The association between obstetric comorbidity index and delivery hospitalization associated cost: a nationwide population study in Taiwan

The obstetric comorbidity index (OCI) is well recognized as a validated tool for maternal risk adjustment in healthcare service and population-based researches. The aim of the study was to further investigate the association between OCI scores and medical cost during delivery hospitalization. A nationwide retrospective study was conducted by using Taiwan National Health Insurance Research Database released from the Ministry of Health and Welfare of Taiwan. Delivery hospitalization records during the period from 2017 to 2021 were retrieved. The OCI scores were calculated by summing the weights with all maternal conditions and their age at delivery. All the delivery hospitalizations were further categorized into five groups by the OCI scores: OCI = 0 or 1, OCI = 2, 3, 4 and OCI ≥ 5. The medical cost and length of stay (LOS) derived from each delivery hospitalization were also obtained from the claim data. Generalize estimating equation model was estimated to investigate the association between OCI and medical cost as well as LOS. All data analysis was conducted using SAS 9.4. There were 824,329 delivery hospitalizations identified for analysis. Among all, 292,612 childbirths were via cesarean delivery, yielding an average cesarean rate of 35.5% during the study period. The mean medical cost among vaginal and cesarean deliveries was 37,265 points and 51,015 points, respectively. The average LOS was 2.9 days for vaginal deliveries and 4.9 days for cesarean deliveries. After adjusting for all covariates, higher OCI score is significantly associated with higher predicted medical cost and LOS. Study results demonstrated positive relationship between OCI scores, LOS, and medical cost. The application of OCI can be expanded into estimation of the medical cost during delivery hospitalization. OCI could be considered one of the important factors in risk adjustment for payment for delivery hospitalization.