CFOI uses multiple data sources, including death certificates, workers' compensation reports, reports to various regulatory agencies, police reports, medical examiner records, and newspaper reports, to identify and verify work-related fatalities.
Beginning with data for 2008, CFOI applied a new rate methodology, changing the denominator from employment-based to hours-based. CFOI uses hours worked data from the Current Population Survey (CPS), a monthly household survey that collects data on the employment status of the civilian, non-institutionalized population aged 16 years and older. For the baseline year (2007), BLS produced both employment- and hours-based rates; the baseline estimate is for hours-based employment.
Hours-based rates are based on the average number of employees at work and the average hours each employee works. Hours-based rates measure fatal injury risk per standardized length of exposure, and are generally considered more accurate than employment-based rates. Employment and hours-based rates will be similar for groups of workers who tend to work full-time. However, differences will be observed for worker groups who tend to have a high percentage of part-time workers, such as younger workers.
Rates are expressed for full-time equivalent workers. Full-time equivalent employees equal the number of employees on full-time schedules plus the number of employees on part-time schedules converted to a full-time basis. The number of full-time equivalent employees in each industry is the product of the total number of employees and the ratio of average weekly hours per employee for all employees. An industry’s full-time equivalent employment will be less than the number of its employees on full- and part-time schedules, unless the industry has no part-time employees.
For consistency with the CPS data, workers under the age of 16, volunteers, and military personnel are excluded from the CFOI counts used to calculate rates. Information on the type of industry is converted to North American Industry Classification System (NAICS) codes.