Reliability, validity and factor structure of the Appraisal of Self‐Care Agency Scale – Revised (ASAS‐R)

Abstract Rationale, aims and objectives Self‐care agency is a fundamental concept in nursing and health care research. Having self‐care agency enhances an individual's health‐promoting behaviours and/or specific capabilities for chronic disease self‐management. The purpose of this study was to continue the development and psychometric testing of the Appraisal of Self‐Care Agency – Revised (ASAS‐R). Methods A cross‐sectional methodological design was used to examine the reliability, validity and factor structure of the ASAS‐R among individuals from the general population. The sample consisted of 629 adults who were randomly selected to conduct an exploratory factor analysis (EFA; n = 240) and a confirmatory factor analysis (CFA; n = 389) of the scale. A demographic questionnaire, the ASAS‐R and the Health‐Promoting Lifestyle Profile (HPLP‐II) were the measures used to collect the data. Results The final 15‐item three‐factor ASAS‐R had an overall Cronbach's alpha (α) of 0.89. The three factors extracted, rotated and scored in this study were labelled: having power for self‐care, developing power for self‐care and lacking power for self‐care. All inter‐items and item‐to‐total correlations met recommended criteria of r = 0.30 to r = 0.70, except for one of the items that had an item‐to‐total correlation of 0.71, slightly exceeding the maximum recommended item‐to‐total correlation. The three factors had Cronbach's alphas of 0.86, 0.83 and 0.79, respectively. The three factors together explained 61.7% of the scale items variance. Each item of the scale had a strong factor loading ranging from 0.52 to 0.81. All measures of model fit exceeded the recommended criteria, indicating that the 15‐item ASAS‐R had a very good fit (χ 2 /d.f. = 1.97, GFI = 0.94, AGFI = 0.92, CFI = 0.96, TLI = 0.95, RMSEA = 0.05, RMR = 0.05 and the PCLOSE = 0.48). Conclusions The 15‐item three‐factor ASAS‐R is a short, reliable and valid instrument to measure self‐care agency among individuals from the general population, but further psychometric evaluation is needed among individuals with chronic diseases, especially those with diabetes mellitus.