Oral health improvement for nursing home residents through delegated remotivation and reinstruction (MundZaRR Study): study protocol of a cluster-randomised controlled trial

INTRODUCTION: Oral health and oral health-related quality of life (OHrQL) of residents in German long-term residential care (LRC) are poor. We will develop an evidence-based catalogue of interventions (‘Oral Health Toolbox’) and provide care-accompanying reinstruction and remotivation of nursing staff by dental assistants (DA). We hypothesise that such intervention will significantly improve OHrQL, daily oral hygiene/care behaviour and is cost-effective. METHODS AND ANALYSIS: A scoping review will be used to identify possible intervention components. Mixed methods will be used to identify barriers and enablers of oral hygiene and care in German LRC. The result will be the ‘Oral Health Toolbox’, a two-phased instrument supporting both initial intervention allocation to improve oral health/hygiene and reinstruction/remotivation. A two-arm clustered, randomised controlled trial (ratio of 1:1 via block randomisation) will be performed in LRC in Rhineland-Palatinate, Germany. Each nursing home represents a cluster. Based on a feasibility study, considering clustering and possible attrition, we aim at recruiting 618 residents in 18 clusters. In the intervention group, dentists will assign one or more intervention component from the box (phase 1). During follow-up, nursing staff will be reinstructed and remotivated by DA, who use the box to decide how to maintain the intervention (phase 2). In the control group residents will receive care as usual. The primary outcome, OHrQL, will be measured using the General Oral Health Assessment Index. Secondary outcomes include pain condition, general health-related quality of life, caries increment, oral/prosthetic hygiene and gingival status, incidence of dental emergencies and hospitalisations, and cost-utility/effectiveness. The endpoints will be measured at baseline and after 12 months. For our primary outcome, a mixed-linear model will be used within an intention-to-treat analysis. A process evaluation using mixed methods will be conducted alongside the trial. ETHICS AND DISSEMINATION: Ethical approval by the University of Kiel was granted (D480/18). TRIAL REGISTRATION NUMBER: NCT04140929.