title: Interference with work in fibromyalgia: effect of treatment with pregabalin and relation to pain response.
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 < 0.01). For patients on 600 mg pregabalin the change was from 2.1 (SD 2.2) days to 1.6 (SD 2.0) days (p < 0.001). However, the change in days of work lost was substantial in patients with a good pain response: from 2.0 (SD 2.2) days to 0.97 (SD 1.6) days (p < 0.0001) for those experiencing >/= 50% pain improvement and from 1.9 (SD 2.2) days to 0.73 (SD 1.4) days (p < 0.0001) for those achieving a low level of pain at trial end (<30 mm on the VAS). Patients achieving both >/= 50% pain improvement and a pain score <30 mm on the VAS had the largest improvement, from 2.0 (SD 2.2) days to 0.60 (SD 1.3) days (p < 0.0001). Analysing answers to the other questions yielded qualitatively similar results.
  
  
  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.
authors.affiliation: Department of Occupational, Social and Environmental Medicine, University Medical Center Göttingen, Germany. sebastian.straube@googlemail.com
authors.forename: Sebastian
authors.initials: S
authors.lastname: Straube
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Moore
authors.forename: Jocelyn
authors.initials: J
authors.lastname: Paine
authors.forename: Sheena
authors.initials: S
authors.lastname: Derry
authors.forename: Ceri J
authors.initials: CJ
authors.lastname: Phillips
authors.forename: Ernst
authors.initials: E
authors.lastname: Hallier
authors.forename: Henry J
authors.initials: HJ
authors.lastname: McQuay
mesh_terms: D000041:Absenteeism; D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000700:Analgesics / Q000627:therapeutic use*; D017281:Cost of Illness; D005260:Female; D005356:Fibromyalgia / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology / Q000503:physiopathology; D010147:Pain Measurement; D000069583:Pregabalin; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D000700:Analgesics; D000069583:Pregabalin; D005680:gamma-Aminobutyric Acid