VIEWPOINT The Role of Preventive Dalmas

Medicine in Developing

A.R.

Dominicus,

and Takashi

Countries

Akamatsul)

Universityof Daressalaam,Schoolof Medicine,Tanzaniaand Departmentof PublicHealth,Schoolof Medicine, Universityof Kyorin,Tokyo), Japan (Received for publication on June 9, 1990)

Abstract.

In trying

to demonstrate

the importance

of preventive

medicine

in health

care

previous studies involving prevention and control of diseases have been discussed. Preventive also urged as the best method to help promoting health especially in the developing countries. countries

are urged

In terms

of cost analysis

to support

mortality

and/or

something

today in order

developing

prevention

morbidity,

countries,

materially

is an investment

therefore,

we,

investors

and financially

in health in the

that

in promoting

produce

developing

a reduced

countries,

promotion, medicine is Developed their

health.

probability

have

to gain a benefit at a later point in time. (Keio J Med 39 (4): 265-269,

of

to sacrifice December

1990)

Key words:

disease prevention,

cancer

screening,

infectious

Introduction

赤松

control

(application). Preventive medicine necessitates a systematic way of studying both the patterns of occurrence of disease in a community and the patterns of delivery of medical care, since offered services influence and also are influenced by the nature of disease and by the changes in modes of therapy. This systematic approach is provided by epi demiology, which forms the basic science of preventive medicine. It is understood that preventing illness and promoting health are functions of all medicine, therefore, preventive medicine represents a composite rather than a unitary body of knowledge. While in practice specific measures continue to occupy a central part in preventive medicine, general preventive measures have long been known to be very important. The successful application of both specific and general measures requires the effort of health education in order to achieve the cooperation of those people who comprise the community .3,4 There are two important objectives of preventive medicine; to prolong life, and to reduce disability. In the developed countries progress in achieving the first objec tive has been enormous due to social and economic changes that have resulted in better nutrition , smaller f amilies, better education, and the increase in medical knowledge that has enabled many diseases to be cured and prevented. It is at this point that we think developed countries, because of previous experience in solving

In the words of the noted medical historian, Henry Sigerist:1 Medicine, by promoting health and preventing illness, endeavors to keep individuals adjusted to their environment as useful and contented members of society, or by restoring health and rehabilitating the former patient it endeavors to readjust individuals to their environment. This idea conforms very well with the present concepts of preventive medicine (preventing ill ness and promoting health). In preventive medicine the community replaces the individual patient, as the primary focus of concern. In preventive medicine the objective is to evaluate the health of a defined community, including those members who would benefit but do not seek medical care. In this article, we intend to discuss the most important appli cations and cost effectiveness of preventive medicine in health promotion especiallyfor the interest of developing countries. Health problems in the developing countries are caused by many factors.2 That is, the majority of the people in these countries have low incomes, insufficient food, poor sanitation, poor access to safe water (treated tap water) and high population growth rate. We there fore strongly believe that the only way in which develop ing countries can effectively solve health problems facing them is through preventive medicine practice Reprint Uehara,

diseases

隆 requests to: Dr. Dalmas A.R. Dominicus Department Nishihara-cho, Nakagami-gun Okinawa 903-01, Japan

