Construct validity and reliability of the participation scale (P-scale) in individuals with spinal cord injury

Abstract

Objectives To investigate the reliability and the construct validity of the Participation Scale (P-scale) in adults with Spinal Cord Injury (SCI). Design A cross-sectional study. Setting : SARAH Network of Rehabilitation Hospitals, Brazil. Participants : One hundred individuals with SCI. Interventions : Not applicable. Outcome Measures : Sociodemographic and clinical characteristics were investigated. To assess reliability the P-scale was applied twice with a one-week interval. To assess construct validity the Functional Independence Measure, the Beck Depression Inventory, and the Accessibility Perception Questionnaire were administered. Results The mean age of the participants was 38.9 ± 12.80 years. The majority were male (70%) and had traumatic injuries (74%). The P-scale showed significant correlations with the Functional Independence Measure motor domain (rs = −0.280) and cognitive domain (rs = −0.520); with the Beck Depression Inventory score (rs = 0.610); with the Accessibility Perception Questionnaire displacement domain (rs = −0.620) and psycho-affective domain (rs = 0.530). Mean scores obtained on the P-scale differed significantly between the groups with and without depressive symptoms (P = 0.001), neuropathic pain (P = 0.033), and functional dependence (P = 0.001). There was no difference between the paraplegic and quadriplegic groups. The P-scale had adequate internal consistency (Cronbach’s alpha = 0.873), excellent test-retest reliability (ICC2,1 = 0.992; 95% CI = 0.987–0.994), and in the Bland–Altman plot analysis, only six values fell outside the limits of agreement. Conclusion Our results support the use of the P-scale to assess the participation of individuals with SCI in research and clinical practice.