Predictors for health improvement in patients with fibromyalgia: a 2-year follow-up study.

Fibromyalgia (FM) has a high impact on all aspects of health. The effect from interventions is usually small and characterized by uncertainty. Better insight in predictors for improved health is essential. The present study aimed to understand predictors for patient global impression of change and changes in overall health. Data from a longitudinal cohort of recently diagnosed FM patients (n = 203) were used. Within this cohort, patients were pre-randomized to either a multidisciplinary (n = 108) or an, aerobic exercise (n = 47) program, or usual care (n = 48). Only a limited number of patients started with the programs (n = 86) or participated fully, i.e., attended >70 % of the scheduled sessions (n = 68). Patients completed questionnaires covering all components of the International Classification of Functioning, Disability and Health (ICF) bio-psycho-social model of health, which was used as a framework to structure potential predictors. Principal component analysis was used to reduce the number of potential predictors. Regression analyses were used to explore associations with the outcome variables. Principal component analysis yielded five factors representing areas that covered different ICF components and chapters. "Being employed" and "full participation in a program" were independently associated with a better global impression of change. A longer duration of FM-related symptoms and more limitations in physical areas of body functions were independently associated with a worse impression of overall health. Higher levels of perceived limitations in physical and mental activities were associated with "starting to participate in a program" and with "full participation in a program." Recently diagnosed FM patients that report fewer physical limitations may experience more improvement in health if they are at work and have a positive attitude towards participating in an offered health-care intervention. These findings give support to an active rather than to a care-avoiding attitude of health-care workers in their contacts to these patients.