Interference with work in fibromyalgia - effect of treatment with pregabalin and relation to pain response

Abstract

Abstract Background Clinical trials in chronic pain often collect information about interference with work as answers to component questions of commonly used questionnaires but these data are not normally analysed separately. Methods We performed a meta-analysis of individual patient data from four large trials of pregabalin for fibromyalgia lasting 8-14 weeks. We analysed data on interference with work, inferred from answers to component questions of Fibromyalgia Impact Questionnaire (FIQ), Short Form 36 Health Survey, Sheehan Disability Scale, and Multidimensional Assessment of Fatigue, including "How many days in the past week did you miss work, including housework, because of fibromyalgia?" from FIQ. Analyses were performed according to randomised treatment group (pregabalin 150-600 mg daily or placebo), pain improvement (0-10 numerical pain rating scale scores at trial beginning vs. end), and end of trial pain state (100 mm visual analogue pain scale [VAS]). Results Comparing treatment group average outcomes revealed modest improvement over the duration of the trials, more so with active treatment than with placebo. For the 'work missed' question from FIQ the change for patients on placebo was from 2.2 (standard deviation [SD] 2.3) days of work lost per week at trial beginning to 1.9 (SD 2.1) days lost at trial end (p /= 50% pain improvement and from 1.9 (SD 2.2) days to 0.73 (SD 1.4) days (p /= 50% pain improvement and a pain score Conclusions Effective pain treatment goes along with benefit regarding work. A reduction in time off work >1 day per week can be achieved in patients with good pain responses.