Evaluating lay health worker programmes for diabetes, integrating health related, social and environmental sustainability outcomes. A protocol for development of a Core Outcome Set

Background:Health systems face increasing strain from ageing populations, rising prevalence of diabetes, and shortages in the healthcare workforce, highlighting the need for sustainable models of community‑based care. Lay health workers (LHWs) is a potential strategy to support adults living with diabetes, yet evaluations of LHW programmes remain inconsistent, with wide variation in reported outcomes and limited attention to sustainability dimensions. Objective:This protocol describes the development of a Core Outcome Set (COS) for evaluating LHW programmes for adults with diabetes, integrating health‑related as well as social and environmental sustainability outcomes. Methods:The COS development process follows COMET-initative guidance and includes scoping and outcome identification through a systematic review of LHW interventions for diabetes (Tomas Pantoja et al. 2022) and a targeted literature search on sustainability‑related outcomes. Stakeholder groups includes LHWs, people living with diabetes, healthcare professionals, managers, and researchers. A two‑ round Delphi survey, with an optional third round, will be conducted using a six‑point Likert scale and a 70% consensus threshold. A final online consensus meeting will determine the outcomes to be included in the COS. Data will be analysed using thematic qualitative methods and descriptive statistics. Expected Outcomes:The resulting COS will provide a standardised set of outcomes for evaluating LHW programmes for diabetes, enabling improved comparability across studies and supporting more robust assessments of their clinical, social, and environmental impacts. Ethics:The study is approved by the Norwegian Agency for Shared Services in Education and Research (SIKT), reference 954611.