Increasing frequency of opioid prescriptions for chronic abdominal pain in US outpatient clinics.

BACKGROUND & AIMS: Opioids are sometimes used to treat chronic abdominal pain. However, opioid analgesics have not been proven to be an effective treatment for chronic abdominal pain and have been associated with drug misuse, constipation, and worsening abdominal pain. We sought to estimate the national prescribing trends and factors associated with opioid prescribing for chronic abdominal pain.

METHODS: Chronic abdominal pain-related visits by adults to US outpatient clinics were identified using reason-for-visit codes from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey (1997-2008). Data were weighted to produce national estimates of opioid prescriptions over time. Logistic regression analyses, adjusted for complex survey design, were performed to identify factors associated with opioid use.

RESULTS: The number of outpatient visits for chronic abdominal pain consistently decreased over time from 14.8 million visits (95% confidence interval [CI], 11.6-18.0 visits) in 1997 through 1999 to 12.2 million visits (95% CI, 9.0-15.6 visits) or 1863 visits per 100,000 population in 2006 through 2008 (P for trend = 0.04). Conversely, the adjusted prevalence of visits for which an opioid was prescribed increased from 5.9% (95% CI, 3.5%-8.3%) in 1997 through 1999 to 12.2% (95% CI, 7.5%-17.0%) in 2006 through 2008 (P = 0.03 for trend). Opioid prescriptions were most common among patients aged 25 to 40 years old (odds ratio [OR] 4.6; 95% CI, 1.2-18.4). Opioid prescriptions were less common among uninsured (OR 0.1; 95% CI, 0.04-0.40) and African American (OR 0.3; 95% CI, 0.1-0.9) patients.

CONCLUSIONS: From 1997 to 2008 opioid prescriptions for chronic abdominal pain more than doubled. Further studies are needed to better understand the reasons for and consequences of this trend.