SAN DIEGO – The amount of pain medication a women requires in the hospital after a cesarean delivery was an accurate predictor of postdischarge needs, and could provide guidance to tailor home prescriptions, reducing the amount of unused opioids left after recovery, according to a new study.

Jenna Emerson, MD, and her colleagues also found that more than half of the opioid medications prescribed for home postcesarean use went untaken, and that one in five women used no opioid medication after leaving the hospital.

“Prescribing an appropriate amount of postcesarean opioids is a tangible way obstetricians could impact the public health crisis of opioid abuse,” Dr. Emerson and her coauthors wrote in the abstract accompanying the study’s presentation at the annual clinical and scientific meeting of the American College of Obstetricians and Gynecologists.

The prospective cohort study, one of two awarded the Donald F. Richardson Prize at the meeting, looked at how much opioid medication was used by women while they were inpatients, and also asked women to keep track of how much medication they used at home, to see if one could predict the other.

The pilot study enrolled 100 women who had a postdelivery inpatient stay of less than 8 days, who spoke English, and who had given birth to a live viable infant. The study’s statistical analysis looked for relationships not only between inpatient and outpatient use of opioids, but also between patient characteristics and level of opioid use in the hospital and at home.

A total of 76 women completed follow-up, said Dr. Emerson, who is a fourth-year ob.gyn. resident at Brown University, Providence, R.I. One patient was excluded because she was on high opioid doses for addiction treatment before delivery, and her postdelivery opioid requirements represented a clear outlier in the data.

The investigators used medical record data to determine opioid requirements as inpatients after cesarean delivery. For standardization of different strengths of opioids, use was expressed by using Mean Morphine Equivalents (MME). Baseline patient demographic characteristics and comorbidities were also obtained from medical record review.

Patients were asked to track their home opioid use for 2 weeks postdischarge, and also received a follow-up phone call at the end of their first 2 weeks at home.

Inpatient opioid use was divided into tertiles according to low (less than 40 MME), medium (41-70 MME), and high (greater than 70 MME) use. Overall, the group’s mean opioid use in the final 24 hours before discharge was 59 MME, an amount Dr. Emerson said was equivalent to about eight tablets of oxycodone/acetaminophen or 12 tablets of hydrocodone/acetaminophen.

Most patients (89%) went home with a prescription for oxycodone/acetaminophen, and the mean number of pills prescribed per patient was 35. For the original group of 100 patients, this meant that prescriptions were written for 3,150 oxycodone/acetaminophen tablets, 162 hydrocodone/acetaminophen tablets, and 139 oxycodone tablets.

Home use over the first 2 weeks postdischarge was a mean 126 MME, or the equivalent of about 17 oxycodone/acetaminophen tablets. A total of 39% of women reported they had used less than half of their opioid medication; 21% had used all or required more opioids, and 20% had used at least half of their opioids. One in five patients (20%) had not taken a single opioid tablet after discharge from the hospital, and only 2 of the 75 women were still using opioids at the time of the 2-week follow-up call, Dr. Emerson said.

This means there was a total of 1,538 tablets of unused prescription opioid medication left in the homes of the 75 women included in the final analysis, Dr. Emerson said.

When the investigators compared inpatient and outpatient opioid use, they found that 26 women (34.7%) had been in the lowest tertile of inpatient opioid use. These women also had the lowest mean MME at home, using 53 MME in the first 2 weeks post discharge. The middle tertile for inpatient use used a mean 111 MME at home, while the highest used 195 MME (analysis of variance P less than .001).

Higher outpatient opioid use was seen in patients with a history of psychiatric comorbidities (MME 172 vs. 103 for no psychiatric comorbidities; P = .046). Other factors associated with numerically higher use that did not reach statistical significance included breastfeeding status (MME 197 for no breastfeeding, 112 for breastfeeding; P = .068) and insurance status (MME 154 for public, 95 for private; P = .058).

Patients’ mean age was 30.3 years; 63% of participants were Caucasian, 5% were black, and 19% identified their ethnicity as Hispanic. Patients were about evenly divided between having public and private insurance, and most (72%) had some post-high school education. Just 5% had a prior history of drug use or abuse, and about half (49%) were having a repeat cesarean delivery. Three quarters were breastfeeding their infants.

Unused opioid prescriptions are a significant contributor to the pool of opioids available for diversion and recent work has shown that up to 23% of opioids prescribed are used for “nonmedical” purposes, Dr. Emerson said. Since cesarean deliveries are the most commonly performed major surgery in the United States, the opportunity to reduce the number of opioids available for diversion is significant, she said.

“Opioid prescription use after cesarean delivery should be tailored to patient needs,” she said, calling for larger studies to validate and expand on the findings.

Dr. Emerson reported having no outside sources of funding and no relevant financial disclosures.

koakes@frontlinemedcom.com

On Twitter @karioakes

Postcesarean outpatient opioid needs predicted by inpatient use