Naturalistic trial of nudging patients and clinicians in the Norwegian sickness absence clinics: a study protocol for the NSAC Nudge Study.

Introduction: Common mental disorders and musculoskeletal disorders are the leading causes of sickness absence and disability. There has been a rise in work-focused clinical interventions and studies investigating whether general clinical services can increase employment and reduce sickness absence. However, evidence supporting a clinical approach to preventing sickness absence and improving return to work remains limited. This is a protocol for a multicentre randomised controlled trial, the Norwegian Sickness Absence Clinic Nudge Study (NSAC Nudge Study), which aims to investigate the effect of including questionnaires on motivation for work, barriers for return to work and work environment to patients and the provision of a summary of responses to clinicians prior to consultation, on return to work, prevention of sickness absence and alleviation of symptoms.

Methods: The NSAC Nudge Study is a multicentre naturalistic randomised controlled trial conducted at five outpatient clinics admitting patients on-or at risk of sickness absence due to common mental-and/or musculoskeletal disorders in Northern Norway. The study commenced on 6 September 2021 and aimed to recruit 1100 patients. Recruitment concluded on 12 January 2023, at which point 1171 patients had been enrolled. The patients were randomised in equal proportions to receive either of two questionnaires prior to treatment; a questionnaire mapping health factors only, or a questionnaire mapping health factors and factors related to motivation for work, barriers for return to work and motivation for work. Data sources include survey data from both patients and clinicians, as well as 20 years of retrospective and prospective data from national registries on healthcare utilisation, sickness absence, employment and benefits.

Analyses: In this protocol, we describe a trial aiming to facilitate and improve return to work, prevention of sickness absence and alleviation of symptoms for patients with common mental health and/or musculoskeletal disorders through a nudge. The study findings will serve as validation of an implemented programme for this patient group and inform decisions on how the programme may be adapted to increase its efficacy.

Ethics And Dissemination: The study has been approved by the Regional Committee for Medical Research (REC North), grant number #285 489. Results from the study will be communicated to the participating HelseIArbeid outpatient clinics and other relevant stakeholders and disseminated through scientific publications and presentations.

Trial Registration Number: NCT05006976.