Opioid drug use in patients with chronic pain has been linked to psychological distress and substance abuse. Studies suggest that these factors are often more influential than the intensity of pain patients are experiencing. The determinants of the duration of opioid use after surgery have not been reported in previous research. Furthermore, few analyses have explored the factors that affect ongoing use of opioids after surgery.
In Anesthesiology & Analgesia, my colleagues and I had a study published that sought to determine preoperative factors that predict continued use of opioids long after surgery. Preoperative psychological distress and prior substance use was assessed in 109 patients who were undergoing various operations. After surgery, daily use of opioids was measured until patients reported ceasing use of these drugs and having no pain.
Three Important Factors
According to our results, three preoperative factors were independently related to long-term opioid use:
1. Legitimate prescribed opioid use.
2. Self-perceived risk of addiction.
3. Depressive symptoms.
Patients who were using opioids for pain relief before their procedure had a 73% higher likelihood of using these drugs at follow-up. Individuals who rated themselves at increased risk of developing an addiction were more likely to be long-term opioid users. The risk increased 53% for each 1-point increase on a 4-point scale of perceived addiction risk. Patients with symptoms of depression had a 42% higher risk for each 10-point increase on the Beck Depression Inventory scale.
The three factors identified in our study were significant regardless of the type of surgery patients underwent. These factors were also better predictors of long-term opioid drug use than the severity of pain or how long the pain lasted after patients underwent their procedure.
“Our findings are important because they raise concerns about a disconnect between the reasons these drugs are prescribed and non-pain related risk factors.”
When examined at 5 months after their operation, 6% of our study population reported that they were continuing to take the opioids they were prescribed. There would be 1.1 million new opioid users each year if this 6% rate was applied to the 17.6 million people who undergo these surgeries each year.
Our findings raise concerns about a disconnect between the reasons these drugs are prescribed and non-pain related risk factors that predict ongoing use. Surgeons, nurses, and other staff should make greater efforts to ask surgical patients before their surgery if they feel they may easily become addicted to these medications postoperatively. In addition, inquiring about previous opioid use as well as depression and anxiety may increase awareness of the potential for prolonged postoperative opioid use.
The three risk factors we identified may only be the beginning to learning about how and why patients are using opioids after surgery. More studies are needed to clarify the relationship between iatrogenic opioid exposure and risks of addiction. In the meantime, physicians should be proactive and inform patients about the risks of ongoing opioid use.
Readings & Resources (click to view)
Carroll I, Barelka P, Wang CKM, et al. A pilot cohort study of the determinants of longitudinal opioid use after surgery. Anesth Analg. 2012;115:694-702. Available at: http://www.anesthesia-analgesia.org/content/115/3/694.abstract.
Oderda G. Challenges in the management of acute postsurgical pain. Pharmacotherapy. 2012;32:6S-11S.
Alam A, Gomes T, Zheng H, Mamdani MM, Juurlink DN, Bell CM. Long-term analgesic use after low-risk surgery: a retrospective cohort study. Arch Intern Med. 2012;172:425-430.
Sinikallio S, Aalto T, Airaksinen O, Herno A, Kröger H, Viinamäki H. Depressive burden in the preoperative and early recovery phase predicts poorer surgery outcome among lumbar spinal stenosis patients: a one-year prospective follow-up study. Spine. 2009; 34:2573-2578.
Musclow SL, Bowers T, Vo H, Glube M, Nguyen T. Long-acting morphine following hip or knee replacement: a randomized, double-blind and placebo-controlled trial. Pain Res Manag. 2012; 17:83-88.
Van Den Kerkhof EG, Hopman WM, Goldstein DH, et al. Impact of perioperative pain intensity, pain qualities, and opioid use on chronic pain after surgery: a prospective cohort study. Reg Anesth Pain Med. 2012; 37:19-27.