Descriptive evaluation of methods for identifying work-related emergency department injury visits

Background Use of worker's compensation (WC) as payer underestimates work-related (WR) injuries. We evaluated three methods to identify WR injuries: WC as payer, ICD-9-CM work-status codes E000.0/E000.1, and other ICD-9-CM external cause codes. Methods We identified injury-related emergency department visits from North Carolina's syndromic surveillance system (2010-2013). Characteristics were compared by indicator. We manually reviewed 800 admission notes to confirm if the visit was WR or non-WR; WR keywords from the review were applied to all visits. Results 133 156 injury-related visits (age, 16 years or older) were identified: WC = 69%, work-status codes = 18%, other ICD-9-CM codes = 13%. Among manually reviewed visits: few visits identified by WC (0.3%) or work-status codes (2%) were non-WR, while 12% of other ICD-9-CM code identified visits were non-WR; 53%, 46%, and 31% of visits identified by WC, work-status codes, and other ICD-9-CM codes were WR, respectively. Conclusions Findings support use of WC and work-status codes to capture WR injuries; other ICD-9-CM codes should be used with caution or in combination with other indicators.