Beginning in October 2001, Massachusetts acute care hospital emergency departments (EDs) have been required to send summary electronic claims data about emergency department visits to the state Division of Health Care Finance and Policy. This study tests the use of these data for occupational health surveillance purposes. Data for a one-year period from October 1, 2001 through September 30, 2002 were analyzed to describe the extent and nature of ED visits made for treatment of work-related injuries and illnesses. Expected payment by workers' compensation insurance was used as an indicator of the work-relatedness of the patient's condition. Some of the major findings of the study include: 1) There were 93,082 ED visits for treatment of work-related conditions in Massachusetts from October 1, 2001 through September 30, 2002. These work-related ED visits accounted for 4.3 percent of all ED visits (2,202,357) during the study period, and 6.1 percent of ED visits (1,529,931) by persons of working age (16- 64 years of age). 2) There were about 3 work-related ED visits annually per 100 workers in the state. Based on comparison with estimates from other occupational health data sources, about 35% of work-related conditions were initially treated in EDs during the study period. 3) Almost three-fourths (71%) of visits for work-related conditions were made by male patients. The rate of work-related ED visits for males (3.9 ED visits per 100 workers) was over twice the rate for females (1.7 ED visits per 100 workers). 4) Rates of work-related ED visits were highest for workers under age 25 and declined with age. This trend was especially evident among males, with male workers age 20-24 having the highest work-related ED visit rate (6.5 ED visits per 100 workers), about five times the rate for male workers over age 64. The mean age of all patients treated in EDs for work-related conditions was 36.4 years. 5) About 15% of patients making work-related ED visits were Black or Hispanic, exceeding the proportion of those minority groups in the state's work force (9%). Patients making ED visits for work-related conditions were most likely to be White, male, and between 25-44 years old. 6) The vast majority (78.1%) of the work-related conditions treated in EDs were injuries and poisonings, followed by diseases of the musculoskeletal system (7.7%). The three most common types of work-related injuries were strains and sprains (22.5%), open wounds of the extremities (19.8%), and superficial contusions (17.2%). 7) Hospital ED charges for treatment of work-related conditions exceeded $45 million, with an average charge of $481 per visit. About four-fifths of the charges (81.4%) were for work-related injuries and poisonings, 8) Leading causes of work-related injuries and poisonings treated in EDs included being cut with a sharp object (21.0%), overexertion (19.1%), being struck by an object (16.6%), and falls (15.2%). 9) Almost 15% of all ED visits for injuries and poisonings for patients aged 16 to 64 years of age old involved work-related conditions. 10) Over half (54%) of all machinery-related injuries and 43% of all crushing injuries treated in EDs were related to work. 11) There were 2,286 ED visits made for treatment of work-related burns. Although most work-related burn victims were male, the majority of work-related burn injuries among workers under 20 years old involved females. 12) There were nearly 1,300 ED visits for work-related injuries and poisonings by teenagers 14-17 years of age. Close to half of these ED visits by teens (47.3%) were for open wounds. Burns accounted for 11.2% of work-related ED visits for injuries and poisonings by teens whereas they accounted for only 3.1% of workrelated ED visits for injuries and poisonings by workers of all ages. 13) The types of work-related injuries and poisonings treated in ED'fs varied by race and ethnicity. Black workers had a proportionately greater number of ED visits for work-related strains and sprains compared to other racial and ethnic groups, and a smaller proportion of open wounds and burns. Asian workers had a proportionately greater number of ED visits for burns and open wounds compared to other racial and ethnic groups. 14) Approximately 14.2% of all work-related ED visits were repeat visits by the same patient. Repeat visits are those made by the same patient for subsequent repeat treatment of a particular work-related condition. Of the 91,158 work-related ED visits included in this repeat visit analysis, 76,666 distinct patients were estimated to have made ED visits for 78,239 newly incident injuries and illnesses during the one-year study period. A number of data limitations should be considered in interpreting these study findings. The use of payment by Workers' Compensation as an indicator of work-relatedness likely underestimates the true extent of ED visits for work-related conditions. Some individuals injured or made ill at work, including the self-employed who comprise approximately 6% of the Massachusetts workforce, may not be not eligible for workers' compensation. Others who are eligible may not file workers' compensation claims. Also, while external cause of injury codes (E-codes) are generally accurate for broad cause of injury categories, they may be less accurate for the detailed causes of injury presented in this report for burn injuries. This exploratory study has demonstrated the potential usefulness of ED data as a supplement to other sources of information for occupational health surveillance in Massachusetts, particularly traumatic occupational injury surveillance. The ED data are readily available and contain information that has permitted us to characterize the occurrence, nature, and causes of work-related conditions in a way that complements what can be discerned from workers' compensation claims or estimates produced by the Bureau of Labor Statistics based on occupational illness and injury records maintained by employers. An important advantage of ED data for occupational health surveillance, compared to other available data sources, is that it captures information about all injuries, work-related and non-work-related. It therefore allows an assessment of the contribution of work-related injuries to the overall injury burden, fostering integrated approaches to prevention that cross public health disciplines (e.g. injury control and occupational health). While it is likely that not all ED visits for work-related conditions are identified using payment by workers' compensation as an indicator of work-relatedness, the outcomes of this study are sufficient to warrant periodic use of ED data as a supplement to other occupational health surveillance activities. Possible strategies for further enhancing the usefulness of ED data for occupational health surveillance include: universal recording and collection of information about the work-relatedness of patient's condition in the electronic database; entering information about the patient's activity at the time of injury; possible inclusion of a dedicated E-code field to capture location where injury took place; ensuring accurate "E-code" information about the external cause of injuries; expanding the collection and reporting of information about the patient's employer; and linking the ED data with workers' compensation claims data from the Massachusetts Department of Industrial Accidents.
Massachusetts Department of Public Health, Center for Health Information, Statistics, Research and Evaluation, Occupational Health Surveillance Program, 250 Washington Street, 6th Floor, Boston, MA 02108