Process Evaluation of a Motivational Interviewing Intervention in a Social Security Setting: A Qualitative Study among Work-Disabled Patients.

Purpose Return to work (RTW) may be facilitated by motivational interviewing (MI), a counseling style designed to increase motivation towards behavior change. MI's relevance in a RTW context remains however unclear. Exploring how, for whom and in what circumstances MI works is therefore necessary. Methods Eighteen people (29-60 years; sick leave > 12 weeks) with low back pain (LBP) or medically unexplained symptoms (MUS) participated in a semi-structured interview after one MI consultation. We conducted a realist-informed process evaluation to explore MI's mechanisms of impact, its outcomes and how external factors may influence these. Data were coded using thematic analysis. Results Main mechanisms were supporting autonomy, communicating with empathy and respect, facilitating feelings of competence and focusing on RTW solutions instead of hindrances. Competence support was more salient among LBP patients, whereas MUS patients benefited more from empathy and understanding. External factors were mentioned to have impacted MI's effectiveness and/or the further RTW process, being personal (e.g. acceptance of the condition), work-related (e.g. supervisor support) and societal (e.g. possibility of gradual RTW). Conclusions These results stress the importance of self-determination theory's support for autonomy, relatedness and competence, together with a solution-focused approach when stimulating patients' engagement regarding RTW. These mechanisms' instalment during RTW counseling and their long-term impact depends on both personal and system-like external factors. Belgium's social security system's premise, based on control, might actually hinder RTW instead of facilitating it. Further longitudinal research could explore MI's long-term effects as well as its complex interaction with external factors.