Development and validation of the patient trust in community pharmacists (TRUST-Ph) scale: Results from a study conducted in Thailand

Abstract

Background: The quality of the pharmacist-patient relationship has been examined in various perspectives, for example patient satisfaction. Trust is another concept within which the quality of the relationship might be examined and is critical in contemporary pharmacy practice. Objective: To develop and validate a scale to measure patient trust in community pharmacists. Methods: A 5-dimension conceptual model of trust, which includes fidelity, competence, honesty, confidentiality, and global trust, was originally used for scale development. Candidate items were generated and revised using expert reviews, focus group discussion, and think aloud method in the first phase. The items and their revisions were tested in 2 successive phases. Data were collected from 2 convenience samples of 400 each in Songkhla and Yala provinces of Thailand. Factor analysis and item analysis were used to determine dimensions and refine items of the trust scale. Internal consistency and construct validity of the scale were determined. Results: At first, exploratory factor analysis showed that the most interpretable solution consisted of 2 factors labeled Benevolence and Technical Competence. The Technical Competence had unsatisfactory internal consistency (Cronbach's alpha < 0.80). An improvement was made in the later phase and another dimension, Communication, was identified. The final 30-item scale, namely TRUST-Ph, with 3 dimensions had good internal consistency (Cronbach's alpha = 0.84-0.91). The scale exhibited a strong positive association with satisfaction with pharmacy services (r = 0.70, P < .001). It also showed positive associations between the level of patient trust and other patient-pharmacist aspects. Conclusions: The developed scale (TRUST-Ph) to measure patient trust in community pharmacists had relatively high validity and reliability. It had 3 dimensions, which were Benevolence, Technical Competence, and Communication. The TRUST-Ph scale can be potentially used as a measure of patient-reported outcome for community pharmacist services. © 2008 Elsevier Inc. All rights reserved.