WASHINGTON – The postpartum readmission rate increased over a recent 8-year period from 1.72% to 2.16%, with readmitted patients more likely to be publicly insured and more likely to have multiple comorbidities, a multistate analysis shows.
The rise in readmissions from 2004 to 2011 “isn’t solely explained by the increasing cesarean rate,” and appears to be significantly influenced “by increasing maternal comorbidities,” said Dr. Mark A. Clapp, who reported preliminary findings at the annual meeting of the American College of Obstetricians and Gynecologists.
Dr. Clapp and his coinvestigators analyzed postpartum readmissions occurring in the first 6 weeks after delivery in women in California, Florida, and New York – 3 states whose combined 1 million deliveries a year represent approximately a quarter of all deliveries in the United States. Of approximately 8 million deliveries identified over the study period, 6 million were eligible for analysis.
Medical and surgical readmission rates are used in various specialties as indicators of quality and linked to reimbursement, but “very little is known about readmissions in obstetrics,” he said.
The researchers identified deliveries and postpartum readmissions in state inpatient databases and compared maternal, pregnancy, and delivery characteristics of women who were readmitted with those who weren’t readmitted. This included both “primary” indications for readmissions and “associated diagnoses” listed for these patients.
The most common primary indication for readmission, they found, was wound infection or breakdown (15.5%), followed by hypertensive disease (9.3%), and psychiatric illness (7.7%). The most common associated diagnosis among readmitted patients was psychiatric disease, followed by hypertensive disease.
Women who were readmitted “were more likely to have comorbidities across the board,” said Dr. Clapp, a resident at Brigham and Women’s Hospital, Boston. The readmitted women had higher rates of all “associated diagnoses” listed in the state databases, from asthma and diabetes to obesity and thyroid disease, but the most significant differences were in the rates of hypertensive disease, psychiatric disease, and substance abuse.
Regarding mode of delivery, 37.2% of those who were readmitted had undergone a cesarean delivery versus 32.9% of those not readmitted. Patients who were readmitted also were more likely to have had a multiple gestation, preterm labor, or a placental abnormality.
The majority of readmitted patients in the retrospective cohort study were publicly insured: 54% versus 42%. Readmitted patients also were more likely to be older, with a mean age of 36 years, compared with 28 years in the non-readmitted group. They also were more likely to be black (19% of readmitted patients versus 14% of non-readmitted). Over 50% of readmissions occurred in the first week.
The impact of cesarean delivery on readmission risk needs further investigation, Dr. Clapp said, noting that cesarean delivery was an inconsistent predictor of readmission. In Florida, for instance, patients who had cesarean deliveries in 2011 were actually less likely to be readmitted than those who delivered vaginally.
Psychiatric comorbidities also need to be better understood, as does the “influence of increasing maternal comorbidities, which I suspect is driving the increase in readmissions, rather than the mode of delivery,” Dr. Clapp said.
“Hopefully, we can build a body of evidence to either support or refute the use of readmissions as a measure of quality in our field,” he said.
Dr. Clapp and his coauthors reported no relevant financial disclosures. The study was funded by an ACOG health policy grant.