of Preventive

265

Medicine,

School

of Medicine

University

of the

Ryukyus

207

266

their

Dalmas

health

problems,

can help

a lot in improving

health

A .R. Dominicus,

et al.: Perspectives

of Preventive

Medicine

parties (administrators) who provide the investment capital are being sceptical of the idea of prevention as an investment for health care cost containment? There are several reasons. First, prevention is an investment which The Importance of Preventive Medicine first increases costs. Second, preventive measures usually in Disease Prevention cannot prevent morbidity and mortality from occurring, Economic aspect but what they can do is to postpone both morbidity and mortality. For example the studies of the consequences The main objective of economic analysis is not only to of reduced smoking by Leu and Schaub11show that life estimate the economic consequences of preeeeequences ofpreeeeeeeentive pro time health care expenditure of non-smokers are not less grammes (their costs and benefits) but also to contribute than those of smokers. However what we should all to an understanding of individual and collective choice in remember is the general lack of data about health care allocating resources to prevention. As a discipline econ expenditure over the life-time and we have also to remind omics deals with choices between alternative ways of ourselves, as Warner12 emphasizes, that postponding allocating resources. It is the characterization of the costs is also a means of containing costs. Third, and situation in which the decision has to be made that is perhaps most important, international and inter-regional most important, and the distinction between economic comparison shows that the level of health-care expendi and non-economic factors is secondary. The basic dis ture is not at all related to the health of the population.13 tinction between prevention and other health measures In the developing countries for example, health of the in terms of economic analysis is the timing of costs and people is still not satisfactory, but at the same time they benefits. From an economic point of view prevention is are the people getting the least in terms of health-care an investment that produces a reduced probability of expenditure. It is at this point that we feel that the mortality and or morbidity.5 The economic concept of developed countries through WHO or otherwise are to investment, means that the investor has to sacrifice assist the developing countries in promoting their health something today in order to gain a benefit at a later point status in terms of financial, material and manpower in time. Therefore for investment cost will always come support. before benefit in time. Costs are not only more immediate We think that it is hardly meaningful to try to general than benefits, but they are also more certain. It is always ize about empirical cost benefit, cost effectiveness and true that with investment we do not usually with certainity cost containment studies of preventive measures. For know what the benefit will be later in time. We can only example, if we take immunization programmes, you will receive the benefit with a certain probability. Now, when find those which produce benefit in excess of costs as well as those where the opposite is true. You will find screen in practice can we apply the economic theory of invest ment in preventive medicine? The economic theory of ing projects which are cost effective if they are applied to investment is obviously relevant for the analysis of one part of the population but not if they are extended to other groups. Some programmes are cost effective at one choices between alternative preventive programmes, be tween alternative designs of preventive programmes and point in time but not at later one. Mass screening for between the prevention and treatment of a particular tuberculosis might serve as the best example.9 Also there disease. This simply means that prevention and the will be some programmes for life style changes that economic concept of investment has to be developed reduce health care expenditures and others that increase with care. The aim of prevention is not primarily the them. An important point is to try to do the right thing at the right time and place. It is our personal believes that if monetary returns on invested capital and that the re sources spent on prevention are not only financial. The this is done correctly in the long run everybody will economic analysis of preventive measure as investments eventually benefit from a sound economic appraisal in therefore must include a careful assessment of costs and health care. benefits from a wider social perspective. Having this in mind we can use most of concepts, theories and methods Screeningfor genetic disease developed for the economic analysis of investment de Genetic diseases and congenital malformations are cisions for studies of the value of preventive medicine. 6-9 Preventive measures not only affect a person's health in important causes of neonatal and childhood diseases in the future (as understood generally) but could also affect the developed countries.14In many developing countries his or her future health care expenditure and future where single gene disorders occur at a particular high frequency as a result of natural selection, an even greater income in terms of production. The possibility of pre vention as a measure for containing health expenditure health burden will be caused by genetic diseases once the has been discussed in many previous studies.7,10What high mortality rates in early life due to malnutrition and are the reasons why some people especially the third infection are reduced .2,1The prevention of genetic dissituations

in the

developing

countries.

Keio J Med 39 (4): 265-269,

1990

267

eases prospectively (genetic counselling) entails screen ing large population for genetic diseases and then offering appropriate advice about marriage. Retrospectively, genetic counselling after the birth of an affected child has only a limited effect on the incidence of a genetic disease. Generally, programmes for preventing genetic diseases involve antenatal or neonatal screening for common dis eases. For instance antenatal screening is reserved for conditions which are either preventable, such as rhesus haemolytic disease, or are of such severity that there is an indication for termination of pregnancy, such as Down syndrome, neural tube defects, certain haemolytic dis orders and variety of rare metabolic disorders. Neonatal screening on the other hand is restricted to conditions for which there are useful treatments, such as hypothy roidism, phenylketonuria and sickle cell anaemia.16-18 Genetic screening is relatively expensive. However, it is very effective in reducing morbidity and mortality in the communities. Unless the gene probe technology is con siderably simplified and its cost reduced, this approach will not be widely applicable in rural population in the developing countries where rural infrastructures are still very poor.19This is the major challenge for the control of genetic diseases in the developing countries into which the developed countries must give a hand to its solution. Screening for cancer and coronary heart diseases The

ability

to identify

carcinoma

methods

led to the plausible

tion

treatment

and

vasive

cancer.

find cancers

signs

finding

them

20 The

cancers

more

cure.

