Hsiao Y.-Y.Shih C.-L.Yu W.-H.Hsieh C.-H.CHING-LIN HSIEH2020-04-082020-04-0820150962-9343https://www.scopus.com/inward/record.uri?eid=2-s2.0-84931025408&doi=10.1007%2fs11136-014-0771-z&partnerID=40&md5=10c78e71c608262aef01cd56ee743653https://scholars.lib.ntu.edu.tw/handle/123456789/483844Purpose: The Medical Outcome Study Short Form 36 (SF-36) is one of the most commonly used questionnaires for monitoring the Health-Related Quality of Life (HRQOL) of opioid-dependent patients. However, the unidimensionality and reliability of the SF-36 have not been verified in opioid-dependent patients. The aim of this study was to examine the unidimensionality and to improve the test reliability of the SF-36 for use in opioid-dependent patients. Methods: A total of 583 opioid-dependent patients were recruited in the study. Unidimensionality was examined by conducting unidimensional Rasch analysis. Item fit statistics and principle component analysis were used to check the item-model fit in each of the eight subscales of the SF-36. Reliability was evaluated by applying both unidimensional and multidimensional Rasch analyses. Results: After three misfitting items were excluded, the remaining items of each subscale in the SF-36 represented a single construct. The test reliabilities (0.80–0.87) yielded by the multidimensional approach were much higher than those (0.68–0.82) produced by the unidimensional approach. Conclusion: The remaining 32 items of the SF-36 are appropriate for evaluating the HRQOL in opioid-dependent patients in terms of unidimensionality. Additionally, the test scores produced by the multidimensional approach were more accurate than those obtained by the unidimensional approach. ? 2014, Springer International Publishing Switzerland.[SDGs]SDG3adolescent; adult; female; human; male; middle aged; Opioid-Related Disorders; prospective study; psychometry; quality of life; questionnaire; reproducibility; standards; Taiwan; total quality management; validation study; young adult; Adolescent; Adult; Female; Humans; Male; Middle Aged; Opioid-Related Disorders; Prospective Studies; Psychometrics; Quality Improvement; Quality of Life; Questionnaires; Reproducibility of Results; Taiwan; Young Adultjournal article10.1007/s11136-014-0771-z250991982-s2.0-84931025408