High overdose risk score should drive discussion, but is not indicative of surgical ineligibility

A user-friendly tool that analyzes current and past prescription drug use may help orthopedic surgeons determine if a patient is at risk for a prescription drug overdose after total knee arthroplasty (TKA), researchers reported.

Patients with a preoperative overdose risk score (ORS) of ≥300, as calculated with the NarxCare platform, had statistically significantly higher odds of prolonged hospital length of stay (LOS), discharge to a facility that was not their home, all-cause 90-day readmission, and emergency department (ED) visits, all of which were confirmed by propensity score matching, according to Nicolas S. Piuzzi, MD, of the Cleveland Clinic Foundation, and co-authors.

Specifically, for patients with an ORS of 300 to 399, versus those with an ORS of 0 (prescription naïve) there were significantly higher odds of:

  • Prolonged LOS: odds ratio 2.03 (95% CI 1.46-2.82. P<0.001).
  • Non-home discharge: OR 2.01 (95% CI 1.37-2.94, P<0.001).
  • All-cause 90-day readmission: OR 1.56 (95% CI 1.01-2.42, P<0.001).
  • ED visits: OR 1.62 (95% CI 1.11-2.38, P=0.01).

Of course, the odds were even higher for all of those outcomes for patients with ORS ≥500, they wrote in JAMA Network Open, adding that “our results associating certain prescription drug use patterns with higher odds of postoperative adverse outcomes may serve to identify individuals at increased risk of adverse postoperative outcomes and trigger a discussion of potential risks.”

But the authors stressed that surgical treatment or intervention should not be deferred or delayed based solely on a high ORS.

The current study takes on “many of the shortcomings” of prior studies—such as a 2021 database analysis from a group in Boston, and a 2018 study from Chicago researchers—with a “simple and clinically useful score,” said Kevin X. Farley, MD, MS, and Jacob M. Wilson, MD, both of Emory University School of Medicine in Atlanta, in an invited commentary accompanying the study.

“Past studies specific to the association of preoperative opioid use with postoperative outcomes have defined opioid use binarily (i.e., opioid users or nonusers) or categorically by the number of opioid prescriptions received in the preoperative period… These qualitative measures lack granularity and fail to capture the severity, temporality, and quantity of prescription drug use. They also ignore the potential influence of the combination of multiple controlled medications,” they wrote.

Farley and Wilson explained that pre-op patient optimization (weight loss; smoking cessation) is an established concept in total joint arthroplasty, and ORS could be another patient prep tool, as patients with an ORS ≥300 should be informed that they have an increased risk profile.

However, Farley and Wilson cautioned that more “study will be needed to determine whether an elevated ORS represents a modifiable risk factor, and until that time, no definitive clinical recommendations can be made,” but noted that “some limited evidence has suggested that opioid cessation prior to TKA may be associated with improved outcomes.” The American Academy of Orthopedic Surgeons and the American Academy of Pain Medicine do offer guidance on opioid stewardship in orthopedic patients.

Piuzzi’s group explained that “a significant association between preoperative substance use and post-TKA adverse outcomes.” particularly for pre-op use of opioids, stimulants, sedatives, or inhalants.” But a “high-risk designation threshold based on combined controlled substance use,” has yet to be established.

Their cohort study was done with data on a sample of 4,326 individuals (mean age 66.6; 60.63% women; 83.26% white; mean BMI 32.8 kg/m2) who underwent primary TKA from November 2018 through March 2020 at a tertiary care health system (six centers covering northeastern Ohio). Nearly 97% of the patients had a preop diagnosis of osteoarthritis. In terms of preop prescription drug use, 66% had a history of opioid while 66% had a history of sedatives use, and 3.4% used stimulants. Outcomes were assessed at 90 days postoperatively, and data were analyzed from September through October 2020.

NarxCare generates a 3-digit score from 0 to 999. The authors described the platform as “a reliable, routinely available, quantitative reflection of individuals’ overall consumption of prescription drugs that also accounts for prescription and dispensation patterns to assess patient-specific risk of use and overdose.”

The mean ORS was 117.9, with 33.3% of the patients in ORS 0 category and 24.6% in the ORS 1 through 99 category, the authors reported.

Piuzzi’s group reported that individuals in the highest ORS category had the highest ORs for:

  • Prolonged LOS: OR 3.71, 95% CI 2.00-6.87, P<0.001).
  • Non-home discharge: OR 4.09, 95% CI 2.02-8.29, P<0.001).
  • 90-day readmission: OR 4.41 (95% CI 2.23-8.71, P<0.001).
  • 90-day reoperation: OR 6.09 (95% CI 1.44-25.80, P=0.01).

However, an ORS ≥300 was not tied to procedure-related ED visits or 90-day reoperation, they noted.

Study limitations included that only a small number of patients had very high ORS and the fact that some readmissions and ED visits were not captured if they happened outside of the health system.

The authors pointed out that the overall readmission rates of 6.54% in their study were similar to those from the general Medicare population, and that their findings were in line with previous research, including a study that found no links between ORS and self-reported patient satisfaction with elective spinal surgery. Finally, they noted that ORS has been incorporated into many electronic health records systems so “such scores should prompt a surgeon-patient discussion and an interdisciplinary approach to mitigate deleterious prescription drug use patterns rather than being used as indicators for surgical ineligibility.”

  1. A preoperative overdose risk score (ORS) can be used to determine if patients eligible for total knee arthroplasty are at a statistically higher risk for prolonged hospital length of stay, nonhome discharge, all-cause 90-day readmission, and emergency department visits.

  2. Patients with a NarxCare ORS of ≥300 (scoring from 0 to 999), based on preoperative prescription drug use, had statistically significantly higher odds, but a high ORS is not a reason to defer surgical treatment or intervention.

Shalmali Pal, Contributing Writer, BreakingMED™

Piuzzi reported relationships with, and/or support from, the International Society for Cell and Gene Therapy, the Orthopaedic Research Society, the Journal of Hip Surgery, the Journal of Knee Surgery, RegenLab and Zimmer Biomet. Co-authors reported relationships with, and/or support from, The Journal of Arthroplasty, Stryker, the American Association of Hip and Knee Surgeons, and Zimmer Biomet.

Farley and Wilson reported no relationships relevant to the contents of this paper to disclose.

Cat ID: 438

Topic ID: 437,438,393,408,494,438,730,192,68,925,161