Diarrhea-Related Ambulatory Health Care in the United States

Background Diarrhea is a common reason for seeking medical care. To characterize outpatient care for diarrhea in the United States, we analyzed data from the National Ambulatory Medical Care Survey (NAMCS) and the National Hospital Ambulatory Medical Care Survey (NHAMCS), administered annually by the National Center for Health Statistics. Methods The survey datasets contain information from a statistically representative sample of visits to ambulatory care providers, emergency departments (EDs), and hospital outpatient facilities in the United States. Datasets from 2007, 2008, and 2009 were combined to provide more robust estimates. Visits were defined as diarrhea-related if the code ‘15950' was found in any of three “reason for visit” fields. Following NAMCS guidelines, analyses were adjusted for the clustered survey design and weighted to produce national estimates. Results From 2007-2009, there were an estimated 38,868,949 diarrhea-related visits in the U.S., representing 1.1% of all estimated ambulatory care visits. Children <=4 years of age comprised 25.7% of diarrhea-related visits. Visits in this age group were also significantly more likely to be diarrhea-related compared to other age groups (OR=4.0, 95% CI 3.3-4.9). EDs cared for 23.0% of diarrhea-related visits; patients with diarrhea were more likely to be seen in EDs than patients with other concerns (OR=2.6, 95% CI 2.3-3.0). Conclusions In the U.S. from 2007-2009, a quarter of all ambulatory care visits for diarrhea occurred in infants and toddlers. This age group is known to high rates of illness from many enteric pathogens. A large proportion of ambulatory diarrhea-related visits occur in the emergency setting.