FORECAST medical

From Big Medical Encyclopedia

FORECAST medical (Greek. prognosis) — anticipation of probable developing of a disease of a pla the prediction of character of a current and an outcome of the disease based on knowledge of patterns of development of pathological processes. The item, G. A. Zakharyin specified — «the assumption of the future which is based on the diagnosis: how the disease what to .zhdat changes at first, what in the following will go; what the disease — the recovery full or incomplete, or death will come to an end in; as the appointed treatment will work». P.'s creation, i.e. forecasting, represents a special type of cognitive activity of the doctor. A theoretical basis of forecasting is the prognostics — the science studying the general laws and methods of development of forecasts. The term «prognostics» is used in literature and in another, an enlarged sense, designating the theory and practice of forecasting in general.

Value P. is defined by the tasks connected with prevention (see), treatment (see. Therapy ) and rehabilitation of patients (see. Rehabilitation ). All medical and diagnostic and preventive activity of the doctor is penetrated by predictive assumptions and conclusions. The doctor needs to expect danger of a disease to health and life not only the patient, but also people around, the effect of treatment and probable complications of these or those to lay down. actions, a possibility of loss by the patient of working capacity in time to take measures for its preservation. Timely anticipation of complications of a disease (see. Complication ), side effects of medicines (see. Side effects of pharmaceuticals), development of palindromias under the influence of certain environmental factors (see. Recurrence ) is an indispensable condition of successful therapy and secondary prevention. Besides, compliance of the valid course of a disease predicted indirectly validates diagnosis (see). «The prediction is more correct, than it more is confirmed by further observation — G. A. Zakharyin said — the doctor is more self-assured, the less hesitates, the more resolutely acts, i.e. especially becomes the true practical figure, the practical doctor».

Attempts to define P. of diseases arose in an extreme antiquity along with emergence of doctoring since a prediction of an outcome of the disease (the person will recover or will die, will remain able-bodied or will be a disabled person) — the most important that interests the patient and persons close to it in judgments of the doctor. Besides its professional reputation considerably depended on ability of the doctor to predict disease. Therefore, according to V. of X. Vasilenko, forecasting arose in medicine before diagnosis or, to tell more precisely, during this period development of medicine when both the diagnosis, and treatment were exclusively symptomatic. Naturally, as P. during that time could be based only on the empirical accounting of visible symptoms which value for an outcome of diseases was estimated by doctors of antiquity sometimes with an amazing subtlety and depth (predictive value of the changes of outward of the patient known described by Hippocrates now as facies Hippocratica can be an example). Hippocrates's works (first of all his «Prognosticum») contain the whole set of rules of assessment of the predictive importance of symptoms of diseases, available to observation (position of the patient in a bed, expression of his face, coloring and temperature of an integument etc.). In the ancient time there were first representations (sometimes very naive) about risk to ache with this or that disease, about an opportunity to expect and prevent its development (ideas of infectious and noncontagious diseases, of transfer of a disease to the person animals, napr, rage, etc.).

With development of scientific medicine forecasting (see) began to lean more and more on diagnosis (see), in particular on definition of nosological accessory of a disease, its etiology and pathogeny, and also on the doctrine about individual and public hygiene. Did not lose, however, values and empirical elements P. - based on observation and medical experience (e.g., a prediction of critical temperature drop on 7 — 9 — the 11th day of a current of a lung fever, etc.). Considerable the contribution to the doctrine about P. was made by N. I. Pirogov, S. P. Botkin, G. A. Zakharyin, A. A. Ostroumov seeing guarantee of reliable medical forecasting in the achievements of medical science and socio-historical practice of doctoring refracted through a prism own a wedge, experience of the doctor. «Knowledge of the doctor, his experience and art cause big or smaller fidelity of a prediction» — S. P. Botkin wrote.

A methodological basis of modern scientific medical P. is the materialistic philosophy, the doctrine about dialectic development and unity of a material world, determinancy and basic cognoscibility of its phenomena, real existence of succession between the past, present and future. Being one of forms of scientific anticipation, the medical prognostics is based on the general principles of the Lenin theory of knowledge.

