Estimation of HbA_1c after weight loss using a beta-regression for an economic evaluation of a behavioural weight management programme from the GLoW trial: a methodological study

BACKGROUND:In economic evaluations, average intervention effects are usually applied to a population. However, this fails to reflect the change in the distribution of HbA 1c1cMETHODS:The Glucose Lowering through Weight Management (GLoW) trial evaluated the effectiveness of a diabetes education and weight-loss intervention against a standard diabetes education programme. Adults diagnosed with type 2 diabetes within 3 years were recruited from Clinical Commissioning Groups across 159 sites in England from July 20, 2018, to July 22, 2018. Ethics approval (18/ES/0048) and participant informed consent were obtained. Considering the between-treatment-arm difference in HbA 1c1c1cFINDINGS:The trial recruited 577 participants (mean age 60 years; 278 [53%] female, 247 [47%] male; 474 [91%] white ethnic background). Applying heterogeneous HbA 1c1cINTERPRETATION:Alternative regression specification methods should be considered when evaluating the cost-effectiveness of interventions if the key intervention outcomes are not normally distributed. However, this alternative method requires further investigation to conclude its appropriateness in evaluating cost-effectiveness in different contexts. FUNDING:National Institute for Health and Care Research (NIHR) Programme Grants for Applied Research Programme (Reference Number RP-PG0216-20010).