Stefan Elbers

177 AGRIPPA: protocol for an RCT INTRODUCTION Background and Rationale Chronic pain is a major contributor to worldwide disability, affecting approximately 20% of the global population (Breivik et al., 2006; Treede et al., 2015; Vos et al., 2012). For many patients, ongoing or recurrent pain severely impacts their physical, social, and mental health, as it interrupts ongoing activities and thereby continuously interferes with daily life functioning. Over time, this impacts patients’ sense of self and quality of life (Vlaeyen et al., 2016). Inmany cases, there is no monodisciplinary treatment available that can cure the persisting pain. Instead, the multifaceted nature of chronic pain, including biomedical as well as psychological and social factors, often requires a comprehensive treatment approach focusing on improving daily life functioning rather than reducing pain (Foster et al., 2018; Gatchel et al., 2014; Linton & Shaw, 2011). To realize this, interdisciplinary multimodal pain therapy (IMPT) progammes have evolved that aim to support patients in learning to live a meaningful life irrespective of pain. These progammes share a biopsychosocial orientation toward chronic pain and often include both neuroscientific models of pain physiology as well as (cognitive) behavioural treatment principles (Gatchel et al., 2014; Morley & Williams, 2015). Although the effectiveness of IMPT progammes has been well established (Banerjee & Argáez, 2017; Kamper et al., 2014; Morley et al., 2013; Schatman, 2012), maintaining the positive effect of the treatment on patients’ daily lives over time remains a major challenge (Morley, 2008; Turk & Rudy, 1991). The problem of relapse is not unique to the domain of pain treatment but has been observed across all health behaviour domains (e.g. Middleton et al., 2013; Miller, 2012). In response, many treatment progammes have added relapse prevention strategies that aim to preserve treatment gains over time (e.g. Fleig et al., 2013; Kwasnicka et al., 2016). In the context of chronic pain treatment, examples of such strategies include self-practice exercises (Silvemark et al., 2014; Smeets et al., 2008), booster sessions (Mangels et al., 2009; Tavafian et al., 2011), or encouragement of patients to take notes during treatment (Monticone et al., 2016; Persson et al., 2012). However, the integration of these particular strategies within the treatment progamme as well as an underlying theoretical rationale regarding how it may prevent relapse are often not described in clinical studies. Moreover, the effectiveness of these behaviour regulation strategies remains unknown because they are usually evaluated as a part of the full progamme or with a limited follow-up period.