screening in medicine

From Big Medical Encyclopedia

SCREENING in medicine (English screening sifting) — the methodological approach used, in particular, in medicine for mass inspection of the population (its separate contingents) for the purpose of detection of a certain disease (group of diseases) or the factors promoting development of this disease (risk factors). With these purposes conduct skriniruyushchy examination, i.e. use a method of testing, with the help to-rogo make selection of the persons needing the corresponding medical intervention and also define prevalence of this or that disease and existence of the factors contributing to its emergence.

On the basis of results of skriniruyushchy inspection of inspected classify by existence at them of a disease and factors, to it contributing. So, in epidemiology and prevention of cardiovascular diseases of S. allows to classify the inspected contingent by such signs as smoking, consumption of alcohol, the ABP level, a ratio of separate forms of coronary heart disease in population. On the basis of assessment of separate risk factors and their combinations develop the tables characterizing a risk degree of emergence of new cases.

The main requirement during the carrying out skriniruyushchy inspection is existence according to the prepared personnel and standard approach to identification of the studied sign and assessment of the received results. The applied methods shall be rather simple, reliable and reproduced. It is necessary that they had sufficient sensitivity and high specificity.

The village assumes active mass inspection of the population irrespective of, the person asked for the help or not. Thanks to it vozkhmozhno more rakny and early detection of a disease or predisposition to it. Skri-niruyushchy inspections can have multi-stage character: the first stage — detection of a disease or the factors contributing to it; the second stage — more profound inspection for the purpose of specification of the diagnosis and making decision on necessary medical intervention. E.g., at the first stage reveal the frequency of occurrence of arterial hypertension, and on the second — in clinical or out-patient conditions specify the reasons of increase in the ABP; it allows to obtain data on the frequency of an idiopathic hypertensia and separate forms of symptomatic hypertensia.

Skriniruyushchy examination can be conducted among various groups organized (working at factories, the plants, in institutions, pupils of various educational institutions) and unorganized (at the place of residence) the population. In practice of health care it is applied at mass routine gynecologic maintenances, fluorography, recently S. gained considerable distribution in cardiology, oncology, pharmacology and medical genetics.

S.'s role becomes especially important at medical examination of the population (see. Medical examination ) and primary prevention (see. Prevention primary ). Due to the need examinations of the considerable contingents of the population by uniform standard criteria are conducted now by intensive searches of the automated and semi-automated methods C. Develop automatic machines and semiautomatic devices for measurement of the ABP, poll of the population, measurement of growth and weight (weight) of a body. The essential place is taken by development of the new, modern, reliable and public methods applicable for mass inspections, and also the reliable, possessing high capacity of the equipment.

Carrying out skriniruyushchy inspection sometimes is at a loss insufficient readiness of the population for it. Often it is connected with the fact that Individuals incorrectly estimate a condition of the health and are not ready to change lifestyle for the prevention of a disease, and also to be exposed to adequate treatment when the disease already developed. Special difficulties arise when repeated inspections are required. S.'s lack was so far that it was usually directed to identification not of group of diseases, and any one of them. Development of integral approach, i.e. detection of the basic noninfectious diseases, will allow to eliminate this defect considerably.

At S.'s carrying out it is necessary to consider its economic feasibility. In particular, falloff of incidence can lead to the termination or more rare carrying out skriniruyushchy inspection; tuberculosis detection of lungs can be such example.

Screening in medical genetics — one of methods of early detection of genetically caused diseases and separate syndromes (lag in growth, an albuminuria, a bacteriuria, - raised by the ABP, etc.). Detection of hereditary defects of a metabolism was the most productive. At early detection and treatment of such patients it is possible to prevent development of the diseases resulting usually in early disability and even by death. Skriniruyushchy inspection is widely applied in pediatrics since identification at children of various diseases and their early treatment often allow to exclude their manifestation at advanced age. So, S. of newborns on a fenilketonu-riya and the subsequent appointment of a diet as the patient with the low content of phenylalanine prevents development in them of mental retardation, a convulsive syndrome and other symptoms of a disease. In practice of health care of many countries use skriniruyushchy inspections among newborns on a fenilketonu-riya, a hypothyroidism, insufficiency alpha 1 - antitrypsin, a mucoviscidosis, a galactosemia. At identification of the patient it is inspected repeatedly, confirm the diagnosis, carry out specific treatment with regular biochemical control of its efficiency. Medicogenetic consultation is recommended to a family of the patient (see. Medicogenetic consultation ).

In populations with high frequency of this or that hereditary defect of a metabolism apply so-called prospective S. for the purpose of identification of heterozygous carriers of this defect, to-rye till the birth of the child get medicogenetic advice. With such defect at both parents that is real premises of emergence of the struck posterity, apply prenatal diagnosis. Skriniruyushchy inspection on a disease Teja — the Saxophone at Jews-ashkenazi or on a hemoglobinopathy at Italians, Blacks of the USA and Puerto-Ricans is an example of such programs. There are also selective S.'s programs concerning hereditary defects of a metabolism among the nek-ry contingents of patients with a high risk concerning accumulation of these defects. The selective S.'s programs for large pediatric clinics which are intended for detection of hereditary defects amino-acid, carbohydrate, lipidic, purine, pirimidinovy and nek-ry other types of exchange can be an example. Other example are selective S.'s programs for the contingent of mentally retarded, ophthalmologic, hematologic patients.

