Severe and fatal obstetric injury claims in relation to labor unit volume.

Objective: To assess possible association between the incidence of approved claims for severe and fatal obstetric injuries and delivery volume in Denmark.

Design And Setting: A nationwide panel study of labor units.

Population: Claimants seeking financial compensation due to injuries occurring in labor units in 1995-2012.

Methods: Exposure information regarding the annual number of deliveries per labor unit was retrieved from the Danish National Birth Register. Outcome information was retrieved from the Danish Patient Compensation Association. Exposure was categorized in delivery volume quintiles as annual volume per labor unit: (10-1377), (1378-2016), (2017-2801), (2802-3861), (3862-6659).

Main Outcome Measures: Five primary measures of outcome were used. Incidence rate ratios of (A) Submitted claims, (B) Approved claims, (C) Approved severe injury claims (120% degree of disability), (D) Approved fatal injury claims, and (C+D) Combined.

Results: 1 151 734 deliveries in 51 labor units and 1872 submitted claims were included. The incidence rate ratios of approved claims overall, of approved fatal injury claims, and of approved severe and fatal injuries combined increased significantly with decreasing annual delivery volume. Face value incidence rate ratios of approved severe injuries increased with decreasing labor unit volume, but the association did not reach statistical significance.

Conclusion: High volume labor units appear associated with fewer approved and fewer fatal injury claims compared with units with less volume. The findings support the development towards consolidation of units in Denmark. A suggested option would be to tailor obstetric patient safety initiatives according to the delivery volume of individual labor units.