rehabilitation Institute, Lyndhurst Centre. Methods: Telephone survey methods were used to collect data on (1) demographics, (2) impairment, (3) health status, and (4) self-reported SHCs at two time intervals (1995–1997; 2003–2004) from 344 adults with SCI. Generalized estimating equations were applied to model the longitudinal and cross-sectional effects. Results: Health status decreased over time ( P