title: Rates and risk factors for prolonged opioid use after major surgery: population based cohort study.
abstract: OBJECTIVE
  To describe rates and risk factors for prolonged postoperative use of opioids in patients who had not previously used opioids and undergoing major elective surgery.
  
  
  METHODS
  Population based retrospective cohort study.
  
  
  METHODS
  Acute care hospitals in Ontario, Canada, between 1 April 2003 and 31 March 2010.
  
  
  METHODS
  39,140 opioid naïve patients aged 66 years or older who had major elective surgery, including cardiac, intrathoracic, intra-abdominal, and pelvic procedures.
  
  
  METHODS
  Prolonged opioid use after discharge, as defined by ongoing outpatient prescriptions for opioids for more than 90 days after surgery.
  
  
  RESULTS
  Of the 39,140 patients in the entire cohort, 49.2% (n=19,256) were discharged from hospital with an opioid prescription, and 3.1% (n=1229) continued to receive opioids for more than 90 days after surgery. Following risk adjustment with multivariable logistic regression modelling, patient related factors associated with significantly higher risks of prolonged opioid use included younger age, lower household income, specific comorbidities (diabetes, heart failure, pulmonary disease), and use of specific drugs preoperatively (benzodiazepines, selective serotonin reuptake inhibitors, angiotensin converting enzyme inhibitors). The type of surgical procedure was also highly associated with prolonged opioid use. Compared with open radical prostatectomies, both open and minimally invasive thoracic procedures were associated with significantly higher risks (odds ratio 2.58, 95% confidence interval 2.03 to 3.28 and 1.95 1.36 to 2.78, respectively). Conversely, open and minimally invasive major gynaecological procedures were associated with significantly lower risks (0.73, 0.55 to 0.98 and 0.45, 0.33 to 0.62, respectively).
  
  
  CONCLUSIONS
  Approximately 3% of previously opioid naïve patients continued to use opioids for more than 90 days after major elective surgery. Specific patient and surgical characteristics were associated with the development of prolonged postoperative use of opioids. Our findings can help better inform understanding about the long term risks of opioid treatment for acute postoperative pain and define patient subgroups that warrant interventions to prevent progression to prolonged postoperative opioid use.
authors: Department of Anesthesia and Pain Management, Toronto General Hospital, 200 Elizabeth Street, Eaton North 3 EB 317, Toronto, ON, Canada, M5G 2C4.
authors: Hance
authors: H
authors: Clarke
authors: Neilesh
authors: N
authors: Soneji
authors: Dennis T
authors: DT
authors: Ko
authors: Lingsong
authors: L
authors: Yun
authors: Duminda N
authors: DN
authors: Wijeysundera
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D016001:Confidence Intervals; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016017:Odds Ratio; D009864:Ontario / Q000453:epidemiology; D009293:Opioid-Related Disorders / Q000453:epidemiology* / Q000209:etiology; D010149:Postoperative Pain / Q000188:drug therapy*; D011159:Population Surveillance; D011184:Postoperative Period; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013514:Surgical Procedures, Operative
chemical_list: D000701:Analgesics, Opioid