For the study, the researchers reviewed information from the 2011 Nationwide Inpatient Sample. According to MedPage Today, the database is the largest publicly available resource on all-payer inpatient care in the U.S. It features data from 1,049 short-term, nonfederal hospitals in 46 states, allowing for nationally representative estimates.
The researchers assessed low-risk childbirths among women ages 16 to 34. They did not include data from women who had any of 23 maternal comorbidities, nor did they review data from women with any of 15 risk factors for pregnancy. The researchers also excluded hospitals that had fewer than 100 low-risk childbirths and certain types of hospitalizations, including those with incomplete data, those involving transferred patients and those from hospitals with outlier costs.
Overall, they reviewed 274,917 childbirths across 463 hospitals.
The researchers found that the estimated average facility cost in 2011 for a low-risk childbirth hospital stay ranged from $1,189 to $11,986. According to the study, the median cost for such a stay was $4,215.
The researchers noted that certain factors were associated with greater costs, including comparatively low childbirth volumes, low rates of Medicaid-covered deliveries, long hospital stays, rural areas and hospitals operated by not-for-profits or a nonfederal entity. Overall, hospital characteristics factored into about 13% of variation in facility cost estimates.
Meanwhile, according to the study, rates for C-section childbirths ranged from 2% to 39% across the 463 hospitals, with a median rate of 10.6%. The researchers noted that while the average facility cost estimate was about $432.28 greater for hospitals with higher rates of C-sections, the difference was not statistically significant after they accounted for the mean duration of hospital stay. The finding suggests "that longer length of stay might be one of the main mechanisms through which [C-section] delivery rate influenced hospital facility costs," they wrote.
The study also found that the rate of serious maternal morbidity varied between 0% and 4.8%. According to the researchers, there was a substantial link between such rates and facility cost estimates, with each 1% increase in the rate associated with an increase of $296.32 in the cost of a maternity stay.
The researchers noted that there are few data about variation in childbirth costs, which is the leading reason for hospital admission in the U.S. The researchers wrote, "With nearly 4 million births in the United States each year, the large variation in estimated hospital facility costs points to an opportunity for cost containment." They added, "Experience from existing payment and delivery system reforms could inform strategies to reduce costs in obstetric care."
However, Xiao Xu, of the Yale School of Medicine and an author of the study, noted that the research "mostly focused on the cost side of the issue, but what really matters is the value of care."
Xu also noted that "the data [the researchers] have access to only has limited information" and does not detail all the possible factors that influence the cost of childbirth. Further, Xu said that ongoing discussions about health care payment and delivery reform "could potentially have a big impact on how care is delivered" (Frieden, MedPage Today, 7/7).