Shapiro

from

under

by Baker.22

One

examination

a statistically

the colon

for

cancer

lung

is not

cytology.24,25

It has

enabling seems should given

rate

to be be

necessary

a very

of was trial

sigmoidoscopy in cancer trial

that

chest

of

involving

screening

for

x-ray

and sputum

that

endometrial

shown

in asymptomatic

cure

of

this

adults valuable

support

delivered reduce

control

rigid control

encouraged

a

breast

effectiveness

reduction

of

a

of

age of 50 years

indicates been

years

randomized

asymptomatic

also

that

and

using

makes

patient

noticed

can be detected

high

therefore countries,

also

and its precursors Screening

which

cancer effective

cancer.26

the

chance

The

Randomized

being

greater

the

significant

mortality.23

screening

women

cancer.

waited

history

and mammography under the age of 50

in women

digital

suggested

cancer

co-authors21

breast

also suggested

patient

giving

and

in is to

assumption

natural

to treatment

detec

prevent

screening

if the the

in their

of survival and

mammography involving

than and

early

might

of cancer

stage

earlier

examination to women

mortality

lung

purpose

amenable

probability

that

condition

or symptoms,

higher

physical annually

this

in an earlier

for overt that

of

in situ by cytological

suggestion

in and

particular for

health the

cancer activity

developing

assistance.

There is no dispute about the importance of hyper tension and ischaemic heart disease in the developed communities. Early attempts to study the impact of lowering diastolic pressure in the ranges of 90-114 mmHg and 115-129 mmHg were done by two Veterans Administration (VA) Cooperative Study Groups.27,28In these two studies the benefits were due to reduction in the frequency of stroke, heart failure, and renal failure. The results of the VA studies, coupled with those of other studies led to the more or less mandatory treatment of those with sustained diastolic pressure of 115 mmHg or more.29 The main predictors of IHD (ischaemic heart disease) other than sex, and increase in age are hypertension, hypercholesterolaemia and ciga rrete smoking. One view emphasizes the need for a downward shift in the blood cholesterol level for the community as a whole.30This shift of course will depend on successful health education and dietary changes and not a question of screening. The other view is that evidence in favour of the community approach to the prevention of IHD by dietary means is not sufficiently strong and that intervention should be confined to those at a particular high risk.31 The Oslo trial showed a significant reduction in IHD events in the group en couraged to adopt diet rich in polyunsaturated fat and to stop smoking.32The study by Berwick and co-authors33 showed good cost-effectiveness in the questions of methods of preventing IHD by modifying cholesterol levels in children. Screening for cigarette smoking is very discouraging. The effects of increase in price and in detailed informations may not have been well empha sized. At the moment, although cigarette consumption is going down in some countries, worldwide consumption of cigarette is going up. Switching to pipe and cigars smoking, nasal snuffing, chewing and dipping tabacco is not a solution.34 For instance chewing and dipping of tabacco might cause more cases of oral cancer. Alcohol consumption is known to be increasing world-wide. At the same time it was noted earlier that alcohol related disabilities were increasing.35 Therefore alcohol related diseases seem imperative to be included in the spectrum of conditions over which prevention is to be vigorously attempted. Many measures have been suggested for screening for alcoholism.36However, questionaires have been reported to be better than biochemical tests at eliciting a true picture of alcohol consumption.37 The results of the controlled intervention trial (alcohol study) showed good results especially in the intervention group.38 Mortality was reduced by almost a half in the intervention group. There was also significantly fewer sick leave days and days in the hospital in the intervention than the control group (most important aspect of preven tion in the control of alcoholism and alcohol related diseases).

268

Dalmas

Immunization and infectious diseases control

13.

A. R. Dominicus,

Forty-first 2000:

Prevention of infectious diseases by vaccination has been one of the major triumphs of medicine (one of the major role played and still being played by preventive aspect of medicine). There have been many previous studies done on different vaccine: for poliomyelitis vaccine,39 for pertussis vaccine,40 for measles vaccine,41,42 for rubella vaccine,42,43 for mumps vaccine,44 and for influenza vaccine.45 These studies consider vaccines' benefits, risks and costs and conclude that these vaccines result in a net savings of morbidity, mortality and cost (money). Studies of the benefits, risks and cost aid in altering or setting health policy. The benefits of smallpox vaccine which helped to eradicate this serious disease with rarity of serious adverse re actions to vaccination,46 caused this procedure of immu nization to be considered of unquestioned value.47 The point of importance to note here is that almost all studies on immunization demonstrated that the benefits out weigh the risks and costs for many vaccines (eg polio, pertussis, measles, mumps, rubella), and their use pro vides a net saving to society. In order to promote health status in the developing countries where infectious dis eases are still the major causes of morbidity and mor ality,

preventive

health

services.

programmes Problems

should facing

be the

developing

priorities

at

1988,

3-157

Weatherall

DJ:

Provincial 15.

