Current methods of estimating severity for occupational injuries and illnesses: data from the 1986 Michigan...

National and state estimates of the severity of occupational injuries and illnesses (severity = lost work time = missed work days+restricted work days) have come from the annual Survey of Occupational Injuries and Illnesses (Survey) produced by the U.S. Bureau of Labor Statistics. However, we show that the Survey practice of collecting injury information soon after the accident year reduces substantially the accuracy of missed work day estimates, which constitute 85.3% of the Survey lost work time estimate. To develop an independent estimate of missed work days, the research team created the Michigan Comprehensive Compensable Occupational Injury Database (Michigan Database) by linking state files with injury characteristics to files with workers' compensation information for injuries occurring in 1986. The measure of missed work time (days, weeks, or years) is the cumulative duration of compensation from the "date disability commenced," noted on the first payment form, through follow-up to March 1, 1990. Cumulative missed work time has been calculated or estimated for 72,057 injured workers, more than 97% of the 73,609 Michigan workers with compensable occupational injuries in 1986 identified through the close of the study. Our "best" estimate of missed work days, to follow-up, attributable to both fatal and nonfatal compensable occupational injuries and illnesses is 7,518,784, a figure four times that reported for Michigan by the Survey. When insurance industry data on disbursements are also considered, the estimate of missed work days increases to 8,919,079, a figure 4.75 times that reported by the Survey. When insurance data on reserves for future payments are also considered, the estimate of missed work days increases to 16,103,398, a figure 8.58-fold greater than that obtained for Michigan in the Survey. The Michigan data suggest that the national Survey may have failed to identify almost 373 million of 421 million missed work days in the private sector that have resulted, or will result, from 1986 occupational injuries. The present federal/state system for estimating occupational injury severity by measuring lost work days seriously underestimates the magnitude of the problem. The current policy of obtaining incidence and severity data from the same Survey should be reconsidered. We recommend that national estimates of injury severity be obtained from representative states by using state compensation data and that such estimates be used to evaluate current prevention and rehabilitation strategies. The redesigned occupational safety and health Survey (ROSH Survey) should be revised to permit linkage to compensation data.