Maternal infection is a common complication of childbirth, yet little
is known about the extent to which infection rates vary among hospitals. We
estimated hospital level risk-adjusted maternal infection rates (RAIR) in a
large sample of U.S. hospitals and explored associations between RAIR and
select hospital features.
This retrospective cohort study included hospitals in the Perspective
database with more than 100 deliveries over two years. Using a composite
measure of infection, we estimated and compared RAIR across hospitals using
hierarchical generalized linear models. We then estimated the amount of
variation in RAIR attributable to hospital features.
Of the 1,001,189 deliveries at 355 hospitals, 4.1% were complicated
by infection. Women ages 15-19 were 50% more likely to experience infection
than those ages 25-29. Rupture of membranes >24 hours (OR 3.0, 95% CI
3.24, 3.5), unengaged fetal head (OR 3.11. 95% CI 2.97, 3.27), and blood
loss anemia (OR 2.42, 95% CI 2.34, 2.49) had the highest odds ratios among
comorbidities commonly found in patients with infection. RAIR ranged from
1.0% to 14.4% (median 4.0%, IQR 2.8%-5.7%). Hospital features such as
geographic region, teaching status, urban setting and higher number of
obstetric beds were associated with higher infection rates, accounting for
14.8% of the variation observed.
Obstetric RAIR vary among hospitals, suggesting an opportunity to
improve obstetric quality of care. Hospital features such as region, number
of OB beds and teaching status account for only a small portion of the
observed variation in infection rates.