To evaluate the association between opioid use and treatment outcome (symptom severity, quality of life [QOL]) after a brief interdisciplinary fibromyalgia treatment program (FTP).
Subjects (n = 971) with fibromyalgia participated in the FTP. They filled out the Fibromyalgia Impact Questionnaire (FIQ) and the Short Form-36 Health Status Questionnaire (SF-36) at baseline and 6 to 12 months after the FTP. Post-treatment changes in FIQ and SF-36 scores were compared after stratifying the participants into opioid user and non-opioid user groups.
A total of 236 patients (24.3%) were opioid users. Compared with non-opioid users, the opioid users had worse symptom severity measured using FIQ total score (p < .001) and all subscales at baseline and post treatment, as well as worse QOL measured using all SF-36 subscales and physical and mental components. Comparison of least-square means of mean change of QOL between opioid users and non-opioid users after analysis of covariance adjusted patient characteristics and baseline scores showed that the FIQ subscale scores of physical impairment (p < .05), job ability (p < .05), and fatigue (p < .05) were significantly less improved in the opioid users compared with the non-opioid users. Moreover, the SF-36 subscale score of general health perception (p < .05) was significantly less improved in the opioid users compared with non-opioid users. However, post-treatment changes in mean scores for QOL subscale generally did not significantly differ in both groups.
Opioid use did not affect response to the FTP, as measured using the FIQ total score or SF-36 physical and mental component summary scores. Furthermore, the opioid user group showed less improvement in the FIQ subscale scores of physical impairment, job ability, and fatigue and in the SF-36 subscale scores of general health perception.