Unlike mass S.'s programs of the program of the selection S. do not bring direct benefit to the patient, but promote prevention of hereditary defects by medicogenetic consultation hereditarily of the burdened families. By means of these programs establish also a range of the hereditary defects of a metabolism widespread in population find existence of new defects of a metabolism.

Screening in cardiology, as a rule, carry out for the purpose of detection of the coronary heart disease (CHD) and risk factors of its development (smoking, disturbances of a lipidic range, low physical activity, existence of the arterial hypertension considered as an independent disease and as risk factor of an ischemic heart disease, etc.). Skriniruyushchy inspection in cardiology allows to classify inspected on existence and degree of manifestation of risk factors of an ischemic heart disease and arterial hypertension for the purpose of determination of necessary volume of actions for primary prevention of an ischemic heart disease. Classification of the ischemic heart diseases various forms and assessment of risk factors help to develop measures of secondary prevention. Skriniruyushchy inspection carries out the personnel which had special training on measurement of the ABP (viewing of the movie with records of tonometries and listening of tape recording, the analysis of indicators of the ABP at his simultaneous measurement by means of a multiphonendoscope), on filling of a standard questionnaire (questions on identification of an angina of exertion, existence of chronic pulmonary diseases, addictions — smoking, consumption of alcohol), on measurement of thickness of a skin fold, growth, weight, etc. Carry out also careful standardization of definition of biochemical indicators (a lipidic range, sugar of blood, etc.). Depending on the purposes skriniruyushchy inspection has single-step or step-by-step character. Repeated inspections allow to estimate stability of the studied indicators, napr, the ABP level, and to specify the diagnosis, and also to define dynamics of risk factors, incidences and mortality, to develop system of the preventive actions which are carried out by forces of scientific divisions and bodies of practical health care.

Screening in pharmacology consists in experimental identification pharmakol. activities of products of chemical synthesis and natural compounds. Distinguish several programs of skriniruyushchy inspection. During the work with essentially new ranks of chemical connections and in the absence of information about pharmakol. effect of substances carry out S. for identification pharmakol. activities of any kind by broad set of specific tests. By purposeful search of active agents carry out skriniruyushchy inspection using strictly certain set of tests for assessment of each class of substances, napr, tranquilizers, antidepressants, neuroleptics, anticonvulsant substances, etc. In some cases for identification pharmakol. actions of any one look use the so-called simplified skriniruyushchy inspection using one method; an example is use of the hypoglycemic test for definition of ability of substance to reduce concentration of sugar in blood. The used tests shall have high sensitivity and allow to separate quickly active connections from inactive.

Adequate tests in some cases allow to predict pharmakol. effect of substances on a human body. So, by a method of a conflict situation, napr, to antagonism with Corazolum, it is possible to predict anxiolytic effect of the tested drug, in the presence of kurarepo-dobny action in an experiment it is possible to assume the muscular action relaxing him on a human body, etc.

Purposeful skriniruyushchy inspection in pharmacology is very productive by search of new pharmaceuticals, especially in the ranks of analogs of the known drugs, during creation of new means by «imitation» natural biologically active compounds or by chemical modification of molecules of active connections. Modern methods (mathematical modeling, the multiple regression analysis of dependence of activity of connection from hydrophobic, electronic and steric factors, etc.) allow to analyze more deeply and thinly patterns of ratios between structure and fiziol. activity of chemical connections that promotes purposeful S.'s implementation in pharmacology.

See also Mathematical methods in medicine .

Bibliography: Anichkov S. V. Search of the central neurotropic means close to natural biologically active agents, Vestn. USSR Academy of Medical Sciences, No. 9, page 3,1976; And t of l and N of a JI. Page, It is suitable - W. E. der and Rozenblit A. B. Metod of selection of topological and topographical signs of biological activity of chemical compounds, Chemical - pharm. zhurn., t. 14, No. 7, page 48, 1980; Dmitriyev N. V., etc. Probabilistic model of screening, Izv. Academy of Sciences of the USSR, it is gray. biol., No. 4, page 520, 1979; Krasnopolsky K. D. Skrinirovaniye of hereditary diseases of exchange in population, in book: Lectures on medical genetics, under the editorship of A. A. Prokofieva-Belgovskaya and V. P. Efroimson, page 120, M., 1974; Martinson A. E. Identification of hereditary diseases of exchange in pediatric clinic, Pediatrics, No. 11, page 9, 1978; Mashkovsky M. D. Problems of pharmacological search and clinical trial of new medicines, Vestn. USSR Academy of Medical Sciences, N ° 10, page 52, 1968; it, Theoretical and practical bases of search of psychotropic drugs, in the same place, No. 9, page 14, 1976; North A. F. Screening in child health care, where are we now and where are we going? Pediatrics, v. 54, p. 631, 1974; S a-c k e t t D. L. Laboratory screening, Fed. Proc., v. 34, p. 2157, 1975, bibliogr.; Turner R. A. Screening methods in pharmacology, N. Y. — L., 1965; W e a t h e-r a 1 1 M. Chance and choice in the discovery of drugs, Proc. roy. Soc. Med., v. 65, p. 329, 1972.

A. A. Alexandrov; V. A. Bogoslovsky (cards.), T. A. Voronina (pharm.), K. D. Krasnogyulskaya (gen).