An evaluation of the representativeness of a national spinal cord injury registry: a population-based cohort study

Study design Population-based cohort study for the western part of Quebec. Objectives To determine the impact of declining to participate in a national spinal cord injury (SCI) registry on patient outcomes and continuum of care. Setting Level-1 trauma center specialized in SCI care in Montreal, Canada. Methods This cohort study compared the outcomes of 444 patients who were enrolled in the Rick Hansen SCI registry and 140 patients who refused. Logistic regression analyses were performed to assess the association between voluntary participation and the outcomes, while adjusting for confounding factors. The main outcomes were: attendance to follow-up 6- to 12-month post injury, 1-year mortality, and the occurrence of pressure injury during acute care. Results Declining to be enrolled in the registry was a significant predictor of lower attendance to specialized follow-up (adjusted odds ratio [OR] 0.04, 95% confidence interval [CI] 0.02–0.08). It was also associated with a higher 1-year mortality rate (OR 12.50, CI 4.50–33.30) and higher occurrence of pressure injury (OR 2.56, CI 1.56–4.17). Conclusions This study sheds invaluable insight on individuals that researchers and clinicians are usually blind to in SCI cohort studies. This study suggests that decline to participate in a registry during the care hospitalization may be associated with worsened health, poorer outcomes, and reduced follow-up to specialized care. Declining the enrollment to voluntary registry could represent a potential prognostic factor for future research.