The Health Examination Survey (HES) 1960-62 is based on an
examination of a representative sample of 6,672 persons drawn
from the civilian non-institutionalized population of the United
States, ages 18 to 79. The detailed component of the Health and
Nutrition Examination Survey (HANES), conducted between 1971 and
1975, is similar to the HES in that it is also representative
of non institutionalized persons in the United States (6,913 subjects
ages 25-74 were examined). Sample weights derived for these surveys
are used as appropriate. Both the HES and HANES involve clinical
examinations and follow very similar data collection procedures.
Our analyses are restricted to males who report current occupation
(approximately 17 per cent of the males in each sample are missing
occupation data) which results in final sample sizes of 2,409
(2,088 Whites) in the HES, and 2,424 (2,136 Whites) in the HANES.
In the HES data, the presence of myocardial infarction was judged
by a clinical panel of four doctors. Myocardial infarctions were
classified as definite (93 per cent) or suspect (7 per cent) based
on a review of the 12-lead electrocardiograms (EKG), chest X-rays,
medical history, and blood chemistry during analyses. The presently
available HANES data on coronary heart disease (CHD) are based
on the diagnosis made by the field examining physicians after
reviewing the medical history, the detailed cardiovascular questionnaire,
and the complete physical examination. (Chest X-ray and EKG tracings
may or may not have been available. An improved classification
based on expert EKG evaluation is still in process.) These criteria
have probably led to an underestimation of overall myocardial
infarction on the HANES. Experience with examining physicians'
initial diagnosis compared to final diagnosis with the HES shows
relatively few false positive CHD cases but a larger number of
false negatives. To reduce the unreliability due to misclassification
when angina is included, we decided to focus on that subset of
CHD which is most reliably assessed, myocardial infarctions (ICD
codes, 410-414). The number of cases in the HES is 39 (33 Whites)
and 30 in the HANES (28 Whites).