Are the changes in observed functioning after multi-disciplinary rehabilitation of patients with fibromyalgia associated with changes in pain self-efficacy?

Abstract

Objective: To examine the hypothesis that change in pain self-efficacy is associated with observed and self-reported activity, pain intensity, catastrophizing, and quality of life after multi-disciplinary rehabilitation of fibromyalgia patients.

Design: In-depth analyses of secondary outcomes of a randomized-controlled trial.

Subjects: Women (N = 187) with fibromyalgia.

Methods: Outcomes were Pain Self-Efficacy, Assessment of Motor and Process Skills (AMPS), SF-36 Physical Function (SF-36-PF), pain intensity, and SF-36 Mental Composite Score (SF-36-MCS) to assess quality of life and pain catastrophizing. Individual and group associations between outcomes were examined.

Results: Individual changes in pain self-efficacy were not associated with changes in observed activity: AMPS motor (r_s = 0.08, p = 0.27) and process (r_s = 0.12, p = 0.11), not even in those patients with a clinically relevant improvement in observed functioning (38.5%), and only weakly or moderatly with changes in SF-36-PF; (r_s = 0.31, p < 0.0001), SF-36-MSC; (r_s = 0.41, p < 0.0001), and pain catastrophizing (r_s = −0.31, p < 0.0001). No differences in pain self-efficacy were observed between the rehabilitated group and controls (difference: 1.61; 95% CI: −0.84 to 4.06; p = 0.24). However, a subgroup (34%) had a clinically relevant improvement in pain self-efficacy. This group was younger (mean age 41.4 vs. 45.8, p = 0.01), more recently diagnosed (1.8 vs. 2.8 years, p = 0.003), but had an unresolved welfare situation (59% vs. 40%, p = 0.02).

Conclusion: The main hypothesis was falsified, as there was no association between pain self-efficacy and actual performance of activity. The relation to functioning may be limited to perceived, cognitive-emotional aspects, as indicated by the weak to moderate correlations to the self-reported measures.

Implications for Rehabilitation

• Improvement in observed activity post multi-disciplinary rehabilitation was not associated with change in pain self-efficacy.

• Patients performed better after rehabilitation, but did not perceive to have improved their capacity.

• The relationship between pain self-efficacy and functioning may be limited to cognitive-emotional aspects rather than actual activity.

• Both observational and self-reported measures should be included in evaluating outcomes of rehabilitation for patients with fibromyalgia.

Keywords:

• Fibromyalgia
• pain self-efficacy
• multi-disciplinary rehabilitation
• observed activity performance
• self-reported perceived capacity

Acknowledgements

The authors would like to thank the additional members of the IMPROvE study group: OT, Ph.D. Assistant Professor Eva Wæhrens and OT, MSc, PhD Student Cecilie von Bülow and the rest of the good staff at the Parker Institute, for their help and support. We would also like to acknowledge the colleagues in Research Unit of Clinical Nursing at Copenhagen University Hospital, for our scientific discussions and their constructive feedback on the manuscript, and the good colleagues at the Research Unit for General Practice at University of Southern Denmark. Finally, we gratefully recognize all the patients participated in the study.

Disclosure statement

The study was investigator initiated and none of the authors has any conflict of interest in regards to the contents in this study.

Funding

The study was financially supported by The Novo Nordisk Foundation, Grant number: NNF12OC0002145; Aase and Ejnar Danielsen’s Foundation, Grant number: 10-000994; The Oak Foundation, Grant number: OCAY-13-309; The Lundbeck Foundation, Grant number: 51/2013; and the University of Southern Denmark, Faculty PhD scholarship, ID number: 36/103-270162.