Cost-effectiveness of a periodic fasting-mimicking diet programme in patients with type 2 diabetes: a trial-based analysis and a lifetime model-based analysis

The prevalence of type 2 diabetes continues to rise worldwide, which is associated with a decrease in quality of Life and an increase in healthcare costs. The aim of this study was to determine cost-effectiveness of a one year monthly 5-consecutive day fasting-mimicking diet (FMD) programme for patients with type 2 diabetes treated with lifestyle advice only or lifestyle advice plus metformin, compared to usual care. A trial-based cost-utility analysis with quality-adjusted life-years (QALYs) and healthcare costs was performed. These results were extrapolated to a lifetime horizon using the United Kingdom Prospective Diabetes Study Outcomes Model, predicting cardiovascular events and mortality. Cost-effectiveness acceptability curves were assessed, representing the probability of the FMD programme being cost-effective compared to usual care across a range of willingness-to-pay (WTP) thresholds per QALY. In the trial-based analysis (n = 92), QALYs were insignificantly lower (-0.04, 95% CI -0.10 to + 0.03), while healthcare costs were significantly higher (+ €2241, 95% CI + 182 to + 2660) in the FMD group. In contrast, from a lifetime horizon, QALYs were insignificantly higher in the FMD group (+ 0.16, 95% CI -1.16 to + 1.48) and costs were insignificantly higher as well (+ €1336, 95% CI -753 to + 3425), yielding an incremental cost-effectiveness ratio of €8369/QALY. Thus, in the lifetime analysis the probability of cost-effectiveness of the FMD programme was around 0.6 as compared to usual care at most WTP thresholds. The FMD programme does not appear to be cost-effective over the first year of its application in the context of the Dutch healthcare system. However, this conclusion should be interpreted with caution due to the small sample size. In the extrapolations of the lifetime model-based cost-effectiveness analysis, a gain in QALYs in the FMD group was seen and the FMD programme’ costs were largely offset by savings in the costs of diabetic complications. This suggests that adding an FMD programme to usual care may potentially be cost-effective in the long term. ClinicalTrials.gov: NCT03811587. Registered 22 January 2019.