CF TB 08/08/96 Rate Technical Memo 1996

       1995 CENSUS OF FATAL OCCUPATIONAL INJURIES

              Experimental Fatality Rates

Both absolute numbers (or frequencies) and rates are 
useful when examining fatal work injuries for research or 
prevention efforts.  A frequency shows "how many" fatal 
work injuries occurred.  A rate indicates the relative 
danger.

The relative danger of an occupation or industry group 
can be indicated by combining frequency data with either 
employment or hours data to calculate a rate.  An hours-
based rate indicates the relative danger using time of 
exposure.  An employment-based rate indicates the 
relative danger using the number of employed workers.

Each type of rate has a different purpose.  An 
employment-based fatality rate measures the incidence of 
fatal injury for all workers in the group regardless of 
exposure time.  It does not account for the fact that 
part-time workers may have fewer fatal work injuries 
because they spend less time in the work environment.  An 
hours-based fatality rate accounts for different time of 
exposure levels among workers.  Hours-based measurements 
are especially useful for industry and occupation 
comparisons, when the number of workers can vary greatly 
among industry or occupation groups for a given period.

Work fatality counts from the Bureau of Labor Statistics 
(BLS) Census of Fatal Occupational Injuries (CFOI) can be 
combined with employment or hours at work data to produce 
a fatal work injury rate.  Since hours at work and 
employment data are not collected by CFOI, experimental 
fatality rates were calculated using estimates of 
employed1 civilian workers (age 16 and older) from the 
Current Population Survey (CPS).2  In addition, resident 
military figures, derived from resident and civilian 
population data from the Bureau of the Census, were added 
to the CPS employment figures to maintain consistency 
with the CFOI fatality data.

The fatality rates were calculated as follows.

                       (N / W) x 100,000

N = the number of fatally injured workers
W = the number of employed workers

The ratio N/W is multiplied by 100,000 so that worker 
groups with widely varying employment levels can be 
expressed in common terms (i.e., per 100,000 workers) for 
comparisons.

Example.  There were 6,210 total work fatalities in 1995.  
There were 126,248,000 employed workers (124,900,000 
employed civilian workers age 16 and older, and 1,348,000 
resident military personnel).

"N" must be adjusted to maintain consistency with "W," so 
the 26 fatally injured workers under age 16 are not 
included in the rate calculation.  (Adjustments of "N" 
are not reflected in the "Number" and "Percent" columns 
of the tables, which include all fatalities regardless of 
age.)

            N  =  6,210  -  26  =  6,184

                 W  =  126,248,000

      (6,184 / 126,248,000)  x  100,000  =  5

        5 fatalities per 100,000 workers

1  The rates do not reflect the movement of persons in 
and out of the labor force, the length of their work week 
or work year, or the effect of multiple jobholders.  BLS 
will continue its research on fatality rates using 
employment and exposure hours.
2  See "Explanatory Notes and Estimates of Error" in the 
January 1996 Employment and Earnings for an explanation 
of CPS sampling and estimation methodology, and standard 
error computations.  The relative standard errors of the 
CPS employment estimates can be used to approximate 
confidence ranges for the fatality rates.