Ann Arbor, MI—Painkiller prescriptions filled after surgery tend to be about four times what patients actually use after common procedures, a new study reports.

That is a problem, according to the article in JAMA Surgery, because of the strong correlation between size of prescription and how many opioids actually are ingested. In fact, University of Michigan researchers point out that the number of pills received has a greater influence on opioid use than pain scores, the intensity of the surgical procedure, or personal factors.

The remedy, according to the study team, is for prescribers to use real-world information about surgical-patient opioid use to guide how they write the scripts. The researchers also urge better education of surgical patients on safe disposal of opioids, which often are diverted and misused.

The retrospective, population-based analysis of the quantity of opioids prescribed and patient-reported opioid consumption was conducted at 33 health systems in Michigan, using a sample of adults aged 18 years and older undergoing surgery. Patients were included if they were prescribed an opioid after a common surgery between January 1, 2017, and September 30, 2017.

The 2,392 participants, who had a mean age of 55 years and were 57% women, underwent one of 12 procedures.

Results indicated that the quantity of opioid prescribed was significantly higher than patient-reported opioid consumption (median, 30 pills; IQR, 27-45 pills of hydrocodone/acetaminophen, 5/325 mg, vs. 9 pills; IQR, 1-25 pills; P <.001).

“The quantity of opioid prescribed had the strongest association with patient-reported opioid consumption, with patients using 0.53 more pills (95% CI, 0.40-0.65; P <.001) for every additional pill prescribed,” according to the researchers, who added, “Patient-reported pain in the week after surgery was also significantly associated with consumption but not as strongly as prescription size.”

The study detailed how, compared with patients reporting no pain, patients used a mean (SD) 9 (1) more pills if they reported moderate pain, and 16 (2) more pills if they reported severe pain (P <.001).

“Using patient-reported opioid consumption to develop better prescribing practices is an important step in combating the opioid epidemic,” study authors concluded.

“It’s striking to see the major discrepancy between prescribed amount and the amount patients actually take,” added senior author Joceline Vu, MD, a surgical resident and research fellow at Michigan Medicine, U-M’s academic medical center. “This is not a phenomenon of a few outlier surgeons—it was seen across the state, and across many operations.”

While the median number of pills prescribed was 30, the median number actually used was nine. Patients who reported severe pain after surgery took 16 more pills, on average, than those with controlled pain.

The study found that tobacco users tended to use more opioids after surgery, while the older a patient was, the fewer opioid pills they tended to require. In terms of risk associated with different procedures, patients undergoing hernia repair—whether through open surgery or minimally invasive surgery—used the most opioids among the 12 surgeries studied. The fewest pills were used by patients who had removal of the appendix or thyroid.

“In what we tell patients about what kind of pain to expect after surgery, and how many pills we give, we set their expectations—and what the patient expects plays a huge role in their post-operative pain experience,” explained first author Ryan Howard, MD, a surgical resident. “So, if they get 60 pain pills, they think they have to take many of them.”

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