64 - A prospective evaluation of clinical and psychologic factors on extended postoperative opioid use after primary total joint arthroplasty.

¹Kaiser Permanente, Irvine, CA, USA. ²Kaiser Permanente, Pasadena, CA, USA

Purpose
Anxiety, depression and pain catastrophizing have been implicated for increase in postoperative opioid use. The purpose of the study was to identify clinical and psychological risk factors associated with extended postoperative opioid use following primary joint replacement (TJR).
Methods
During preoperative visit patients were asked to fill out PHQ9, PCS (pain catastrophizing scale), opioid risk tool (ORT) and either KOOS-JR or HOOS-JR. Patient with opioid prescription dispensed after 90 days were considered as extended users. Enrollment was limited to primary TJR patients and data was collected in prospective fashion.
Logistic regressions were used for univariate and multivariable modellings and create receiver operating characteristic (ROC) curves. A backward stepwise regression analysis was used to select significant factors in the multivariable model.
Results
The study included 258 patients (163 TKR, 95 THR) with average age of 68.2 years (range 23 – 91), 58% (151) were females, average BMI of 30.21 (range 19.26 – 43.13), 49.22% were obese (BMI >30) and 19% had total PHQ-9 score > 10. The average length of stay was 1.41 days. 23.6% patients had associated back pain. 29.84% were on pre-operative opioids and the majority of which (81.78%) were taking opioids for reasons other than index primary joint pain.
14% (37 out of 258) of patients had opioids dispensed after 90 days (extended users). In univariate analysis, age < 65, associated back pain, chronic pain or fibromyalgia, previous use of opioids, drug potency of more than 10 morphine equivalent and total score on ORT of more than 7, were associated with extended use. In multivariable analysis, age < 65, associated back pain, chronic pain and preoperative use of opioids were significant risk factors for extended use (combine AUC = 0.83). Pre-op Opioid Use had the highest AUC=0.72 (p=0.0005). None of the psychological profile tests either as continuous variable of total score or accepted cut off predicted extended use.
Conclusions
In our prospective study, preoperative opioid use was the strongest predictor of extended opioid use after primary THR and TKR. Neither total nor accepted cut off scores of the psychological profile tests assessing depression, pain catastrophizing or opioid addiction risk corelated with extended use of opioids.