Trends in Healthcare Usage Attributable to Diarrhea, 1995-2004

Objective: To determine current diarrhea-associated healthcare usage rates and associated sociodemographic factors. These data can be used to determine the impact of the rotavirus vaccine. Study design: Using discharge diagnosis codes, we determined diarrhea-associated visit rates for children aged 0 to 18 years enrolled in Tennessee Medicaid, 1995-2004. Poisson regression compared data across time and within strata. The winter residual excess method estimated the rotavirus burden. Results: Analyzing approximately 500 000 person-years annually, outpatient and hospitalization rates remained stable from 1995 to 2004; emergency department (ED) rates approximately doubled, incidence rate ratio (IRR): 1.92 (1.81-2.04). White children used healthcare at greater rates than black children: outpatient IRR 1.90: (1.85-1.95), ED IRR: 1.69 (1.64-1.74), and inpatient IRR: 1.82 (1.73-1.92); and rural children greater than urban: outpatient IRR 1.66 (1.62-1.70), ED IRR 1.14 (1.11-1.17), inpatient IRR 1.88 (1.80-1.97). Children aged 0 to 35 months experienced 1627 outpatient and 792 ED visits, and 148 hospitalizations per 10 000 child-years; rotavirus may have affected up to 40% of these hospitalizations. Conclusions: Diarrhea-associated ED visit rates nearly doubled from 1995 to 2004. Future studies could explore factors resulting in increased healthcare usage by white children and those living in rural areas and document the rotavirus vaccine's impact after its release.