Epidemiologic Investigation of Health Effects in Air Force Personnel ...

Table 6. RESULTS OF THE MATCHING PROCESS (1:10)
Cumulative
Age Difference (in Months) Number of Controls Cumu1 ative Percent
0 8612 70.6
1 10287 84.3
2 10749 88.1
3 10984 90.1
4 11167 91.6
5 11322 92.8
6 11410 93.5
12 11688 95.8
24 11921 97.7
36 12028 98.6
48 12129 99.4
60 12197 100.0
(5) Study Group Selection Procedures
(a)
Mo rta1i ty An a 1/s i s
A 50% random sample of each control set will be drawn and
used to comprise a 1:5 mortality analysis, as described in section (4). The
vital status of each subject in this sample and of all exposed subjects will
be ascertained at a minimum frequency of every five years for the 20 year
duration of the study. Those individuals dying of combat causes will be
excluded from the mortality analysis as it is assumed that combat death is
independent of herbicide effect. Further, the known differential combat death
rate between the RANCH HAND and control groups can be attributed to the
hazardous and unique nature of the RANCH HAND mission. Twenty-two RANCH HAND
personnel (15 officers and 7 enlisted) died in combat. Medical record reviews
will be accomplished to assess the illness experience of these individuals
prior to combat mortality.
(b)
Historical Morbidity Study
Retrospective or historical health data will be gathered on
each exposed subject and from the first randomly selected mortality control
from his set by questionnaire techniques. Living but noncompliant controls in
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