Development of a Disease-Specific Health Literacy Scale for Chronic Obstructive Pulmonary Disease (COPD)

The aim of this study is to develop a health literacy scale specific to Chronic Obstructive Pulmonary Disease (COPD) and to evaluate its validity and reliability. This methodological study was conducted between July 2024 and May 2025 with 160 patients diagnosed with COPD who were admitted to the inpatient wards and outpatient clinics of the Department of Pulmonology at a university hospital. Data were collected using the "Patient Information Form," the "COPD-Specific Health Literacy Scale," the "COPD Assessment Test," the "Medical Research Council Dyspnea Scale," and the "Health Literacy Scale (HLS-14)." The scale development process included the following steps: literature review, item pool generation, expert consultation and content validity assessment, pilot testing of the draft scale, and subsequent validity and reliability analyses. The draft version of the "COPD-Specific Health Literacy Scale," initially consisting of 35 items, was evaluated for content validity by six experts, yielding a Content Validity Ratio (CVR) of 0.67. A pilot study was then conducted with a 32-item version of the scale on 150 participants, after which items not aligning with the scale structure were removed based on exploratory factor analysis. The final version consisted of 16 items across 3 subscales and was applied to a sample of 160 patients for the main study. Confirmatory factor analysis indicated good model fit with the following indices: χ²/df: 1.228; GFI: 0.921; AGFI: 0.890; CFI: 0.985; RMSEA: 0.060; SRMR: 0.046; NFI: 0.924; TLI: 0.981; IFI: 0.985; RFI: 0.907. The test-retest reliability of the scale was assessed using the Intraclass Correlation Coefficient (ICC), indicating a high level of agreement between responses over time (ICC: 0.813; p<0.001). The Cronbach's alpha coefficient for the overall scale was 0.91, with subscale coefficients ranging from 0.73 to 0.93. This study concluded that the COPD-Specific Health Literacy Scale is a valid and reliable instrument.