Cross-cultural adaptation and validation of the Persian version of the Physical Therapy Outpatient Satisfaction Survey

Abstract

Background/Aims Few satisfaction questionnaires have been available to physical therapists for use in an Iranian population. This study aimed to translate, culturally adapt and validate the Iranian version of the Physical Therapy Outpatient Satisfaction Survey. This was a methodological study in outpatients from the physiotherapy centres in Kerman, Iran. Methods In this study, a cross-sectional and prospective validation study design was used. The Persian version of this questionnaire was prepared using forward and backward translation. The test–retest reliability was examined through interclass correlation coefficient, and absolute reliability was assessed through minimal detectable change and standard error of measurement. Internal consistency reliability was assessed by the Cronbach's alpha coefficients. Concurrent criterion validity was evaluated by assessing the correlation between the subscales of the questionnaire and the global satisfaction index. Divergent validity was measured by comparing the Persian Physical Therapy Outpatient Satisfaction Survey with the visual analogue scale and with the Global Rating of Change. The Statistical Package for the Social Sciences (version 24) was used for statistical analysis. Results A total of 297 individuals completed the questionnaire, and after 5–7 days, 40 participants answered the questionnaire again. The interclass correlation coefficients for the total score of Persian Physical Therapy Outpatient Satisfaction Survey was 0.75 and for the subscales of enhancers, detractors, location and cost were 0.76, 0.79, 0.84 and 0.40 respectively. The coefficient for internal consistency reliability (Cronbach's alpha=0.73) was within the acceptable range. The standard error of measurement and minimal detectable change were 0.5 and 1.4 respectively. The correlation of Physical Therapy Outpatient Satisfaction Survey subscales with global satisfaction was relatively good except for the cost subscale. Divergent validity was significant and poor for the visual analogue scale, r=–0.11 (P=0.04), but non-significant for the Global Rating of Change, r=–0.04 (P=0.40). There were no floor and ceiling effects in the Physical Therapy Outpatient Satisfaction Survey questionnaire subscales scores. Conclusions Although measurement properties of the Physical Therapy Outpatient Satisfaction Survey did not fully achieve measurement properties, the authors believe that the Persian version of the Physical Therapy Outpatient Satisfaction Survey can be used among Persian-speaking outpatient populations.