Can physiotherapy in an interdisciplinary pain rehabilitation setting improve physical function? A long-term mixed methods follow-up study.

Purpose: The aim of this study was to describe chronic pain patients' perception of their physical function and treatment factors for improving or maintaining physical function long-term after the completion of an Interdisciplinary Pain Rehabilitation Program (IPRP) and to compare physical function before, directly after and at long-term follow-up (16-20 months after treatment).

Materials and methods: Patients with severe nonmalignant chronic pain, participating in an IPRP at a specialist clinic, were eligible for inclusion in a convergent mixed methods study. Quantitative data included aerobic capacity, level of physical activity (PA) and self-efficacy for exercise. Qualitative data were collected through semi-structured interviews.

Results: The qualitative analysis resulted in one theme: Orientation change and two categories: Permission to feel self-worth and Reclaiming life, which illuminated factors that enabled a sustained increase in PA. The quantitative data (n = 11) showed a significantly increased maximal oxygen uptake (VO₂max) from 2.46 l/min (SD = 0.9) at baseline to 2.63 l/min (SD = 0.9, p = .03) on completion of the program. VO₂max was sustained at long-term follow-up (2.56 l/min (SD = 1.0, p = .24).

Conclusion: This study indicates that an orientation change process through an IPRP can lead to increased physical function and a sustainable level of PA. Furthermore, it highlights the importance of a person-centered approach to enable sustainable change in patients with chronic pain.