# A cluster randomised controlled trial, process and economic evaluation of two large-scale quality improvement interventions embedded with a national clinical audit to improve the care for young adults with type 2 diabetes (EQUIPD2): study protocol

## TL;DR

This study tests two interventions to improve diabetes care for young adults in England using a national audit system.

## Contribution

The study introduces scalable feedback facilitation interventions integrated with a national audit to improve diabetes care for young adults.

## Key findings

- The interventions will be evaluated for their impact on HbA1c levels and care processes in young adults with type 2 diabetes.
- The study will assess the cost-effectiveness and equity impacts of the interventions.
- Findings will inform large-scale implementation strategies for diabetes care improvement.

## Abstract

Young adults (18–39 years) with type 2 diabetes have an increased loss of life expectancy and a greater risk of complications such as retinopathy, sexual health problems and foot disease than people diagnosed with type 2 diabetes later in life. Globally, there are increasing numbers of young adults with type 2 diabetes. Evidence describes both care (for example, prescribing) and improvement practices (for example, case management) that improve outcomes for people with type 2 diabetes.

The National Diabetes Audit (NDA) provides feedback describing variation in both care and outcomes in young adults. Feedback facilitation can increase the effectiveness of audit feedback. Working collaboratively between researchers, audit providers, patients, clinicians and policy-makers, we have developed two feedback facilitation interventions deliverable at scale across England. We will evaluate whether theory-informed virtual educational materials with email support (low-intensity intervention) and / or virtual workshops (medium-intensity intervention) improve outcomes for young adults with type 2 diabetes.

An efficient, pragmatic cluster randomised controlled trial using routine data with a theory-informed process and economic evaluation. The interventions will be delivered alongside the NDA to primary care networks (small groups of general practices) across England. Our primary outcome will be HbA1c level at 16-months post-randomisation in young adults with type 2 diabetes and baseline HbA1c ≥ 58 mmol/mol. Secondary outcomes assess the proportion with an HbA1c below recommended thresholds, prescription consistent with recommendations and delivery of recommended care processes. We will investigate impacts on equity. We will explore implementation, engagement and fidelity through interviews, observations, documentary analysis and surveys. An economic evaluation will estimate cost-effectiveness and budget impact.

Our study embeds a further evaluation within the NDA, strengthening its role as a national diabetes learning health system. Our findings will have implications for intervention providers and funders seeking improvement in care and outcomes, and for our understanding of large-scale implementation strategies.

ISRCTN 52205353 Registered 12 March 2025. https://www.isrctn.com/ISRCTN52205353.

The online version contains supplementary material available at 10.1186/s13012-025-01479-8.