In clinical trials, treatment with fenofibrate did not reduce the incidence of major cardiovascular events (MCVE) in patients with type 2 diabetes mellitus (T2DM). However, treatment effects reported by trials comprise patients who respond poorly and patients who respond well to fenofibrate. Our aim was to use statistical modeling to estimate the expected treatment effect of fenofibrate for individual patients with T2DM.
To estimate individual risk, the FIELD risk model, with 5-year MCVE as primary outcome, was externally validated in T2DM patients from ACCORD and the SMART observational cohort. Fenofibrate treatment effect was estimated in 17,142 T2DM patients from FIELD, ACCORD, and SMART. Individual treatment effect, expressed as absolute risk reduction (ARR), is the difference between treated and untreated MCVE risk. Results were stratified for patients with and without dyslipidemia (i.e., high triglycerides and low LDL cholesterol).
External validation of the FIELD risk model showed good calibration and moderate discrimination in ACCORD (C-statistic 0.67 [95% CI 0.65–0.69]) and SMART (C-statistic 0.66 [95% CI 0.63–0.69]). Median 5-year MCVE risk in all three studies combined was 6.7% (interquartile range [IQR] 4.0–11.7) in patients without (N = 13,224) and 9.4% (IQR 5.4–16.1%) in patients with (N = 3,918) dyslipidemia. The median ARR was 2.15% (IQR 1.23–3.68) in patients with dyslipidemia, corresponding with a number needed to treat (NNT) of 47, and 0.22% (IQR 0.13–0.38) in patients without dyslipidemia (NNT 455).
In individual patients with T2DM, there is a wide range of absolute treatment effect of fenofibrate, and overall the fenofibrate treatment effect was larger in patients with dyslipidemia. The method of individualized treatment effect prediction of fenofibrate on MCVE risk reduction in T2DM can be used to guide clinical decision making.
