Performance of the UKPDS Outcomes Model 2 in a contemporary UK type 2 diabetes trial cohort

Objectives: The UKPDS Outcomes Model developed using 30-year (1977-2007) data from the UKPDS is widely used for health outcomes’ projections and economic evaluations of therapies for patients with type 2 diabetes (T2D). However, its reliability for contemporary UK T2D populations is unclear. We assessed the performance of version 2 of the model (UKPDS-OM2) using data from the ASCEND study, which followed participants with diabetes in the UK between 2005 and 2017. Methods: The UKPDS-OM2 was used to predict the occurrence of myocardial infarction (MI), other ischaemic heart disease (Other IHD), stroke, cardiovascular death and other death among the 14 569 participants with T2D in the ASCEND study, all without previous cardiovascular disease at study entry. Calibration (comparison of predicted and observed year-on-year cumulative incidence over 10 years) and discrimination (c-statistics) of the model were assessed for each endpoint. The percentage error in event rates at year 7 (mean duration of follow-up) was used to quantify model bias. Results: The UKPDS-OM2 substantially over-predicted MI, stroke, cardiovascular death and other death over the 10 year follow-up period (by 149%, 42%, 269% and 52% respectively, at year 7). Discrimination of the model for MI and Other IHD (c-statistics 0.58 and 0.60 respectively) was poorer than that for other outcomes (c-statistics ranging from 0.66 to 0.72). Conclusions: The UKPDS-OM2 substantially over-predicted risks of key cardiovascular outcomes and death in people with T2D in ASCEND. Appropriate adjustments or a new model may be required for assessments of long-term effects of treatments in contemporary T2D cohorts.