BACKGROUND
In contrast to other high-resource countries, the United States has experienced increases
in the rates of severe maternal morbidity. In addition, the United States has pronounced
racial and ethnic disparities in severe maternal morbidity, especially for non-Hispanic
Black people, who have twice the rate as non-Hispanic White people.
OBJECTIVE
This study aimed to examine whether the racial and ethnic disparities in severe maternal
morbidity extended beyond the rates of these complications to include disparities
in maternal costs and lengths of stay, which could indicate differences in the case
severity.
STUDY DESIGN
This study used California's linkage of birth certificates to inpatient maternal and
infant discharge data for 2009 to 2011. Of the 1.5 million linked records, 250,000
were excluded because of incomplete data, for a final sample of 1,262,862. Cost-to-charge
ratios were used to estimate costs from charges (including readmissions) after adjusting
for inflation to December 2017. Mean diagnosis-related group–specific reimbursement
was used to estimate physician payments. We used the Centers for Disease Control and
Prevention definition of severe maternal morbidity, including readmissions up to 42
days after delivery. Adjusted Poisson regression models estimated the differential
risk of severe maternal morbidity for each racial or ethnic group, compared with the
non-Hispanic White group. Generalized linear models estimated the associations of
race and ethnicity with costs and length of stay.
RESULTS
Asian or Pacific Islander, Non-Hispanic Black, Hispanic, and other race or ethnicity
patients all had higher rates of severe maternal morbidity than non-Hispanic White
patients. The largest disparity was between non-Hispanic White and non-Hispanic Black
patients, with unadjusted overall rates of severe maternal morbidity of 1.34% and
2.62%, respectively (adjusted risk ratio, 1.61; P<.001). Among patients with severe maternal morbidity, the adjusted regression estimates
showed that non-Hispanic Black patients had 23% (P<.001) higher costs (marginal effect of $5023) and 24% (P<.001) longer hospital stays (marginal effect of 1.4 days) than non-Hispanic White
patients. These effects changed when cases, such as cases where a blood transfusion
was the only indication of severe maternal morbidity, were excluded, with 29% higher
costs (P<.001) and 15% longer length of stay (P<.001). For other racial and ethnic groups, the increases in costs and length of stay
were smaller than those observed for non-Hispanic Black patients, and many were not
significantly different from non-Hispanic White patients. Hispanic patients had higher
rates of severe maternal morbidity than non-Hispanic White patients; however, Hispanic
patients had significantly lower costs and length of stay than non-Hispanic White
patients.
CONCLUSION
There were racial and ethnic differences in the costs and length of stay among patients
with severe maternal morbidity across the groupings that we examined. The differences
were especially large for non-Hispanic Black patients compared with non-Hispanic White
patients. Non-Hispanic Black patients experienced twice the rate of severe maternal
morbidity; in addition, the higher relative costs and longer lengths of stay for non-Hispanic
Black patients with severe maternal morbidity support greater case severity in that
population. These findings suggest that efforts to address racial and ethnic inequities
in maternal health need to consider differences in case severity in addition to the
differences in the rates of severe maternal morbidity and that these differences in
case severity merit additional investigation.
Key words
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Article info
Publication history
Published online: March 04, 2023
Accepted:
February 28,
2023
Received in revised form:
February 1,
2023
Received:
January 13,
2023
Footnotes
This study is partially supported by the National Institutes of Health/Eunice Kennedy Shriver National Institute of Child Health and Human Development (grant numbers R01 HD084819 and R01 HD099197).
The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the U.S. government.
The authors report no conflict of interest.
Cite this article as: Phibbs CM, Kristensen-Cabrera A, Kozhimannil KB, et al. Racial/ethnic disparities in costs, length of stay, and severity of severe maternal morbidity. Am J Obstet Gynecol MFM 2023;XX:x.ex–x.ex.
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Published by Elsevier Inc.
