Assessing hospital differences in low-risk cesarean delivery metrics in Florida

Background: Unnecessary cesarean deliveries lead to increased maternal and neonatal morbidities and mortalities. In 2020, Florida had a cesarean delivery rate of 35.9%, the third highest in the nation. An effective quality improvement strategy to reduce overall cesarean delivery rates is to decrease primary cesarean deliveries in low-risk births (nulliparous, term, singleton, vertex). Of note, 3 nationally accepted hospital measures of low-risk cesarean delivery rates include the nulliparous, term, singleton, vertex; Joint Commission; and Society for Maternal-Fetal Medicine metrics. Comparing metrics is necessary because accurate and timely measurement is essential to support multihospital quality improvement efforts to reduce low-risk cesarean delivery rates and improve the quality of maternal care.

Objective: This study aimed to assess differences in hospital low-risk cesarean delivery rates in Florida using 5 different metrics of low-risk cesarean delivery rate based on (1) risk methodology, nulliparous, term, singleton, vertex; Joint Commission; and Society for Maternal-Fetal Medicine metrics, and (2) data source, linked birth certificate and hospital discharge records and hospital discharge records only.

Study design: This was a population-based study of live Florida births from 2016 to 2019 to compare 5 approaches to calculating low-risk cesarean delivery rates. Analyses were performed using linked birth certificate data and inpatient hospital discharge data. The 5 low-risk cesarean delivery measures were defined as follows: nulliparous, term, singleton, vertex birth certificate; Joint Commission-linked used Joint Commission exclusions; Society for Maternal-Fetal Medicine-linked used Society for Maternal-Fetal Medicine exclusions; Joint Commission hospital discharge with Joint Commission exclusions; and Society for Maternal-Fetal Medicine hospital discharge with Society for Maternal-Fetal Medicine exclusions. Nulliparous, term, singleton, vertex birth certificate was based on data from birth certificates and not using linked hospital discharge data. Designated as nulliparous, term, singleton, vertex, it does not exclude other high-risk conditions. The second and third measures (Joint Commission-linked used Joint Commission exclusions and Society for Maternal-Fetal Medicine-linked used Society for Maternal-Fetal Medicine exclusions) use data elements from the full-linked dataset to designate nulliparous, term, singleton, vertex and excluded several high-risk conditions. The last 2 measures (Joint Commission hospital discharge with Joint Commission exclusions; and Society for Maternal-Fetal Medicine hospital discharge with Society for Maternal-Fetal Medicine exclusions) were based on data from hospital discharge data only and not using linked birth certificate data. These measures generally reflect term, singleton, and vertex because parity could not be assessed adequately on hospital discharge data. Hospital differences between these 5 measures were calculated overall and by neonatal intensive care unit level.

Results: Overall, the median of hospital low-risk cesarean rates decreased across the measures, from NTSV-BC 30.7%, to Joint Commission linked 29.1%, and Society for Maternal Fetal Medicine hospital discharge 29.2% with a large decrease to Joint Commission hospital discharge 19.4% and Society for Maternal Fetal Medicine hospital discharge 18.1%. A similar trend was seen by neonatal intensive care unit level. For each of the measures, level II had the highest median low-risk cesarean rates (nulliparous. term, singleton, vertex birth certificate) 32.7%, Joint Commission linked (31.4%), Society for Maternal Fetal Medicine linked: 31.1%, Society for Maternal Fetal Medicine hospital discharge 19.3%), except for level III Joint Commission hospital discharge (20.0%). A comparison of the median number of low-risk births overall and by neonatal intensive care unit level showed a decreasing number across the linked and hospital discharge measures. Again, a wide gap in low-risk cesarean delivery rates was identified between linked measures and hospital discharge measures. However, this gap narrowed as hospital rates increased.

Conclusion: Quality monitoring of low-risk cesarean delivery rates measured by the nulliparous, term, singleton, vertex metric using the birth certificate was fairly accurate and provided timely assessment for use by Florida hospitals. The nulliparous, term, singleton, vertex birth certificate rates were comparable with low-risk metrics using the linked data source. Overall, metrics used within the same data source had similar rates, with the Society for Maternal-Fetal Medicine metric having the lowest rates. Across data sources, metrics using hospital discharge data only resulted in substantially underestimated rates because of the inclusion of multiparous women and should be interpreted with caution.