Background/Purpose: Self-efficacy is a key determinant of health behaviors and the target mechanism of self-management programs for patients with chronic diseases. The Self-Efficacy for Managing Chronic Disease (SEMCD) scale, a brief self-report instrument, has been widely used to measure self-efficacy in chronic disease populations and is validated in English for use in people with systemic sclerosis (SSc). However, it is essential that translations of measures be examined for psychometric equivalence across populations, and no research has yet ascertained that SEMCD scores are comparable across languages. The present study examined the cross-language measurement equivalence of the SEMCD in a sample of English- or French-speaking adults with SSc.

Methods: Adults with SSc (N = 2159; 87.4% female; 57.3% limited SSc; 68.3% English-speaking) from 46 centers were enrolled in the Scleroderma Patient-Centered Intervention Network (SPIN) Cohort. All participants were classified as having SSc according to the 2013 ACR/EULAR classification criteria. The SEMCD scale includes 6 items and higher scores indicate higher levels of self-efficacy. Confirmatory factor analysis (CFA) was used to confirm the single-factor structure of the SEMCD scale. Cronbach’s coefficient alpha and McDonald’s omega were used to evaluate internal consistency reliability. Multiple group confirmatory factor analysis (MGCFA) was used to determine whether the single-factor structure was supported in both languages. The Multiple-Indicator Multiple-Cause (MIMIC) model was used to examine differential item functioning (DIF).

Results: The mean total score on the SEMCD was 6.45 (SD = 2.26, range = 1-10). The SEMCD demonstrated good internal consistency reliability (α = .93, ω = .93). CFA indicated that a one-factor model fit well based on 2 of the 3 tested indices of model fit (Comparative Fit Index [CFI] = .96, Standardized Root Mean Residual [SRMR] = .03). The Root Mean Square Error of Approximation (RMSEA) indicated less than acceptable model fit (RMSEA = .14). Standardized factor loadings for all items were large and statistically significant (all ps < .001; range .755 to .879). Results from the MGCFA supported the metric invariance model as the best fit for the data (Δχ² [10, N = 2159] = 13.32, p = .206), suggesting that the factor loadings are invariant across English and French language versions. The overall MIMIC model fit well and indicated that the SEMCD items demonstrate cross-language metric equivalence (CFI = .96, SRMR = .03, RMSEA = .12), although a statistically significant but small-magnitude DIF was found for one SEMCD item across language (β = .03, p < .05).

Conclusion: Findings support the use of the SEMCD as a reliable and valid single-factor measure of self-efficacy in SSc. SEMCD scores from English- and French-speaking individuals with SSc can be compared or combined for analysis. Future studies should examine the metric equivalence of the SEMCD across other linguistic and sociodemographic groups (e.g., race/ethnicity, sex).

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/a-psychometric-analysis-of-the-self-efficacy-for-managing-chronic-disease-scale-in-systemic-sclerosis-a-scleroderma-patient-centered-intervention-network-cohort-study/