Prediabetes Tests for Predicting Progression to Diabetes: A Meta-Analysis and Cost-Effectiveness Evaluation

Background: The natural history of type 2 diabetes may begin when normoglycemia changes to prediabetes. However, the progression from prediabetes to diabetes can be prevented. Each test for identifying prediabetes uses different detection methods and may predict the progression to diabetes differently. The aim of this study was to evaluate the cost for every future case of diabetes detected as prediabetes by capillary glucose, fasting plasma glucose, oral glucose tolerance test, and glycated hemoglobin (A1c), and the glycemic assessment for prediction of progression to diabetes.

Methods: A meta-analysis of published cohort studies with enough data in the articles to estimate sensitivity and specificity to predict diabetes comparing the subjects with prediabetes in relation to normoglycemic subjects at baseline measurement was conducted. The meta-analysis was followed by a cost-effectiveness analysis.

Results: The combined sensitivities were: capillary glucose 62%, fasting plasma glucose 63%, A1c 67%, oral glucose tolerance test 70%, and the combination of fasting plasma glucose and A1c 83%. At the highest prevalence of prediabetes (
120 mg/dl postprandial capillary glucose), the cost by case detected by the combination of fasting plasma glucose and A1c is cheaper than the A1c alone and the glucose tolerance test, and more expensive than the capillary glucose and the fasting glucose alone.

Conclusions: We recommend the capillary glucose and the combination of fasting plasma glucose and A1c tests to identify prediabetes which will progress to diabetes. In order to save budget, screening could be performed first with capillary glucose, and after diagnosing, with fasting glucose and A1c performed simultaneously.