Appendix B • Data and Analysis Methods
The Worker Health Chartbook 2004 is based on data collected from the surveys and surveillance programs described in Appendix A. The information used is largely in the public domain and is available from existing bulletins, reports, or government publications. The extensive use of electronic media and the World Wide Web have increased dissemination channels for government agencies, particularly where database management systems support customization of data queries from data users. At times, users overlook or are not sensitive to aspects of data collection, analysis methods, and dissemination practices that limit the uses and inferences of data. The following information is provided to assist the users of the Chartbook and reinforce the cautionary guides that accompany the dissemination of survey and surveillance data.
Census of Fatal Occupational Injuries (CFOI)
Census Measures
The Bureau of Labor Statistics (BLS) CFOI provides numeric and percentage distributions of its fatality totals for worker and case characteristics. Frequencies indicate the magnitude of a problem or the number of injuries that could be prevented. Worker and case characteristics used in the Chartbook include gender, age, race, and event or exposure.
Fatality Rates
Fatality counts from the BLS census are combined with annual average employment from the Current Population Survey [BLS 2003a] to produce a fatal work injury rate. Fatality rates depict the risk of incurring a deadly injury faced by all or a subgroup of workers, such as workers in a certain occupation or industry. The formula for calculating a fatality rate is
Fatality rate = (N/W) × 100,000
where N = the number of fatally injured workers aged 16 and older, and W = the number of employed workers aged 16 and older. Because neither hours nor employment is collected in the BLS census, fatality rates are calculated using annual average employment estimates from the Current Population Survey (CPS). Employment-based fatality rates measure the incidence of a fatal injury for all workers in the group regardless of exposure time.
Uses and Limitations
The CFOI helps safety and health experts to monitor the number and types of fatal work injuries over time and focus on work settings with particularly high risks. The CFOI database can produce fatality profiles for specific worker groups (self-employed or female workers, for example), certain types of machinery (such as farm equipment), and specific fatal circumstances (for instance, work activities at the time of fatal contact with electric current). Such profiles help identify existing work standards that may require revision and highlight safety problems for which intervention strategies need to be developed.
Although States are using independent data sources to identify and substantiate work-related fatalities, some fatal injuries at work are missed by the BLS census. Some unidentified work-related fatalities undoubtedly occur on farms, at sea, and on highways. States continue to search for new ways of verifying work-related fatalities to make their census counts as complete as possible. In that regard, States have up to 1 year to update their initial published counts with fatalities that were verified as work-related after data collection had ended for a given census. Since 1992, the average change due to updates in each year’s initially published total has been less than 1%.
Publication Guidelines
BLS considers data that could identify a person, company, or data source to be confidential and not for public release. Data that do not meet publication criteria are suppressed using dashes in tables and charts [BLS 2003b].
For further information, contact
U.S. Bureau of Labor Statistics
OCWC/OSH–Suite 3180
2 Massachusetts Avenue, NE
Washington, DC 20212–0001
Fatality information: 202–691–6175
Fax: 202–691–6196
Fatalities questions: cfoistaff@bls.gov
www.bls.gov/iif/oshcfoi1.htm
