Half of veterans prescribed medical opioids continue to use them chronically

Study subjects were drawn from national Veterans Healthcare Administration (VHA) data. Criteria for inclusion included at least 2 outpatient visits at a VHA facility in 2009 and at least 90 days of opioid use within a 180-day period. Opioid discontinuation was defined as no opioid use for at least 6 months. Funding for the study came from the National Institute on Drug Abuse.

Of 959,226 veterans who received an opioid prescription, 502,634 (representing 52.4% of the total sample) used opioids chronically.

The preliminary analysis showed that certain factors were more likely to be present in veterans who continued to use opioids chronically: They include post-traumatic stress disorder, tobacco use, being married, having multiple chronic pain conditions, the use of multiple opioids and opioid dose above 100 mg per day.

Some findings did not align with previous research in the fields of pain and addiction.

"Unlike other samples, it appears that mental-health disorders and substance-use disorders are associated with increased rates of discontinuation in the VA," said Mark Sullivan, MD, PhD, who led a collaborative team of researchers from the University of Washington in Seattle, Wash., the University of Arkansas Medical Sciences in Little Rock, Ark., and the Research Triangle Institute in Research Triangle Park, N.C. "The exception is tobacco use, which is associated with a decreased likelihood of discontinuation."

Dr. Sullivan emphasized that the veterans in the current study comprised the first sample where half of all opioid users were chronic users of greater than 90 days per year. Investigators examined demographic and clinical characteristics as well as treatment choices that could serve to predict opioid discontinuation. Pain characteristics and diagnoses related to medical conditions, mental health and substance abuse were included along with other medications, such as non-opioid pain relievers and those used to treat mental-health disorders.

Dr. Sullivan said lack of reliable or interpretable data precluded researchers from looking at pain levels as predictors of opioid discontinuation. Neither did the research team study the reasons why patients had received high doses of opioids.

Veterans are frequently prescribed opioids long term to treat painful conditions related to their military service. The current study built on past research from many of the same scientists showing that patients who misused opioids and who consumed high daily doses were among the least likely to discontinue opioids that had been prescribed on a chronic basis (Martin et al, J Gen Intern Med 2011; 26:1450-7). The previous study was not in veterans.

The practice of prescribing opioids long term for pain is controversial amid reports of increasing addiction and deaths related to medical prescribing and illegal diversion of the medications. Thus, the scientific field has renewed interest in ascertaining how medical use in veterans and in the general population relates to the prevalence of opioid-use disorders. Research has been sparse; however, a systematic Cochrane review containing 26 studies totaling 4,893 patients receiving long-term opioid therapy showed many patients discontinue opioids due to nausea and other adverse events, but that those who can remain on opioids experience pain relief with few serious problems, including addiction.