Validity and reliability of quality of recovery-35 Thai version: a prospective questionnaire-based study

BACKGROUND The quality of patients' recovery following surgery and anesthesia has been a matter of focus and concern over the past decade. The Quality of Recovery-40 (QoR-40) questionnaire was developed and validated for post-anesthesia patient evaluation. The QoR-40, however, is English-based and was tested and validated in Caucasian patients, a population that is culturally and behaviorally different from the Thai population. The objective of this study was to translate and modify the original English-language QoR-40 into the Thai language and evaluate the Quality of Recovery-35 Thai version for measuring health outcomes in Thai patients after surgery and anesthesia. METHODS Translation was performed according to internationally recognized translation standards to ensure the integrity of the translated version. Consistent with the recommendations of 25 anesthesiologists, five questions from the original QoR-40 were excluded. The 35-item questionnaire was then translated into the Thai language and renamed the Quality of Recovery-35 Thai version (Thai QoR-35). Overall, 43 outpatients and 53 inpatients rated their health and recovery status using three patient evaluation tools: 100-mm Visual Analogue Scale-Recovery (VAS-R), six-item Activities of Daily Living (ADL) questionnaire, and Thai QoR-35. RESULTS Overall, 90 % of patients took <10 min to complete the Thai QoR-35 questionnaire. The Thai QoR-35 and VAS-R showed good convergent validity (r = 0.84, P < 0.001). Discrimination validity was supported by a significant difference in mean scores for recovery among the Thai QoR-35, VAS-R, and ADL when compared between outpatients and inpatients (P < 0.01) and also between baseline and postoperative values (P < 0.001). The Thai QoR-35 also demonstrated good reliability with high internal consistency at three time points (Cronbach's alpha = 0.88, 0.89, 0.91, respectively; P < 0.01) and a split-half reliability coefficient of 0.65 (P < 0.001). CONCLUSION Thai QoR-35 is a valid, reliable tool for evaluating quality of recovery in Thai patients.