Stefan Elbers

31 Evaluating IMPT programmes over time healthcare professionals from various disciplines that provided the interdisciplinary treatment; (d) a single facility where each patient received treatment (Gatchel et al., 2014). This last criterion excluded care-network settings, but not multicenter trials. Although structured teammeetings are considered an important aspect of IMPT programmes (Kaiser et al., 2017), we did not include this as an inclusion criterion, because we expected that not all studies would explicitly report this. Our outcomes were based on the criteria developed by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) and included physical functioning, pain interference, depression, anxiety, emotional functioning, anger, self-efficacy, social functioning and pain intensity (see protocol for rationale) (Dworkin et al., 2005; Turk et al., 2003). The study had to include at least one outcome that was measured at two time points: prior to treatment and at least 12 months after the intervention was completed. Studies that focused on patients with post- surgical pain or cancer pain, as well as studies that solely included patients on the basis of a specific comorbidity (e.g. depression) were excluded. Articles published in other languages than English, German or Dutch were also excluded. Study Selection, Data Extraction and Risk of Bias All study selection, data extraction and risk of bias assessments were independently performed by at minimum two different researchers (UK and SE for articles in German, SK, SE and MK for articles in other languages). Researchers used pre-tested forms and compared their input to reach consensus. In case of disagreement, the study was discussed with other researchers (HW and RS) for a final decision. Study selection was performed in two rounds. In the screening round, abstracts were screened using the Rayyan software package (Ouzzani et al., 2016). Subsequently, full text studies were assessed on all eligibility criteria. From the extraction round onwards, we considered patient cohorts - not journal articles - as our primary unit of analysis. In case of multiple articles describing the same cohort, we combined these sources to construct a complete overview of the development over time. The first published article that met our eligibility criteria was used as the primary source and we consulted additional sources, such as protocols or follow-up studies if they contained additional relevant information. If the information sources did not contain all data items of interest, we did not contact the study authors but coded this as ‘not reported’ in our dataset. Our data extraction form included all items from the template for intervention description and replication (TIDieR) checklist to describe the content of the treatment programme in detail (supplementary 2) (Hoffmann et al., 2014). Risk of Bias was assessed with the Joanna Briggs Institute Checklist for Case Series, which included 10 criteria (Moola et al., 2017). A response of 'no' to any one of the items resulted in a high risk