Cost-effectiveness of Strategies for Postpartum Glucose Intolerance Testing

Abstract

Background Abnormal glucose metabolism after gestational diabetes mellitus can persist postpartum. This study compares the cost and effectiveness of 4 postpartum glucose intolerance screening strategies and their influencing variables. Methods A decision model compared 4 screening strategies: Fasting capillary glucose test (FCG) 24–72 hours postpartum (inpatient FCG) alone (strategy 1); Inpatient FCG plus 2-hour oral glucose tolerance test (OGTT) (strategy 2) or plus home FCG testing (strategy 3) at 4–12 weeks postpartum; No screening (strategy 4). Clinical probabilities and costs were obtained from institutional data, the literature, retail prices, and reimbursement data. The primary outcome was the per-patient cost and effectiveness of detecting diabetes and prediabetes (i.e., disease) and the incremental cost-effectiveness ratio (ICER) between strategies. Effectiveness was the proportion of patients with disease detected. Sensitivity analyses examined parameter uncertainty and variance on primary outcome. Results The base case cost and effectiveness per strategy ranged from $1167 to $1330 and 0%–25%, respectively. Strategy 3 was the most effective and expensive strategy compared to strategy 2 (ICER $837), and remained so when < 36% of patients completed the 2-hour OGTT and when the sensitivity of home FCG testing for detecting diabetes was > 39%. Strategy 2 was more effective and expensive than strategy 1 (ICER $571). Limitations Our model underestimates the cost of a missed case by limiting the horizon to 1 year because of the available data. This is appropriate for our study perspective, but future study is needed to estimate the effect of a longer time horizon on model outcomes. Conclusion Home FCG testing offers a reasonable alternative to the 2-hour OGTT when adherence to the 2-hour OGTT is low. This model serves as a tool to guide postpartum glucose intolerance screening protocols, minimizing missed opportunities for diagnosis and early intervention.