YW,

analysis

Kazazian

AK:

analysis Blood

S, Venet

include

malnutrition,

infectious

diseases

and

Baker

23.

24.

poor

sanitation.2 25. References

1. Singerist HE: Primitive and Archaic Medicine. In: A History of Medicine, Vol 1, Oxford University Press, New York, 1951, 3-50 2. Dominicus DAR, Todoriki H, Gunshin H, Akamatsu T: Present health situation in Tanzania. Nippon Koshuu Eisei Gakkai Zasshi (Jpn J Public health) 37: 118-125, 1990 (in Japanese) 3. Wilkinson GS, Mirand EA: An experiment in health education and cancer control. Public Health Rep 91: 218-222, 1976 4. Grover PL, Miller J: Guidelines for making health education work. Public Health Rep 91: 249-253, 1976 5. Mushkin SJ: Health as an investment. J Polit Econ 70: 129-157, 1962 6. Kristein M: Economic issues in prevention. Prev Med 6: 252-264, 1977 7. Drummond MF: Studies in economic appraisal. In: Health Care, Oxford University Press, Oxford, 1981, 32-45 8. Susser M: Prevention and cost containment. Bull NY Acad Med 56: 45-52, 1980 9. Fuchs VR: Time preference and health, an exploratory study. In: Economic Aspect of Health, University of Chicago Press, Chicago, 1982, 93-120 10. Logsdon DN, Rosen MA, Demak MM: The insure project on life cycle, preventive health services, cost containment issues. Inquiry 20: 121-126, 1983 11. Leu RT, Schaub T: Does smoking increase medical care expendi ture? Soc Sci Med 17: 1907-1914, 1983 12. Warner KE: The economic implication of preventive health care. Soc Sci Med 13C: 227-237, 1979

W,

year summary report. Dales LG, Friedman

26.

27.

28.

29. 30.

31. 32.

33.

34.

Breast

health

385-404, Levin

Vol

2,

In:

World

cell

anaemia

TA,

by

1978

Mahoney

MJ, linkage

endonuclease

inherited

Screening,

site.

metabolic Wald

NJ,

ed,

221-238

Health

policy

and

implemen

1989

Principles

Health

Strax

and

Papers

P, Venet

screening

22.

phasic

2000.

34,

practice World

of

screening

Health

Organiz

1968

years effect of 349-355, 1982 LH:

T:

YG:

Public

Vik

1984,

192-200,

Jungner In:

Geneva,

Shapiro

38:

Evalu

year

2: 910-913,

other

Neonatal

Akamatsu

J Med

Africa:

the

restriction

Oxford,

Nuffied

by amniocentesis,

and

and

Press,

DAR,

on

cancer

L, Roeser

breast

cancer

detection

CA GD,

checkups,

R:

Ten

demonstration

32: 194-225, Collen MF:

trial.

JNCI

69:

project,

1982 Evaluating

a controlled

to fourteen

mortality.

five

periodic J

Chronic

multi Dis

32:

1979 ML,

mortality

also

Antenatal

JMG,

Lancet CD,

polymorphic

Phenylketonuria

diseases.

ation,

multiple

for

by

of sickell

cells.

Boehm

year

1-241

of ƒÀ-thalassemia

University

Wilson

JA,

practice.

Situation,

1987,

fluid

GM:

Keio

Health

diagnosis

1980

Dominicus tation.

Phillip

In:

Oxford

21.

Antenal

all

the

Organization,

1-76

Office

for

World

926-930,

Komrower

for

A:

Diagnosis

using 56:

disorders.

20.

the

of amniotic

HH,

Ritchey

19.

on

Geneva,

Dozy

clinical 1982,

Regional health

to

Health

and

London,

Medicine

Alma-ata

World

genetic

for

Organization,

Kan DNA

18.

strategy

Report

Health

17.

new Trusts,

of Preventive

From

mid-point.

Organization

the

Seventh

16.

The

Health of

Assembly:

the

Hospitals

World ation

Health

Reflection

Geneva, 14.

in

countries

World

et al.: Perspectives

Tockman in males

MS, screened

examination,

a preliminary

82:

1982

138-146,

Frost by

chest

report.

