Psychometric evaluation of a Theoretical Domains Framework based questionnaire on community pharmacists' pharmaceutical care service for breastfeeding women

Background There is a lack of validated Theoretical Domains Framework (TDF) based instruments to investigate barriers and facilitators for community pharmacists (CPs) to provide effective care for breastfeeding women. Aim The aim of this study was to evaluate the psychometric properties of a TDF-14 (v2) based questionnaire to identify barriers and facilitators faced by Turkish CPs in provision of pharmaceutical care to breastfeeding women. Method This observational study was carried out among CPs in T & uuml;rkiye. After generating the English form of the questionnaire, translation and cultural adaptation of the questionnaire, an expert panel and pilot study were conducted. Data were collected through an online survey between October 2023 and January 2024. The psychometric properties of the questionnaire were tested by performing test-retest reliability, confirmatory factor analysis (CFA), and internal consistency analysis. Results The test-retest reliability analysis (n = 30) indicated that the intraclass correlation coefficient values of each domain were between 0.75 and 0.96 (p < 0.001). Four hundred and sixteen CPs completed the questionnaire (response rate: 37.5%). Out of a total of 36 items, six items were excluded. The final questionnaire covered 13 out of the 14 TDF (v2) domains. Chi square/degree of freedom (chi(2)/df), comparative fit index (CFI), root mean square error of approximation (RMSEA), and standardized root mean square residual (SRMR) were 2.01, 0.96, 0.05, and 0.04; respectively. Cronbach's alpha values of each domain ranged from 0.63-0.90. Conclusion This TDF-based questionnaire is a valid and reliable tool for evaluating CPs' enablers and barriers to providing pharmaceutical care to breastfeeding women.