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

Abstract

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.

Figure 1

Proposed relationships among Self-Reported Physical Function, Self-Reported Disability, and Chronic Disease Management Self-Efficacy