1

he

Booze, C. F. Morbidity experience of air traffic
control personnei--i967-77, Aviat., Space,
Med, 50:1-8, 1979.

ornia Department Health Services. Hypertension
elated heaith problers in California: Results
the 1979 California hypertension sutvey August

Cali
rol

Cobb, S. and R.
and diabetes i
Assoc. 224(4):489

peptic ulcer,
5S. A Med

Freeman, D. H., D. A. D'Atri, K. Hellenbrand, et al.
The prevalence distribution of hypertension——
Connecticut adults, 1978-1979. J. Chronic Dis.
36(2):171-181, 1983.

Hypertension Detection and Follow-up Progran.
year findings of the hypertension detection anc
follow-up progran. Med. Assoc.

242(23)}:2562-2577, 1

Kannel, W. B., M. J. Schwarrz, aac P. M
Framinghar Study--Blood pressure anc Ti
heart disease. Dis. Chest 56(1):43-52,

MeNemara. The
x of coronary
1969,

Quinlan, C. 5. The epidemiology vpertension
Georgia. JS. Med. Assoc. Ga. 70(5):335~336, 1982.

103,

Poberts, J., et al.
of age, United States
11(222):1-107, 1982.



BLOOD PRESSURE LEVELS OF ACTIVE PILOTS COMPARED
WITH THOSE OF AIR TRAFFIC CONTROLLERS

INTRODUCTION

Hypertension and related complications represent a significant public
health problem in the United States today. Recent studies suggest that 18.1
percent of all Americans ages 18-74 years have definite hypertension, and
another 18.2 percent have borderline hypertension.

Currently some 15,212 active airmen are certified to fly with a diag-
nosis of hypertension. Federal Aviation Administration (FAA) blocd pressure
standards for certification of airmen are considered quite liberal, and recent
FAA policy with regard to allowable medications and dosages further liber-

alizes certification standards.

This study presents data pertaining to the prevalence of hypertension
by age group for all airmen, airline pilots, and a sample of active air
traffic control specialists (ATCS‘s) during 1980. Other pertinent comparisons
are made with large-scale population studies.

BACKGROUND

The Health and Nutrition Examination Survey (HANES) was designed to
assess the general health and nutritional status of the United States popula-
tion between the ages of 6 and 74 years (8). To achieve this goal, a proba-
bility sample of 24,513 persons representing the civilian, noninstitutional—
ized population was drawn by the United States Census Bureau. Nutritional and
health data collection began in April 1971 and concluded in June 1974. Data

were ccilecteé from 17,854 persons, an adjusted response rate of 74.4 percent.

The health examination included the indirect measurement of blood
pressure with a sphygmomanometer. Three measures of blood pressure were taken
with the subject in a seated position. Only the initial measurements, how-
ever, were used to calculate the prevalence of hypertension. Ninetv-eight
percent of the initial blood pressure measurements were taker by physicians.
Definite

ertension was defined as either a systolic biood pressure greater
than or equal te 160 mm Hg or a diastolic blooé pressure greater than or equal
to 95 mm Hg. Persons with a systolic blood pressure less than 160 mm hg and a
diastolic blood pressure less than 95 am Hg, but not both a systolic blood
pressure less than 140 mm Hg and a diastolic biood pressure less than 90 mm
Hg, were classified es borderline hypertensive.

Blood pressure was found in this cross-sectional study to increase
with age. Mean systolic blood pressure in males exceeded that of females
until age 55, at which time the mean systolic blood pressure of females became
greater. Mean diastolic blood pressure of males exceeded that of females
throughout life. Black males and females, 25-74 years oid, consistently had
higher mean systolic and diastolic blood pressures than their white
counterparts. Mean systolic and diastolic blood pressures varied inversely
with the population density of the area of residence, education, and family
income. Systolic blood pressure for males and females living in the souchern
United States, regardless of race, was found to be higher than that of persons
living in the northeastern or western United States.

1


Prevalence rates for ATCS's are consistently and wiformly higher than
for other airman categories studied. Earlier studies by Cobb aad Rose, and
Rose et al., found a higher prevalence of hypertension among controllers, pre-
sumably due to "job stress” experienced by ATCS's. Some speculation also
exists regarding the propensity of the typical ATCS personality type to higher
blood pressure.

Considerable interest has, of course, evolved recently concerning the
so-called stress of ATCS work in the wake of the August 1981 air traffic con-
troller strike.

