Measuring the self‑control competency of patients with chronic obstructive pulmonary disease: instrument development and validation

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide, and its effective management requires sufficient self‑control competency among patients. Deficits in this competency may contribute to poorer health outcomes, impaired psychological well‑being, and reduced quality of life. However, standardized instruments for the systematic assessment of disease‑specific self‑control competency in patients with COPD remain lacking. This study aimed to develop and validate a COPD‑specific Self‑Control Competency Scale. This methodological study was conducted from January to October 2024 in Suzhou, China. The study comprised two phases. In Phase 1, guided by Social Cognitive Theory, an initial item pool was generated through a literature review, qualitative research, Delphi expert consultation, and a pilot survey. This process yielded a preliminary 23‑item scale spanning four domains. In Phase 2, item analysis and exploratory factor analysis (EFA) were conducted in Sample 1 ( n = 205), and confirmatory factor analysis (CFA) was conducted in an independent Sample 2 ( n = 216). Additional psychometric properties were evaluated using content validity, known‑groups validity, internal consistency, test–retest reliability, and split‑half reliability. The final 19‑item scale comprised four dimensions: cognitive control, emotional control, behavioral control, and environmental control. After three rounds of expert consultation, the scale demonstrated acceptable content validity (I‑CVI = 0.857 to 1.000; overall S‑CVI/UA = 0.913; overall S‑CVI/Ave = 0.988). Exploratory factor analysis supported a four‑factor structure that explained 71.726% of the total variance. Confirmatory factor analysis indicated good model fit (χ 2 / df = 1.692, RMSEA = 0.057, SRMR = 0.046, TLI = 0.966, NFI = 0.932, IFI = 0.971, CFI = 0.971). The scale demonstrated good internal consistency (Cronbach’s α = 0.930), 2‑week test–retest absolute agreement (total‑scale ICC(2, 1) = 0.951, 95% CI = 0.881–0.980), and split‑half reliability (0.963). A theoretically grounded scale for assessing self‑control competency in patients with COPD was developed and underwent initial psychometric validation in this study. This scale may provide preliminary information to support the evaluation of patients’ self‑control competency in disease management.