Prescribing Patterns for Outpatient Treatment of Constipation, Irritable Bowel Syndrome-Related Constipation, and Opioid-Induced Constipation: A Retrospective Cross-Sectional Study

BACKGROUND: Despite national recommendations for treatment of constipation, prescribing patterns for treatment are inconsistent, and health care utilization has increased. OBJECTIVE: To identify patterns in pharmacologic and nonpharmacologic treatment of constipation and associations between treatment and other variables across age groups. METHODS: This was a retrospective cross-sectional study that used the National Ambulatory Medical Care Survey (NAMCS) to compare prescribing from 2000 to 2004 and from 2005 to 2009. Treatment patterns for constipation, irritable bowel syndrome-related constipation (IBS-C), and opioid-induced constipation were considered. RESULTS: From 2000 to 2009, there were 89.6 million office visits related to constipation: 63.4 million for constipation alone, 28.2 million for IBS-C alone, and 3.7 million for opioid-induced constipation. For constipation, there was an overall decrease in the prescription of combination therapy (17% vs. 11%, P < 0.05); an increase in the prescription of medication monotherapy (21% vs. 29%, P < 0.05); decreases in the use of lubricants (9% vs. 2%, P < 0.05) and saline (7% vs. 1%, P < 0.001) among patients aged < 18 years; a decrease in combination therapy (31% vs. 17%, P < 0.05); and age group differences in the prescription of specific medications. For IBS-C and opioid-induced constipation, there were no changes in major treatment category or specific medication. Age, gender, race, ethnicity, payer source, physician specialty, and region were all found to be associated with treatment choice. CONCLUSIONS: Health care utilization for constipation increased, and prescribing patterns shifted significantly from 2000 to 2009 for constipation and IBS-C. Patterns in treatment were significantly influenced by many factors, including age, gender, and race. Changes in treatment categories over time included a decrease in combination therapy for patients aged < 18 years and an increase in medication monotherapy for all ages, which are in contrast to national recommendations.