Chronic Opioid Therapy and Utilization of Emergency Departments

Chronic opioid therapy (COT) is an often-employed strategy for managing noncancer chronic pain. Along with the increase in COT for noncancer chronic pain has come an increase in reported opioid abuse and deaths from prescription opioid overdose, as well as an increase in visits to emergency departments (EDs) involving use of prescription opioids. The Centers for Disease Control and Prevention has estimated a 111% increase in the number of visits to the ED for nonmedical use of opioid analgesics from 2004 to 2008. Oxycodone, hydrocodone, and methadone were the most frequently noted; use of these agents has shown statistically significant increases over that time period. According to researchers, the association between opioid prescribing and adverse outcomes is not clear. The researchers recently conducted a study to investigate the relationship between COT prescription and subsequent ED utilization. They reported study results in Archives of Internal Medicine [2010;170(16):1425-1432]. The study data were gathered from administrative claim records from Arkansas Medicaid and HealthCore commercially insured enrollees. Inclusion criteria included age ≥18 years, continuous use of opioids for at least 90 days over a 6-month period between January 1, 2001, and December 31, 2004, and 12 months of continuous eligibility prior to and following the index date (index date was defined as the first full day of opioid use). Exclusion criteria included nursing home residents, hospice patients, and patients with a cancer diagnosis other than nonmelanoma skin cancer in the year prior to the index date. After applying inclusion and exclusion criteria, 38,491 enrollees from HealthCore and 10,159 from Medicaid were eligible for inclusion in the study analysis. Regression analysis was used to identify risk factors for visits to the ED and alcoholor drug-related encounters (ADEs) in the 12 months following ≥90 days of prescribed opioids. On average, those undergoing COT were middle-aged (mean, 50.4 in the HealthCore group and 52.9 in the Medicaid group) and predominantly female (59.2% in the HealthCore group and 71.7% in the Medicaid group). Of the HealthCore group, 55.1% (n=21,202) had been diagnosed with at least 1 noncancer tracer pain; of those in the Medicaid group, 74.4% (n=7555) had been diagnosed with at least 1 noncancer tracer pain. In both groups, the most prevalent diagnosis was back pain (36.8% [n=14,181] in the HealthCore group and 50.2% [n=5104] in the Medicaid group). In the HealthCore group, 24.2% (n=9297) had a visit to the ED in the 12 months following the index date of COT use; in the Medicaid group, 28.2% (n=2863) had an ED visit following the index date of COT use. In both groups, <3% had an ADE. In the HealthCore group, headache was the most common primary diagnosis for the first ED visit (10.0% of visits), followed by back problems (9.9%), abdominal pain (6.8%), sprains and strains (6.6%), and diseases of the heart (6.3%). In the Medicaid group, the most common primary diagnosis for the first ED visit was back problems (10.4% of the visits), diseases of the heart (7.7%), headache (5.3%), respiratory infections (5.3%), and sprains and strains (5.2%). In both groups, factors associated with more ED visits were younger age, female sex, more medical comorbidities, presence of back pain, presence of headaches, and greater number of nontracer pain conditions; in addition, alcohol, nonopioid drug use, and opioid abuse or dependence were strongly associated with ED use for both groups. In the HealthCore sample, the presence of mental health disorders was significantly associated with ED utilization; this was not the case in the Medicaid group. Mental health disorders were associated with ADEs in both groups. Opioid use per day was not associated with ED visits, but it doubled the risk of ADEs at morphine-equivalent doses >120 mg/day (the increase was statistically significant only in the HealthCore group; P<.001); use of short-acting Drug Enforcement Administration Schedule II opioids was associated with visits to the ED in both groups compared with use of non–Schedule II opioids alone. In conclusion, the researchers said that based on analysis results, among adults prescribed opioids for ≥90 days, “it may be possible to increase the safety of chronic opioid therapy by minimizing the prescription of Schedule II opioids in these higher-risk recipients.”