Hospital-level variation in rates of postpartum hemorrhage in California

Background To examine the extent of hospital-level variation in risk-adjusted rates of postpartum hemorrhage (PPH). Study design and Methods We performed a cross-sectional study examining live births in 257 California hospitals between 2011 and 2015 using linked birth certificate and maternal discharge data. PPH was measured using International Classification of Diseases Codes version 9. Mixed-effects logistic regression models were used to examine the presence and extent of hospital-level variation in PPH before and after adjustment for patient-level risk factors and select hospital characteristics (teaching status and annual delivery volume). Risk-adjusted rates of PPH were estimated for each hospital. The extent of hospital variation was evaluated using the median odds ratio (MOR) and intraclass correlation coefficient (ICC). Results Our study cohort comprised 1,904,479 women who had a live birth delivery hospitalization at 247 hospitals. The median, lowest, and highest hospital-specific rates of PPH were 3.48%, 0.54%, and 12.0%, respectively. Similar rates were observed after adjustment for patient and hospital factors (3.44%, 0.60%, and 11.48%). After adjustment, the proportion of the total variation in PPH rates attributable to the hospital was low, with a MOR of 2.02 (95% confidence interval [CI]: 1.89-2.15) and ICC of 14.3% (95% CI: 11.9%-16.3%). Discussion Wide variability exists in the rate of PPH across hospitals in California, not attributable to patient factors, hospital teaching status, and hospital annual delivery volume. Determining whether differences in hospital quality of care explain the unaccounted-for variation in hospital-level PPH rates should be a public health priority.