Based on more liberal retention and waiver criteria for ATCS person~
nel, the higher overall prevalence findings among this group are to be ex—
pected. Certainly airline pilots and the all-airmen group are not relevant
comparisons with the combined overall prevalence data for ATCS's. The com—
bined overall prevalence rate of 21.1 percent for ATCS's is significantly less
than the combined rate of 36.4 for the general population, mainly due to a
lower prevalence of definite hypertension among ATCS's than among the general
population.

The most relevant comparison between airman and ATCS groups studied
and the HANES findings is with respect to the prevalence of borderline hyper-
tension. Again, airline pilots have a much lower prevalence rate than either
the all-airmen groups or ATCS's. However, rates for ali-airmen, ATCS's, and
the HANES population are more comparable; e.g., 14.8, 16.7, and 18.3 percent,
respectively. Significant differences at the 0.05 level are, however, ob-
served for the difference in rate between all-airmen and ATCS's, and all-—
airmen and HANES general population data. No significant difference in the
rates between ATCS’s and the HANES general population rate is observed. Age
adjustment does not affect conclusions based on crude rate analysis.

Prevalence of borderline and definite hypertension is seen to increase
with age for all groups studied, consistent with expectations. However, as
seen in Figure i, all groups increase at increasing rates with age, and the
highest increases are seeu for the ATCS group. It should be recognized, how-
ever, that the number of observations above age 60 among the ATCS group is
small. The potential for artifactual influence due to smail numbers should be
considered.


Several large regional studies concerned with hypertension and other
risk facters associated with coronary heart disease have provided estimates of
the prevalence of hypertension. One of the most well known is the prospective
study of the residents cf Framingham, Massachusetts. In 1949, 5,127 men and
women between the ages of 30 and 62 years who were free of any evidence of
coronary heart disease were entered into the study (6).

At entry into the study, three blood pressure measurements were taken
with the subject in a seated position by using a sphygmomanometer. Only the
initial measurement was used to characterize each subject's blood pressure
status. Definite hypertension was defined as a blood pressure greater than or
equal to 160/95. Persons with blood pressures ranging between 141/91 and
159/94 were considered borderline hypertensive. According to these defini-
tions, 16.98 percent of the Framingham study population were hypertensive, and
34.6 percent were considered to be borderline hypertensive.

Limitations exist in use of the prevalence data from the Framingham
population to make inferences to other populations. People with any evidence
of coronary heart disease were not entered in the study population. In addi-
tion, only individuals between the ages of 30 and 62 years at the time of
entry into the study were eligible.

In 1978 and i979, the first Connecticut blood pressure survey was con-
ducted to establish baseline prevalence rates of hypertension and the status
of blood pressure treatment and/or control (4). The target population of the
survey was Connecticut residents who were 18 years or older in 1978. A proba-
bility sample of Connecticut residents yielded 5,816 subjects, of whom 4,582
were interviewed and given blood pressure examinations.

Each subject was given a standardized questionnaire on hypertension
treatment status, nutrition and smoking. Three blood pressure measures were
taken during the interview by using the protocol of the Hypertension Detection
and Follow-up Program (5). Hypertension status was determined by using the
mean of the second and third readings. Definite hypertension was character-
ized as a systolic blood pressure greater than or equal to 160 mm Hg and/or a
diastolic blood pressure greater than or equal to 95 Hg, or a report of
current treatment with antihypertensive medications. Persons with a systolic
blood pressure between 140 and i59 mm Hg and a diastolic blood pressure less
than 90 m Hg or a systolic blood pressure less than 160 mm Hg and a diastolic
blood pressure between 90 and 94 mm Hg were termed borderline hypertensive.

The first Connecticut blood pressure survey found the overall preva-
lence of definite hypertension to be 14.02 percent and borderline hypertension
to be 17.43 percent.

During 1975 through 1977, 250,000 Georgians, 25 years or older, were
screened for hypertension (7). Hypertension was defined as a diastolic blood
pressure greater than or equal to 95 mm Hg or a diastolic blood pressure less
than 95 mm Hg, but current treatment with antihypertensive medications. Using
this definition, the investigators projected a prevalence rate of hypertension
for adult Georgians of 23.17 percent.


The overall prevalence of definite hypertension in adults, 18-74 years
old, was 18.1 per hund~ad persons. The age-adjusted prevalence rates of
definite Lypertensiun for whites and blacks were 16.8 percent and 30.5 per-
cent, respectively. Within the 18- to 74-year-old group, the prevalence of
borderline hypertension was 18.3 percent. Interestingly, the age-adjusted
prevalence of borderline hypertension was 18.5 percent for whites and 16.3
percent for blacks.

