Opioid prescribing and utilization patterns in patients having elective hip and knee arthroplasty: association between prescription patterns and opioid consumption.

Purpose: Although guidelines can reduce postoperative opioid prescription, the problem of unused opioids persists. We assessed the pattern of opioid prescription and utilization after total hip arthroplasty (THA) and total knee arthroplasty (TKA). We hypothesized that opioid prescription patterns can influence opioid utilization.

Methods: With institutional ethics approval, patients undergoing THA and TKA were enrolled prospectively. Surveys on opioid use were completed at two, six, and 12 weeks after surgery. Patients' age, sex, American Society of Anesthesiologists' Physical Status score, first 24-hr opioid consumption, quantity of opioid prescribed, and quantity of opioid utilized were analyzed to evaluate their effect on opioid consumption, unused opioid, and patient satisfaction.

Results: Patients received prescriptions ranging from 200 morphine milligram equivalents (MME) to 800 MME. Three hundred and thirty THA and 230 TKA patients completed the surveys. Opioid utilization was influenced by the amount of prescribed opioids for both THA and TKA. The percentage of prescribed opioids used (~55% in THA and ~75% in TKA) and the proportion of patients using all prescribed opioids (~22% in THA and ~50% in TKA) were higher after TKA vs THA (P < 0.001 for both). Patients who used opioids for two days or less accounted for most (~50%) of the unused opioid. Patient satisfaction remained high and was not influenced by the amount of prescribed opioid.

Conclusion: This study showed that larger prescriptions are associated with higher opioid consumption. A wide variation in opioid consumption requires approaches to minimize the initial opioid prescription and to provide additional prescriptions for patients that require higher levels of analgesia.