Relationships Among Perceived Functional Capacity, Self-Efficacy, and Disability After Dysvascular Amputation

Background Prosthesis rehabilitation after dysvascular transtibial amputation (TTA) is focused on optimizing functional capacity with limited emphasis on promoting health self-efficacy. Self-efficacy interventions decrease disability for people living with chronic disease, but the influence of self-efficacy on disability is unknown for people with dysvascular TTA. Objectives To identify if self-efficacy mediates the relationship between self-reported functional capacity and disability after dysvascular TTA. Design Cross-sectional, secondary data analysis. Setting Outpatient rehabilitation facilities. Participants Thirty-eight men (63.6 ± 9.1 years old) with dysvascular TTA. Methods Participants had been living with an amputation for less than 6 months and using walking as their primary form of locomotion using a prosthesis. The independent variable, functional capacity, was measured using the Prosthesis Evaluation Questionnaire–Mobility Scale (PEQ-MS). The proposed mediator, self-efficacy, was measured with the Self-Efficacy of Managing Chronic Disease questionnaire (SEMCD). Main Outcome Measure Disability was measured using the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) questionnaire. Results The relationship between self-reported functional capacity and disability is partially mediated by self-efficacy. Relationships between WHODAS 2.0 and PEQ-MS (r = –0.61), WHODAS 2.0 and SEMCD (r = –0.51), and PEQ-MS and SEMCD (r = 0.44) were significant (P < .01). Controlling for SEMCD (P = .04), the relationship between PEQ-MS and WHODAS 2.0 remained significant (P < .01). Statistically significant mediation was determined by a bootstrap method for the product of coefficients (95% confidence interval: –2.23, –7.39). Conclusions This study provides initial evidence that the relationship between self-reported functional capacity and disability is partially mediated by self-efficacy after dysvascular TTA. The longitudinal effect of self-efficacy should be further examined to identify causal pathways of disability after dysvascular amputation. Furthermore, additional factors contributing to the relationship between self-reported functional capacity and disability need to be identified. Level of Evidence III