The initial Health and Nutrition Examination Survey was continued
through 1975 with the intent of further examination of the health status of
adults between the ages of 25 and 74 years (9). The probability sample con-
sisted of 9,881 adults between 25 and 74 years of age. Data were collected on
6,913, an adjusted response rate of 70.7 percent. In this phase of the study,
the three blood pressure measurements were averaged in an effort to account
for the often labile nature of blood pressure. The previously described cri-
teria for definite and borderline hypertension were used.

The findings of this portion of the HANES study were similar to those
using only the initial blood pressure measurement. The overall prevalence
rate in the 25- to 74-year-old group for definite hypertension was 18.0
percent. A prevalence rate of 17.1 percent was calculated for borderline
hypertension.

The Community Hypertension Evaluation Clinics were conducted at 1,171
sites in 42 states from 1973 through 1975 (11). During this pericd, over 1
million volunteers were screened for hypertension. Single blood pressure
measures, with the subjects in a seated position, were taken by trained volun~-
teers or health professionals. Subjects who were found to have a diastolic
blood pressure greater thar or equal to 90 mm Hg or a systolic blood pressure
greater than or equal to 180 mm Hg were referred to their family physician or
another appropriate source of health care.

Prevalence rates were calculated by using two definitions of hyper-
tension. The prevalence rate of hypertension defined as a diastolic blood
pressure greater than or equal to 90 mm Hg was 24.68 percent. A prevalence
rate of 11.56 percent was calculated by using a diastolic blood pressure
greater than or equal to 95 Hg as the definition of hypertension. The
all-volunteer study population may not be representative of the general popa-
lation, and, therefore, inferences should be made with caution.

The Hypertension Detection and Follow-up Progyam was a community-based
randomized clinical trial to assess the effectiveness of two forms of medical
care for hypertension (5,12). To ascertain study subjects, 14 target areas
were identified by using census tracts, A probability sample of 30- to
69-year-olds produced 178,009 subjects.

Between February 1973 and May 1974, 158,99 subjects completed the
first screening. During the initial screening, three blood pressure measure-
ments were taken with the subject seated by using a mercury sphygmomanometer.
Hypertension at the first screening was defined as a mean of the second and
third diastolic blood pressures in excess of 95 mm Hg. According to this
definition, 22,978 of the 158,906 persons measured were hypertensive, a preva~
lence rate of 14.5 percent.


Comparison of prevalence findings among the several studies publisned
in recent years, although fraught with problems due to differences in diag-
nostic criteria, age, sex, and race composition of the study, and size-
methodology consideration, still offers some clues to a better understanding
of the epidemiology of hypertension.

METHODS

Computer records maintained by the Aeromedical Certification Branch of
the Civil Aeromedical Institute were accessed to provide census data for ail
active airmen and airline pilots as of January 1, 1982. Since 1980, ATCS
health z:ords are no longer a part of the airman health data file unless the
controller is also a pilot; a 10-percent systematic sample of ATCS's active
during 1980 was selected from the airman health data file for the study (2,407
ATCS's). The Professional Air Traffic Controllers Organization (PATCO) strike
occurred in 1981, so this is a pre~strike saaple. Prevalence rates were
computed for borderline and definite hypertension according to the following
eriteria.

Definite hypertension was defined as either systolic pressure of 160
mm Hg or diastolic pressure of 95 mm Hg or more, or indication of medication
for blood pressure control.

Borderline hypertension was defined as systolic pressure below 160 mm
Hg and diastolic pressure below 95 mm Hg, but not both below 140 mm Hg sys-
tolic and 90 mm Hg diastolic.

Normotension is, therefore, both systolic pressure below 140 mm Hg and
diastolic pressure below 90 mm Hg. These criteria are the same as those
applied in the HANES and other studies.

The Guide for Aviation Medical Examiners specifies that blood pressure
should be taken with the applicant in the seated position.

