North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) and the National Hospital Ambulatory Medical Care Survey (NHAMCS): comparison of emergency department data.

The North Carolina Disease Event Tracking and Epidemiologic Collection Tool (NC DETECT) is a near-real-time database of emergency department (ED) visits automatically extracted from hospital information system(s) in the state of North Carolina. The National Hospital Ambulatory Medical Care Survey (NHAMCS) is a retrospective probability sample survey of visits to U.S. hospital EDs. This report compares data from NC DETECT (2006) with NHAMCS (2005) ED visit data to determine if the two data sets are consistent. Proportions, rates, and confidence intervals (CIs) were calculated for ED visits by age and gender; arrival method and age; expected source of payment; disposition; hospital admissions; NHAMCS top 20 diagnosis groups and top five primary diagnoses by age group; International Classifications of Disease, 9th revision, Clinical Modification (ICD-9-CM) primary diagnosis codes; and cause of injury. North Carolina DETECT captured 79% of statewide ED visits. Twenty-eight persons for every 100 North Carolina residents visited a North Carolina ED that reports to NC DETECT at least once in 2006, compared to 20% nationally. Twenty-seven percent of ED visits in North Carolina had private insurance as the expected payment source, compared with 40% nationwide. The proportion of injury-related ED visits in North Carolina is 25%, compared to 36.4% nationally. Rates and proportions of disease groups are similar. Similarity of NC DETECT rates and proportions to NHAMCS provides support for the face and content validity of NC DETECT. The development of statewide near-real-time ED databases is an important step toward the collection, aggregation, and analysis of timely, population-based data by state, to better define the burden of illness and injury for vulnerable populations.