Industrial Injury Hospitalizations Not Billed to Workers' Compensation: Characteristics, Trends, and Implications for Occupational Injury Surveillance

BACKGROUND: Occupational injuries place a heavy burden on workers, employers, workers’ compensation (WC) systems, and society as a whole. Under-reporting of work-related injuries and cost-shifting from WC to other health care coverage and/or to workers themselves is significant and potentially on the rise. There are critical occupational injury surveillance and research efforts that rely on the expected payer data fields in health care databases to identify work-relatedness—efforts that are hampered by the inability to identify all work-related injuries, and by the unknown degree of bias introduced by temporal trends in WC coverage. The objectives of this study were to describe characteristics of industrial injury hospitalizations by expected payer, and to test the hypothesis that industrial injuries were increasingly billed to non-WC payers over time.

METHODS: Industrial injuries were defined as presence of the external cause of injury place of occurrence code E849.3 (industrial place and premises) in any diagnosis field, which is a highly specific, albeit insensitive, payer-independent method. Place of occurrence codes (E849.X) have been used inconsistently across states and over time. This study used State Inpatient Databases (SID) from the Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, for the three states identified as having consistent usage of these codes (California, Colorado, New York). In addition to descriptive analyses by state, logistic regression models were used to estimate associations between age, gender, race/ethnicity, injury severity, and trends in expected payer (1998-2009).

RESULTS: There was a significant increase over time in the odds of an industrial injury not being billed to WC in California and Colorado, but a significant decrease in New York. These states had markedly different WC policy histories. Industrial injury hospitalizations for those ages 65+ had over three times the odds as other age categories of being billed to a non-WC payer (primarily Medicare).

CONCLUSIONS: This study adds to mounting evidence that, in at least some states, the relative burden on non-WC payers to cover health care for industrial injuries is growing, even while WC-related employer costs are decreasing. Findings suggest potentially dramatic cost-shifting from WC to Medicare. This study reinforces the importance of developing more comprehensive methods to identify work-related events in health care databases. In the meantime, place of occurrence codes are potentially useful for occupational injury surveillance and research efforts, and their use should be encouraged by policy-makers and data stewards within state health departments and hospital associations.