Abstract
Introduction
The association between preoperative opioid use and adverse outcomes after total hip arthroplasty (THA) has been reported. However, a quantitative assessment used to evaluate the combined effect of controlled substance use and define a threshold for adverse outcomes after THA has not been established. The current study aimed to identify the association between the NarxCare Score (NCS) (indicative of controlled substance use) and length of stay (LOS), discharge disposition, 90-day emergency department (ED) visits, readmission, and reoperation after primary THA, necessary to identify a preoperative NCS threshold for adverse outcomes.
Methods
A total of 2,787 THAs (57.3% female; mean age: 64.3±11.14 years; NCS range: 0–800) were performed between November 2018-January 2020 at an integrated healthcare system with preoperative NCSs. Outcomes assessed included LOS, discharge disposition, 90-day ED visits, readmission (all-cause, procedure and non-procedure-related) and reoperation. The association between NCS category (in 100-point increments) and was analyzed through multivariate logistic regression accounting for risk factors.
Results
NCS of zero, 1–99 and 100–199 were similar regarding all investigated outcomes (p>0.05 for all). Compared to a NCS of zero, NCS of 300–399 was independently associated with higher odds of a LOS >2 days (odds ratio [OR]:2.27; 95% confidence interval [CI][1.59–3.24]; p<0.001), non-home discharge (OR: 2.0; 95% CI [1.34–2.99]; p=0.001), 90-day all-cause readmission (OR: 2.0; 95% CI [1.16–3.36]; p=0.012). Furthermore, NCS of 300–399 exhibited higher odds of a procedure-related readmission (OR: 3.74; 95% CI [1.48–8.13]; p=0.004). There were no differences between the NCS strata in 90-day reoperation and non-procedure related readmission rates (p>0.05 for each).
Conclusion
Higher NCS was associated with greater LOS and 90-day readmission, as well as lower odds of discharge to home. A NCS threshold of 300 can potentially designate high-risk patients for adverse outcomes after THA. This score may help stratify patients in the current alternative payment environment.
