Determinants of Between-Person Variation in Shoulder Pain in Individuals With Spinal Cord Injury: A Population-Based Cohort Study.

Abstract

The aim of the study was to evaluate determinants of between-person variation in shoulder pain ("yes"/"no") in individuals with spinal cord injury living in Switzerland. This longitudinal study used data from the Swiss Spinal Cord Injury Cohort community surveys 2012, 2017, and 2022. Logistic regression analyses were used to identify determinants of between-person variability in shoulder pain while controlling for within-person variability. The prevalence of shoulder pain was 34.4% (95% CI = 33.0-35.9) when studying 4393 completed questionnaires. Significant determinants for between-subject variability revealed higher likelihoods for shoulder pain in females as compared with males (odds ratio: 1.57; 95% CI = 1.21-2.05), and when spasticity (1.49; 1.14-1.95), contractures (2.77; 2.21-3.48), and depression (1.39; 1.02-3.48) were present. In addition, shoulder pain presented highest likelihoods in individuals with incomplete tetraplegia (1.81; 1.32-2.48) versus incomplete paraplegia, in individuals over 26 yrs since injury (1.65; 1.15-2.37) versus up to 5 yrs since injury, and in individuals using a manual (2.17; 1.53-3.08) or electrical (2.16; 1.41-3.31) wheelchair versus no aids. There were significant interaction effects for gender with time since injury, contractures, and depression. Determinants of between-subject variability in shoulder pain were female gender, lesion severity, time since injury, specific health conditions, and wheelchair use.