Are Rates of Chronic Opioid Use Increased Post-THA and TKA?

In a new study published online in JAMA Internal Medicine, researchers at the Stanford University School of Medicine examined rates of and risk factors for chronic opioid use among post-surgical patients.¹

Rates of opioid use and related overdose deaths have soared in recent years, and the prolonged use of these drugs carries a major health and economic burden.² While several studies have pointed to surgery as a potential risk factor for chronic use, they pertained mostly to patients who were already using opioids and whose procedures were expected to result in significant post-surgical pain. 

“By contrast, the incidence and risk factors for chronic opioid use among opioid-naive patients undergoing less painful procedures are not as well understood,” wrote the authors of the new study.

Using data from administrative health claims, they investigated the incidence of chronic use within the year following surgery among 641 941 adult patients who had not filled an opioid prescription within the year prior to surgery. 

The study included 11 common procedures that are not typically expected to result in long-term pain, including: total knee arthroplasty (TKA), total hip arthroplasty (THA), laparoscopic cholecystectomy, open cholecystectomy, laparoscopic appendectomy, open appendectomy, cesarean delivery, FESS, cataract surgery, transurethral prostate resection (TURP), and simple mastectomy.

The main outcome of chronic opioid use was defined as “having filled 10 or more prescriptions for more than 120 days’ supply of an opioid in the first year after surgery, excluding the first 90 postoperative days,” according to the paper. 

The outcomes of the surgery group were compared with those of a reference group consisting of 18 011 137 opioid-naïve nonsurgical patients during a similar time period. The authors also examined multiple possible risk factors for chronic use, including age and sex, history of substance abuse or psychiatric disorders, and previous use of certain medications.

The results show that cataract surgery, laparoscopic appendectomy, FESS, and TURP were the only procedures not associated with increased incidence of chronic opioid use. For the other procedures, odds ratios were as follows:

• TKA (OR, 5.10; 95% CI, 4.67-5.58; P < .001)
• Open cholecystectomy (OR, 3.60; 95% CI, 2.80-4.62; P < .001)
• THA (OR, 2.52; 95% CI, 2.11-3.01; P < .001)
• Simple mastectomy (OR, 2.65; 95% CI, 2.28-3.08; P < .001)
• Laparoscopic cholecystectomy (OR, 1.62; 95% CI, 1.49-1.76; P < .001)
• Open appendectomy (OR, 1.69; 95% CI, 1.24-2.31; P = .001)
• Cesarean delivery (OR, 1.28; 95% CI, 1.12-1.46; P < .001)

The risk factors found to be associated with chronic use post-surgery included male sex, age older than 50 years, and preoperative history of drug abuse, alcohol abuse, depression, benzodiazepine use, or antidepressant use, suggesting that a certain subset of patients–elderly male patients, for example–may be especially at risk.

“We surmise that chronic opioid use following surgery occurs because surgery may unmask an individual’s susceptibility toward long-term opioid use,” they wrote. They note the results should not discourage people from having needed surgeries, as the overall risk of increased use is still low–less than 0.5% for most procedures. Rather, physicians should closely monitor patients’ opioid use in the period after surgery.  

References

1. Sun EC, Darnall B, Baker LC, Mackey S. Incidence of and risk factors for chronic opioid use among opioid-naive patients in the postoperative period. 2016. JAMA Intern Med; doi:10.1001/jamainternmed.2016.3298
2. U.S. National Institutes of Health: National Institute on Drug Abuse. Overdose death rates. Last updated online December 2016. Accessed on July 12, 2016.  https://www.drugabuse.gov/related-topics/trends-statistics/overdose-death-rates

This article originally appeared on Clinical Pain Advisor