Duration of initial opioid prescription strongest predictor of long-term use

The number of days’ supply of the initial opioid prescription was the leading factor in determining whether a patient is likely to continue opioid use long term, according to findings published in The Journal of Pain.

Other significant factors included opioid type and dose, according to the researchers. They advised clinicians to prescribe the minimum effective opioid supply and duration to lower unintended long-term use.

“In 2012, approximately 126 million U.S. adults suffered from pain, with nearly 50 million of them reporting chronic pain,” Anuj Shah, a PhD candidate from the division of pharmaceutical evaluation and policy at the University of Arkansas for Medical Sciences College of Pharmacy, and colleagues wrote. “Opioids are one of the most commonly prescribed drugs for alleviating or controlling pain, with almost 20% of the patients presenting in a physician’s office with non-cancer pain being prescribed an opioid. Insufficient evidence exists showing the benefits of chronic opioid therapy for pain management, but studies show greater risks of abuse, overdose and fracture with chronic opioid use.”

Shah and colleagues performed a cohort study to determine the associations between opioid prescription characteristics, pain etiology and the likelihood of opioid discontinuation. They used a nationally representative database that included health insurance claims data of commercially insured patients in the United States to identify 1,353,902 patients aged 14 years or older. Participants included those who had new opioid use episodes, but no history of cancer or substance abuse and were prescribed opioids for chronic pain, surgery trauma and other pain conditions. In addition, they used Cox proportional hazards models to determine causes correlated to time to opioid discontinuation.

Analysis accounting for losses to follow-up indicated that, across all participants, there was a 5.3% chance of continued opioid use at one year. Continued opioid use was most likely in patients with chronic pain and patients with inpatient admissions. A lower probability of discontinuation of opioids was observed in patients who were prescribed at least 90 morphine milligram equivalents (HR = .91; 95% CI, .91–.92) and initiated the medication with tramadol (HR = .89; 95% CI, .89–.90) or long-acting opioids (HR = .79; 95% CI, .77–.82).

“[People] with chronic pain compared to people who just had surgery are about 25% more likely to continue using opioids,” Bradley C. Martin, PharmD, PhD, co-author of the study, also from the division of pharmaceutical evaluation and policy at the University of Arkansas for Medical Sciences College of Pharmacy, said in a related press release. “Clearly, people with chronic pain are more likely to be long-term opioid users. The type of pain does matter, but before doing the study we thought chronic pain versus surgical pain would be a stronger predictor of long-term use.”

As days’ supply of the first prescription increased, the likelihood of opioid discontinuation decreased (HRs, CIs: 3–4 days’ supply = .70, .70–.71; 5–7 days’ supply = .48, .47–.48; 8–10 days’ supply = .37, .37–.38; 11–14 days’ supply = .32, .31–.33; 15–21 days’ supply = .29, .28–.29; 22 days supplied = .20, .19–.20).

“Compared to someone prescribed two days versus seven days, that person with a seven-day supply is twice as likely to be using opioids in the long term,” Martin said. “The days supplied is far more important than the dosage level or even the type of pain being treated.”

“Comparing someone who has a one or two-day supply of opioids with someone who has a week’s supply, the risk of use doubles,” he added. “This is something clinicians can easily modify when they prescribe opioids.”

This association was consistently seen among all pain etiologies examined.

The researchers also found most patients with an initial episode of opioid use were likely to discontinue use with more than 80% of chronic pain patients and 90% with non-chronic pain discontinuing in less than a year.

“This study shows that characteristics of the first opioid prescription, particularly duration of the prescription, are significant predictors of continued opioid use irrespective of the indication for an opioid prescription,” Shah and colleagues concluded.

“For this reason, clinicians should be particularly conscientious when initially prescribing opioids in ensuring that the days’ supply is no longer than necessary to mitigate the risk of unintentional long-term use,” they added. – by Alaina Tedesco

Disclosure s : The authors report no relevant financial disclosures.