RESULTS AND DISCUSSION

The overall prevalence of hypertension among airmen and ATCS's is
clearly less than results of other large~scale general population studies of
recent years (see Table I). Combined rates for borderline and definite hyper-
tension amounted to a prevalence rate of 16.8 percent for ali airmen, 10.6
percent for airline pilots, and 21.1 percent for air traffic controliers.
Similar general population prevalence from the 1971-74 HANES was 36.4 per~
cent. Prevalence of borderline hypertension for all airmen and the ATCS group
closely approximates the findings of HANES with prevalence rates of 14.8,
16.7, and 18.3 percent, respectively. As would be expected in a screened pop-
ulation, prevalence of definite hypertension is considerably less for all cat-
egories of airmen than for the general population. The airline pilot group
prevalence rates ate, of course, considerably less than those for all airmen
or ATCS's due to vigorous prescreening out of potential cardiovascular risks
by airlines, probably greater health consciousness among airline pilots, and
more rigorous FAA medical standards pertaining to airline pilots.


FAA-AM-84— 3

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Charles F. Booze, Jr.
Leslie S. Sincox*®

Civil Aeromedical Institute
Federal Aviation Administration
Oklahoma City, Oklahoza

*Department of Biostatistics and Epidemiology
University of Oklahona
Health Sciences Center
Oklahoma City, Oklahoma

April 1984

Document is available to the publi
National Technical Informati
Springfieid, Virginia

Prepared for
U.S. DEPARTMENT OF TRANSPORTA’ a
Federal Aviation Acministration
Office of Aviation Medicine
Washington, D.C. 20592

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SUMMARY

Prevalence of hypertension, either borderline, definite, or total, is
lower for airline pilots than For either the all-airmen group or the ATCS

group. It is higher for the general United States population than for eny of
the groups reported here.

Prevalence of hypertension is higher for the ATCS group than the ali-

airmen group, most likely due to more liberal waiver and retention eriteria
for ATCS's.

Prevalence of borderline hypertension is similar for the ATCS group
and the general United States population.



A survey was conducted in 1979 to estimate the baseline prevalence of
hypertension in adult residents of California (2). A multistage probability
sample of California households preduced a sample of 8,353 persons 18 years or
older. Interviews and blood pressure measures were completed on 7,774.

Three mezsurements of blood pressure were taken during the interview.
The mean of the second and third measures was used to determine hypertensive
status. A diastolic blood pressure greater than or equal to 90 mm Hg, a
systolic blood pressure greater than or equal to 140 mm Hg, or, regardless of
the blood pressure, a report of current use of antihypertensive medication
were three of the criteria by which hypertension was defined. These defini-
tions produced an overall prevalence rate of hypertension among California
adults of 24.0 percent.

Several earlier studies of the pievalence and incidence of hyper-
tension among pilets and air traffic controllers Save resulted in somewhat
mixed findings.

In a 1973 study of 4,325 air traffic controliers and 8,435 second
class airmen, Cobb and Rose concluded that the prevalence of diagnosed hyper-
tension was approximately four times higher among air traffic controliers than
among second class (presumably aviation-occupied) airmen (3). Data for this
study were obtained from automated records maintained by the Federal Aviation
Administration, and criteria for ascribing a diagnosis of hypertension were
systolic pressure greater than 140 mm Hg or diastolic pressure greater than 90
mm Hg as recorded on the most recent medical examination. Some licensing bias
was observed, since proportionally fewer active air traffic controllers than
second class airmen were denied medical approval. Rates for both groups were
considerably lower than emong the general population due to the screening
effect; i.e., all were previously certified airmen.

Booze studied the morbidity experience of 28,086 air traffic control-
lers from 1967 through 1977 and concluded that the prevalence of diagnosed
definite hypertension among controllers was lower than expected in comparison
with other large-scale prevalence study findings--either general population,
select geographic, or industry groups (1). While slightly more liberal cri~
teria were utilized in the FAA study, Booze further concluded that the apprex-
imately three times higher rates of definite hypertension observed in the
HANES and Framingham studies were not accounted for by criteria differences.

A 5-year clinical study conducted for the FAA under contract with the
Boston University School of Medicine concluded that the prevalence of hyper-
tension (both definite and borderline) among air traffic controllers was 1.5
times that of white males in the HANES study and that the prevalence of defi-
nite hypertension by HANES criteria was 1.6 times higher among air traffic
controllers than men in the general population (10). Comparison with the
Framingham study yielded a 1.5 times excess prevalence of definite hyper—
tension among air traffic controllers. Criteria for diagnosis of hypertension
in the Boston University study of ATCS's was either systolic greater than or
equal to 140 mm Hg or diastolic greater than or equal to 90 mm Hg on two suc-
cessive visits approximately 9 months apart.


Acknowledgment

Special thanks is extended to Dr. Elisa T. Lee, with the versity of
Oklahoma Health Sciences Center, for advice concerning the sample
design and to Mrs. Leslie Downey for her assistance in preparation of
this manuscript.



