The analysis showed the opioid cessation rate at 18 months after surgery was 64% among those who used the pain medication before joint replacement, and 95% among those who did not.
Abuse of prescription opioids is a known culprit in the rise of the current opioid epidemic, which the CDC said claims 130 lives a day; researchers Florence et al, estimate the economic burden is $78.5 billion a year, including healthcare and addiction treatment costs and lost productivity.
One route to addiction that has received attention is the use of opioids to pain following joint replacement, but a new analysis shows that this phenomenon may not be what it seems. Patients who keep using opioids may not be those who took them for the first time after surgery, the researchers found, but instead are those who started using opioids for pain management before a joint replacement.
In their paper, appearing this week in Pain Medicine, authors from axailHealthcare and Vanderbilt University Medical Center, both in Nashville, Tennessee, and Brigham and Women’s Hospital, Boston, Massachusetts, evaluate health records from more than 34,700 patients who had hip, knee, or shoulder replacement in 2014-2015, to reveal patterns in opioid use both before and after surgery—and their relationship with cost.
The data show that patients who were taking opioids before joint replacement had longer lengths of stay, higher costs, and increased revision rates, which were related to the dose. These patients were defined as those who had at least 2 opioid fills at least 30 days apart in the 90 days prior to surgery.
Of the patients studied, 38% had hip replacement, 58% had knee replacement, and 4% had shoulder replacement. Of the group, 6043 (17.4%) used opioids prior to surgery, with an average daily dose of 32 mg. Findings showed:
- Those who took opioids prior to surgery had increased length of stay (incidence rate ratio = 1.03, CI = 1.02-1.05, P < .001), nonhome discharge (odds ratio [OR], 1.10, 95% CI = 1.00-1.21, P = .048), and 30-day unplanned readmission (OR = 1.43, 95% CI = 1.17- 1.74, P < .001).
- Opioid users prior to surgery had 35% higher rates of surgical site infection (HR = 1.35, 95% CI 1.14-1.59, P <.001), and 36% higher surgical revision risk in the 18 months after surgery (HR = 1.36, 95% CI = 1.15-1.62, P < .001).
- Surgical site infection risk and surgical revision risk both increased as opioid doses increased (HR = 1.46, 95% CI = 1.21-1.76; HR = 1.46, 95% CI = 1.20 to 1.78, respectively).
- The median medial spend for those using opioids before surgery was $1084 higher than those who did not (95% CI = $833-$1334) in the 365 days after discharge.
Data showed that 92% of surgical patients filled an opioid prescription within 45 days of surgery, but those who used opioids prior to joint replacement had an opioid cessation rate of 64% after 18 months, compared with 95% for those who had not used opioids prior to joint replacement.
This would raise questions about state policies that limit post-surgical opioid prescriptions to a 5- or 7-day supply. Based on these findings, the patients who struggle to limit opioid use after joint replacement would already have a 30-day supply of pain medication on hand.
The authors write that patients using opioids before joint replacement were more likely to already “have comorbid psychiatric disorders and to have incurred high costs in the year before surgery.”
While in-hospital spending differed little between those who used opioids prior to surgery and those who did not, the authors wrote, “We are led to suspect that the effects of preoperative opioid use on surgical outcomes are more likely to manifest in the postoperative period, because these patients were more frequently discharged to a location other than their preoperative home of record.”
In turn, these patients were more likely to be readmitted within 30 days, more likely to have surgical site infection within 90 days, and more likely to need a second surgery to repair or realign the implant.
How common is opioid use prior to joint replacement? One Veterans Administration study cited by the authors put the figure at 39.1%, while another study of a commercially insured population said the share is 17.6%.
Strategies to curtail opioid use prior to surgery may be in order, the authors say, given the rise of bundled payment models in this area of surgical care. “As healthcare payment models continue to shift toward accountable care organizations bearing the risk for patient outcomes and/or bundled payments for medical services, factors that directly affect costs will continue to grow in importance,” the authors write.