Group Medical Visits (GMVs) in primary care: An RCT of group-based versus individual appointments to reduce HbA1c in older people

Abstract

Introduction: Type 2 diabetes mellitus (T2DM) affects more than 1.1 million Canadians aged ≥65 years. Group Medical Visits are an emerging health service delivery method. Recent systematic reviews show that they can significantly reduce glycated haemoglobin (HbA1c) levels, but Group Visits have not been evaluated within primary care. We intend to determine the clinical effectiveness, quality of life and economic implications of Group Medical Visits within a primary care setting for older people with T2DM. Methods and analysis: A 2-year proof-of-concept, single-blinded (measurement team) randomised control trial to test the efficacy of Group Medical Visits in an urban Canadian primary care setting. Participants ≥65 years old with T2DM (N=128) will be equally randomised to either eight groups of eight patients each (Group Medical Visits; Intervention) or to Individual visits (Standard Care; Controls). Those administering cointerventions are not blinded to group assignment. Our sample size is based on estimates of variance (±1.4% for HbA1c) and effect size (0.9/1.4=0.6) from the literature and from our own preliminary data. Forty participants per group will provide a β likelihood of 0.80, assuming an α of 0.05. A conservative estimation of an effect size of 0.7/1.4 changes the N in the power calculation to 59 per group. Hence, we aim to enrol 64 participants in each study arm. We will use intention-to-treat analysis and compare mean HbA1c (% glycosylated HbA1c) (primary outcome) of Intervention/Control participants at 12 months, 24 months and 1 year postintervention on selected clinical, patient-rated and economic measures.