18.

REFERENCES

Booze, C. F. Morbidity experience of air traffic
control perscnnel--1967-77. Aviat., Space, Environ.
Med. 50:1-8, 1979.

California Department of Health Services. Hypertension
and related health problems in California: Results

from the 1979 California hypertension survey. August
1982.

Cobb, S. and R. M. Rose Hypertension, peptic ulcer,
and diabetes in air traffic controllers. J. Am. Med.
Assoc, 224(4):489-492, 1973.

Freeman, D. H., D. A. D'Atri, K. Hellenbrand, et al.
The prevalence distribution of hypertersiona——
Connecticut adults, 1978-1979. J. Chronic Dis.
36(2):171-181, 1983.

Hypertension Detection and Follow-up Program. Five
year findings of the hypertension detection and
follow-up program. J. - Med. Assoc.

242(23) 22562-2577, 197

Kannel, W. B., M. J. Schwartz, and P. M. McNamara. The
Framingham Study~-Blood pressure and risk of coronary
heart disease. Dis. Chest 56(1):43-52, 1969.

Quinlan, C. B. The epidemiology of hypertension in
Georgia. J. Med. Assoc. Ga. 70(5):335-336, 1981.

Roberts, J., and K. Maurer. Blood pressure levels of
persons 6-74 years. United States 1971-1974, Vital
Health Stat. 11(203):1-103, 1977.

Poberts, J., et al. Hypertension in adults 25-74 years
of age, United States 1971-1975. Vital Health Stat.
11(221):1-107, 1981.

Rose, 2. M., C. D. Jenkins, and M. 4S. Hurst. Air
traffic controller health change study. FAA Office of
Aviation Medicine Report No. FAA-AM-78-39, 1978.

Stamler, J., R. Stamler, W. F. Riedlinger, et ai.
Hypertension screening of 1 =: on Americans. J. An.

Med. Assoc. 235(21):2299-2306, 1976.

Wassertheii-Smoller, S., A. Apostolides, TM. ler, et
al. Recent status of detection, treatzent and control
of hypertension in the comaunity., J. Communit alth

5(2):82-92, 1979,



Technical Report Documentation Page

+ Booze, Jr., Ph.D., and Leslie S$. Sinco: ‘

Orgon-set on Nowe ons

Aeromedical Institute

ongoing Agency Neve one ©:
ifice of Aviation Medicine 1
deral Aviatio: istration
Oo Independence Avenue, S.z-

hashington, D. C. 20592 ;

2S Slopiementers Nowes

Te aeiese
currently some 15,212 active airmen are certified to fly with a diagnosis of hyper~ |
sion. Federal Aviation Administration blood pressure standards for certification |
airmen are considered to be quite liberal; however, recent FAA policy further
deralizeé medications and dosages allowed in certification of airmen.

information is available concerning the recorded blood pressures of
systematic sample of active pilots was extracted from automated medical
mtained by the Aeromedical Certification Branch of the Civil Aeromedical

itute descriptive purposes as well as to compare with a sample of air traffic!
contrellers, given the continuing terest in the relationship of stress of air traf-:
fic control work. This is a pre-strike ATCS sampie.

Distributions of blood pressure dy age were compared by using conventional non-
parametric techniques for 10-year age intervals. Data were also compared with gen-
erai population findings. Prevalence of hypertension is greater in the general
United States population than found with any of the groups reported here.

Prevalence of borderline and definite hypertension is seen to increase with age

for all groups studied. Prevalence of any degree of hypertension is lower for air-
line pilots than either the all-airmen group or the air traffic controller group.

Of the ree airman groups, prevalence of hypertension is highest for the air traffic)
controllers, but the influence of more liberal waiver and retention criteria for air

traffic controllers is an important reason for the excess. -. | ~

TF. Key Sores "18, Destrbution Stetement
: Hypertension, Prevalence, ° “Document is available to the public
} Active Pilots, ; through the National Technical
} Air Iraific Controllers i Information Service, Springfield, i
i ‘Virginia 22161. i
1 T9. Secunty Classif. cof “a report) 2. Security Classi. (of this page! [2E Se: oF Poses [22 Pace :
i j
i Unclassified Unclassified i
i

id {

Form DOT F 1709.7 (8-72) Reproduction of completed page authorized



NOTICE

This document is disseminated under the sponsorship of
the Department of Transportation in the interest of

information exchange. The United States Government assumes no

liability for itscontents or use thereof.



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