Validation of risk equations for complications of type 2 diabetes (RECODe) using individual participant data from diverse longitudinal cohorts in the U.S.

Abstract

OBJECTIVE We sought to validate Risk Equations for Complications of Type 2 Diabetes (RECODe) among diverse populations. RESEARCH DESIGN AND METHODS We compared risk predictions from RECODe equations and from two alternative risk models (UK Prospective Diabetes Study OutcomesModel 2 [UKPDS OM2] and American College of Cardiology/American Heart Association Pooled Cohort Equations) to observed outcomes in two studies: The Multi-Ethnic Study of Atherosclerosis (MESA, n = 1,555 adults with type 2 diabetes,median follow-up 9.1 years) and the Jackson Heart Study (JHS, n = 1,746 adults with type 2 diabetes, median follow-up 8.0 years). Outcomes included nephropathy by multiple measures (microalbuminuria, macroalbuminuria, renal failure, end-stage renal disease, and reduction in glomerularfiltration rate), moderate to severe diabetic retinopathy by Airlie House classification, fatal or nonfatalmyocardial infarction, fatal or nonfatal stroke, congestive heart failure, and all-cause mortality. RESULTS RECODe equations for microvascular and cardiovascular outcomes had C-statistics for discrimination ranging from 0.71 to 0.85 in MESA and 0.64 to 0.91 in JHS for alternative outcomes. Calibration slopes in MESA ranged from 0.62 for a composite nephropathy outcome, 0.83-1.04 for individual nephropathy outcomes, 1.07 for retinopathy, 1.00-1.05 for cardiovascular outcomes, and 1.03 for all-causemortality. Slopes in JHS ranged from0.47 for retinopathy, 0.97-1.16 for nephropathy, 0.72-1.05 for cardiovascular outcomes, and 1.01 for all-causemortality. The alternativemodels had C-statistics 0.50-0.72 and calibration slopes 0.07-0.60. CONCLUSIONS RECODe equations improved risk estimation for diverse patients with type 2 diabetes, as compared with two commonly used alternatives.