Stefan Elbers

85 Self-management for patients with chronic pain system (i.e. bones, joints, tendons or muscles). Although self-management principles have been incorporated in multicomponent treatment programmes (e.g. Meng et al., 2011; Du et al., 2017), and self-management skill training can overlap with other types of interventions with different underlying theoretical approaches (e.g. action planning in the Health Action Process Approach, (Schwarzer, 2017), we were only interested in generic interventions that focusedonimprovingbehavioural adjustmentbytrainingself-management skills.Therefore, the intervention had to address at least one of the following five self-management skills: problem-solving, decision making, resource utilization, forming a partnership with a health care provider and taking action (Lorig and Holman, 2003). In addition, the intervention had to include both an element of information transfer on self-management principles (e.g. education session or lecture) and a training component where self-management skills were actually rehearsed or performed. The intervention had to be focused on improving generic self-management skills, rather than on training disease-specific skills (e.g. joint protection techniques). The study had to include a control intervention that was not a self- management intervention. Lastly, the study had to include at least one of the following outcome measures: physical function, self-efficacy, pain intensity, or physical activity. For physical function, we included self-report instruments that measured the degree of interference that chronic pain had on daily life activities and social participation. For self-efficacy, we included self-report instruments that measured the level of confidence in patients’ capabilities to perform daily life tasks or activities. Pain intensity measures were included if they solely measured the degree of pain experienced on a scale from low to high intensity. Composite scores of various moments of pain intensity were also included (e.g. Von Korff scales), as well as sum scores of pain intensity for each tender point. For physical activity, we included both self-report instruments and activity trackers that provided an indication of how often certain types of physical activities were performed. We excluded studies with samples that solely consisted of patients with osteoarthritis, because Kroon et al. (2014) had recently published a systematic review of self-management interventions for this subgroup. When a composite sample included patients with osteoarthritis, at least 50% of the sample had to consist of patients with other forms of chronic musculoskeletal pain. In addition, interventions that were designed to improve self-management in the context of pre-operative training, post-operative rehabilitation or palliative care were excluded, as we expected that this would lead to substantial heterogeneity regarding disease management and coping. To avoid heterogeneity, studies were also excluded if they only included patients on the basis of a specific comorbidity (e.g. psychiatric or obese patients), or if they combined the self-management intervention with other chronic pain treatment modalities (e.g. graded activity, exposure in vivo, Acceptance and Commitment Therapy, interdisciplinary pain management programmes). We also excluded e-health interventions that did not include any form of face-to-face contact