JK,

Ball

X-ray Recent

WC: and

Lung

cytologic

Results

Cancer

cancer sputum Res

Muhm JR, Miller WE, Fortana RS, Sanderson DR, Uhlenhopp MA: Lung cancer detected during screening programme using four month chest radiographs. Radiology 148: 609-615, 1983 Vuopala S, Kaupila A, Mikkonen M, Stenbeck F: Screening of asymptomatic postmenopausal women for gynecological malig nancies with special reference to endometrial sampling methods. Arch Gynecol 231: 119-127, 1982 Veterans Administration Cooperative Study Group: Effects of treatment on morbidity in hypertension. I. Results in patients with diastolic blood pressure averaging 115 through 129 mmHg. JAMA 203: 1028-1034, 1967 Veterans Administration Cooperative Study Group: Effects of treatment on morbidity in hypertension. II. Results in patients with diastolic blood pressure averaging 90 through 114 mmHg. JAMA 213: 114-1152, 1970 Management Committee: The Australian therapeutic trial in mild hypertension. Lancet is 1261-1267, 1980 World Health Organization Expert Committee: Prevention of coronary heart disease. World Health Organization Technical Rep Ser 678, 1982, 5-53 Oliver MF: Should we not forget about mass control of coronary risk factors? Lancet 2: 37-38, 1983 Hjermann 1, Byre KV, Holme I, Leren P: Effect of diety and smoking intervention on the incidence of coronary heart disease. Report from the Oslo Study Group of a randomised trial in healthy men. Lancet 2: 1303-1310, 1981 Berwick DM, Cretin S. Keeler E: Cholesterol, children, and heart disease: An analysis of alternatives. Oxford University Press, Oxford, 1980, 3-112 Winn DM, Blot WJ, Shy CM, Pickle LM, Toledo A, Fraumeni JF: Snuff-dipping and oral cancer among women in the Southern

Keio J Med 39 (4): 265-269, 1990

35. 36. 37.

38.

39. 40.

United Moser

States. N Engl J Med 304: 745-749, 1981 J: Prevention of alcohol-related problems;

269

developing

broad-spectrum programme. Br J Addict 74: 133-140, 1979 Lieber CS: A public health strategy against alcoholism and complications. Am J Med 65: 722-726, 1978

measles and rubella ence on Conquest

a its 43.

Bernadt MW, Mumford J, Taylor C, Smith B, Murray RM: Comparison of questionaire and laboratory tests in the detection of excessive drinking and alcoholism. Lancet 1: 325-328, 1982

44.

immunization. In: Proceeding of the Confer of Two Agents that Endanger the Brain:

Measles and Rubella, Gruenberg EM, ed, Oxford University Press, London and New York, 1984, 56-63 Schoenbaun SC, Hyde JN, Bartoshesky L, Crampton K: Benefit cost analysis of mumps rubella vaccination policy. N Engl J Med 294: 306-310, 1976 Koplan JP, Preblund

SR:

A

benefit-cost

analysis

of

mumps

Kristenson H, Ohlin H, Hulten-Nosslin MB, Trell E, Hood B: Identification and intervention of heavy drinking in middle aged men, results and follow up of 24-60 months of long term study

45.

vaccine. Am J Dis Child 136: 362-364, 1982 Klarman HE, Gozick D: Economics of influenza. In: Influenza Virus Vaccines and Strategy, Selby P, ed, Academic Press, New

with randomized controls. Clin Exp Res 7: 203-309, 1983 Weisbrod BA: Costs and benefits of medical research, a case study of poliomyelites. J Polit Econ 79: 527-544, 1971

46.

York, 1976, 255-270 Lane JM, Ruben FL, Abrutyn E, Millar JD: Death attributable to smallpox vaccination, 1959 to 1966 and 1968. JAMA 212:

41.

Koplan JP, Schoenbaum SC, Weinstein MC, Fraser D W: Pertussis vaccine, an analysis of benefits, risks, and costs. N Engl J Med 301: 906-911, 1979 Albritton RB: Cost-benefits of measles eradication. Effects of

42.

a federal intervention. Policy Analysis 4: 1-22, 1978 Koplan JP, White CC: An update on the benefits and

costs

of

47.

441-444, 1970 Fenner F, Henderson pox vaccine programme. Organization,

DA,

Arita

I, Jezek

Z, Ladnyi

ID:

Small

and vaccination in the intensified smallpox eradication In: Smallpox and Its Eradication, World Health Geneva, 1988, 539-592