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The ** third step**
was to fit a main effects model (see Eq. 2) for each race and gender
group for each cause of death of interest---the results are given in
Tables III--V. Consider, as an example of how to read these tables,
diseases of the respiratory system (ICD 460--619) for white
males---see line 5 in Table III. Table AII (see first five
rows) shows the parameter estimates for each facility in log
percentage (L%) units in column 2 and the corresponding estimates of
the SMRs (adjusted for * S* and * L*) at the mid-point of the
1965--69 interval of follow up. These facility effect estimates
estimates are listed in columns 4 through 8 or row 5 in Table III.
The estimated relative risk (adjusted for * L* and * F*) for
monthly compared to nonmonthly workers is exp (-78.6/100) = 0.46 with
95% confidence interval of (.35, .59) indicating a substantial 5%
difference in respiratory system disease rates between monthly (white
collar) and nonmonthly (blue collar) workers. The estimated relative
risk (adjusted for * F* and * S*) for short term workers (**<** 1
year) relative to those who worked one year or longer is 1.30 with
95% CI = (1.17, 1.44). The period trend parameter estimate 0.97 (
see the last line of Table AII ) represents the yearly
change in the log SMR in L% units over the forty years of follow-up.
The parameter estimates for each cause of death in Tables III--V can
be combined to estimate the SMR for each facility, at the mid-point of
each follow-up interval for each level of * S* and * L*:
**
**

**
log (SMR) = log (facility SMR in 1965--69)
+ (effect due to *** L*)
+ (effect due to * S*)
+ (Interval-Midpoint--1967.5) * 0.97.

For example, for long term nonmonthly workers at K-25, during the last
interval of follow-up (1980-84), with mid-point = 1982.5, the log(SRM) is

log(SMR)= 6.7 + 0 + 0 + (1982.5-1967.5)*0.97 = 21.3L%

so that the estimated SMR is exp(0.213) = 1.24.

The lowest estimated SMR
was exp(-1.41)= 0.24 and occurs for:

X-10 Monthly Long-Term 1945--49
-43.0 + -78.6 + 0.0 + -19.4 = -141.0 L%.

The largest estimated SMR is 1.69 and occurs for:
K-25 Non-Monthly Short-Term 1980--84
6.7 + 0.0 + 26.1 + 14. = 47.4 L%.

The likelihood ratio statistic (see column 9 of Table III) for the null
hypothesis of no differences among facilities was 24.4 with 4 *
df* (* p***<**.01). Table AII indicates that the
risk of respiratory disease was much higher for TEC, K-25 and multiple
facility workers than for X-10 or Y-12 workers. For example, the
estimated relative risk for K-25 with X-10 as the reference facility
is exp[(6.7-(-4.0))/100] = 1.64. A large value for
the LRT statistic (in column 9 of Tables III--V) indicates that there
were differences among facilities in the death rates for that cause of
death after adjusting for * S*, * L*, period of follow-up, and
age through use of external rates.

** Next:** Dose-Response Analyses (DRA)
**Up:** Facility Comparison Analyses
** Previous:** FCP Step 2-

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