Reduced post-operative opioid use decreases length of stay and readmission rates in patients undergoing hip and knee joint arthroplasty

Abstract

Background: While adequate pain relief is central to patient recovery and satisfaction, opioid use is associated with side effects, adverse drug events and opioid use disorder and therefore is under increased scrutiny. Enhanced surgical recovery protocols include multimodal pain management as a key process, but the impact of opioid dose as an independent variable has not been examined.

Methods: Retrospective analysis of 51,824 hip and knee arthroplasty encounters in a large healthcare system.

Results: Overall, patients receiving treatment with lower doses of opiates had shorter median length of stay (p < 0.001); this earlier discharge had no negative consequences on readmission rates. In particular, patients discharged on day 1 received a lower median morphine milligram equivalent (MME) per day than those who were not discharged (32.5 [IQR: 19.0-50.0] versus 45.0 [26.7-71.2], respectively, p < 0.001). The probability of discharge on day 1 was 41.2% and 19.6% for those patients on lower versus higher MME/day, respectively. Similarly, there was a reduction in odds of readmission of 15.2% (95% CI 5.8-23.6%) for patients on lower doses of MME/day.

Conclusion: Lower MME/day following joint arthroplasty is linked to the probability of discharge on both days 1 and 2 post-surgery as well as reduced odds of readmission. These findings persisted even when adjusting for all other factors, including participation in the enhanced surgical recovery program, the use of a multi-modal analgesic regimen, the presence of complications, patient demographics, and other baseline characteristics. Efforts to reduce opioid use in the peri- and immediate post-operative period, regardless of the mechanism, demonstrated a significant effect on patient outcomes.

Keywords: Length of stay; Narcotics; Opioids; Re-admissions; Surgical recovery; Total hip arthroplasty; Total knee arthroplasty.

Graphical abstract

Fig. 1

Daily MME (median [IQR]) by discharge cohort. Cohorts represent total number of patients in the hospital and available for discharge each day. LOS≥1 day includes all patients. LOS≥2 days represents all patients not discharged on day 1. LOS≥3 represents all patients not discharged on day 2. Discharged patients are represented in the top section of each bar (green); patients who are not discharged (orange) make up the entire population eligible for discharge in the subsequent cohort. Within-cohort Wilcoxon rank sum test (p-values all < 0.001).

Fig. 2

Estimated probabilities of discharge by day for low and high observed MME per day. Estimated probabilities of discharge by day for low and high reference levels of MME/day (23.0 vs. 64.0, respectively).