OBJECTIVES: The primary objective was to assess the impact of using ‘metformin plus sulphonylureas’ (Met+SU) in comparison with ‘metformin plus other oral anti-hyperglycaemic agents’ (Met+OHA) in patients with Type 2 Diabetes (T2D) on diabetes-associated secondary healthcare utilisation in the UK. The secondary objectives included investigating individual components of the primary objective. METHODS: This retrospective cohort study used data from the Clinical Practice Research Datalink (CPRD) linked to Hospital Episodes Statistics. Adults (≥40 years) with T2D initiated on dual therapy with Met+SU or Met+OHA following metformin monotherapy were identified during the period April 2003–March 2012 and comprised the two study cohorts. Propensity scores were estimated and Met+SU patients caliper matched to Met+OHA patients to balance the covariates (including HbA1C and duration of diabetes at baseline). Diabetes-associated secondary healthcare utilisation (inpatient admissions and outpatient visits) were measured from >6 months post-initiation of dual therapy until treatment change or end of follow-up. Outcomes were calculated as rate ratios (RR), adjusted for over dispersion using negative binomial regression and propensity score for covariates. RESULTS: