Risk factors for delayed opioid cessation following surgery

Prescription drug abuse is a growing problem. Little is known about factors leading to more persistent opioid use following acute injury. We proposed to use the peri-operative setting to identify psychological risk factors for prolonged opioid use. We conducted a prospective, longitudinal observational study among 77 patients undergoing either: (1) thoracotomy, (2) mastectomy, (3) lumpectomy, (4) total hip replacement, or (5) total knee replacement. Patients were recruited before their surgery and asked to complete a battery of questionnaires as a baseline assessment of various psychological and substance-abuse related factors previously implicated in opioid abuse. Factors included depression, anxiety, fear of pain, family and personal history of substance abuse, and self-perceived susceptibility to addiction, among others. Patients were then called daily post-operatively to record opioid use and Brief Pain Inventory (BPI) pain scores until the patient reached the endpoint of reporting both discontinuation of opioids and zero average pain for five consecutive days. Our primary endpoint for this study was time-to-opioid-cessation as defined by five consecutive days of zero opioid use. Cox proportional hazards regression of data from more than three thousand phone calls showed a median time to opioid cessation of 35 days (95% CI 23-40) Multivariate Cox regression analysis showed that pain duration (p = 0.001), depression (p = 0.002), and self-perceived addiction susceptibility (p = 0.025) were each independently and significantly associated with delayed opioid cessation. We have established that the surgical setting is ideal for establishing psychological factors that lead to more persistent opioid use following acute injury. These data may help improve understanding of how pain, psychological impairment and opioid use lead to chronic opioid use and abuse over time.