OBJECTIVE: To investigate predictors of improvement in observed ability to manage activities of daily living as an outcome of rehabilitation in fibromyalgia.

METHODS: Exploratory analyses used data from the Interdisciplinary Rehabilitation and Evaluation Programme for Patients with Chronic Widespread Pain (the IMPROvE study); a randomized controlled trial including 191 females with fibromyalgia randomized (1:1) to rehabilitation or a waiting list. The primary outcome was observed activities of daily living ability evaluated with the Assessment of Motor and Process Skills (AMPS) 6 months post-intervention.

RESULTS: Overall, 38.7% of subjects were AMPS responders, i.e. having a clinically meaningful improvement in AMPS activities of daily living ability measures at 6 months post-intervention. In the exploratory analysis, only 4 baseline variables out of the 52 analysed showed a statistically significant interaction with treatment allocation (at the 0.05 level) indicating possible predictive value. Statistical analyses that used continuous variables dichotomized at the median suggested a predictive value of a low intake of weak and strong analgesics, and a high score of current pain and total score on the Pain Detect Questionnaire.

CONCLUSION: The results of this exploratory study suggest that several subgroups of patients, specifically those with a low baseline intake of weak and strong analgesics, and more pronounced clinical signs of central sensitization, may gain most clinical benefit from specialized rehabilitation when the outcome of interest is improvement in observed activity of daily living ability.