The problem of logical structure predictive (as well as diagnostic) thinking is developed still extremely insufficiently. In logical interpretation of the thought process which is the cornerstone of forecasting there are several directions. S. P. Botkin is the supporter of the hypothetical concept of the diagnosis — believed that «if the diagnosis of the patient represents more or less probable hypothesis, then the prediction following from this hypothesis will have a smaller degree of probability, than the first main hypothesis». However told by S. P. Botkin belongs to modern to it to the characteristic of the diagnosis and the forecast, immeasurably less reliable, more gipotetichny in comparison with present. A number of researchers, e.g. L. P. Dvornichenko (1977), considers that to logic of predictive conclusions more there corresponds the inductive or gipotetiko-inductive logical structure. Meanwhile does not raise doubts that, relying on high reliability of modern diagnosis and modern level of knowledge of patterns of development patol, processes, the doctor at P.'s creation does the conclusions, as a rule, going from the general to the particular, from the reason to the investigation. Therefore V. of X. Vasilenko believes that the decisive place in medical forecasting belongs to deductive logic. At the same time predictive conclusions are based on the basis of the correct uslovnokategorichesky or categorical syllogism.

In a wedge, four classes (type) of predictive tasks can be allocated to medicine:

1) forecasting of the state of health of healthy people in the conditions of impact on them of pathogenic factors, in particular in extreme situations;

2) forecasting of risk of a disease;

3) forecasting of disease; 4) forecasting of an outcome of the disease. Two last tasks are closely connected and usually are considered and solved in parallel practically in each case.

Forecast of a state zdorovI people and life activity of their organism in unusual conditions am necessary in cases when the healthy person has to be affected defined (sometimes extreme) factors, adaptation to the Crimea will demand from an organism of considerable efforts. Such P. is especially urgent, e.g., for air, space, sports medicine. Forecasting of influence on the person of such factors as zero gravity, high gravitation, a hypokinesia, an extreme exercise stress demands usually use of the special loading tests allowing to estimate a functional condition and adaptation opportunities of certain functional systems (cardiovascular system, a vestibular mechanism, the locomotory device, etc.).

Forecast of a possibility of a disease it is connected taking into account an etiology and a pathogeny of certain diseases, the influences of harmful household and production factors, specific features of the person (postponed earlier diseases, heredity, addictions, etc.). So, e.g., accommodation of the person at areas where the soil and water are characterized by an iodine deficiency, allows to expect development in it of a local craw. Existence at the immediate family on the fatherly and maternal line of a diabetes mellitus, and also the birth by the woman of the child of big weight allow to formulate idea of a prediabetes, i.e. the state threatening with a considerable share of probability to pass into latent or explicit diabetes. Predisposition to a nek-eye to diseases is estimated by detection of so-called risk factors. E.g., the risk of development of coronary heart disease increases at the burdened heredity, limited physical activity, arterial hypertension, obesity, smoking of tobacco, especially at men 40 years are aged more senior.

Such form of forecasting of a possibility of a disease as the medicogenetic consultation (more precisely, medicogenetic forecasting) allowing to define quantitatively risk of the birth of the child with this or that hereditary anomaly not only in patients but also in healthy families — so-called sporadic cases which inheritance in a family tree does not manage to be tracked (see was widely adopted. Medicogenetic consultation).

The item of possibility of a disease has special value for the Soviet health care directing the efforts first of all to prevention of diseases, including primary (see. Prevention primary ). The tool facilitating forecasting of an opportunity to ache with this or that disease in our country is first of all the local principle of the organization of medical aid (see. Medical site ), allowing the district doctor (see. district doctor ) it is good to know each inhabitant of the site, feature of its work and life, postponed in the past of a disease, i.e. all that gives an idea of possible predisposition to various pathology. To the same purposes serve the dispensary surveys covering the increasing contingents of the healthy population (see. Medical examination ). At last, the same problem in relation to occupational diseases is successfully solved by timely professional surveys (see. Medical examination). At the same time the persons inclined to respiratory diseases are not allowed to contact with production dust; the persons who had an acute viral hepatitis — to contact with hepatotoxic substances, etc.

Forecast of a current and outcome of a disease — type of medical forecasting, most widespread in applied medicine. Distinguish the forecast of a disease (the general forecast, the forecast of a nosological form) and the forecast of the patient (the individual forecast). The last is based on P. of a disease, but is under construction taking into account specific features of the patient (age, sometimes a floor, an individual immunoreactivity, etc.). Estimating value for individual P. of reactivity of the patient, a condition of its various functional systems, A. A. Ostroumov noted: «Only knowledge of features of an organism gives the grounds to expect such or other disease. On the contrary, the lack of knowledge of stability of bodies can mislead us when there is a complication of this or that body what we did not expect». The item shall answer a number of important issues: the disease will end with death and when or the patient lives (the forecast of preservation of life, or the vital forecast — prognosis quoad vitam) whether there will occur recovery (the forecast of recovery — prognosis quoad valitudinem), there will be a recovery full or the disease will accept a recurrent current whether working ability of the patient will be recovered (and in what degree) or he will be a disabled person (the social and labor forecast), the patient (the forecast of longevity — prognosis quoad longitudinem vitae what is the time will live).

According to the contents P. can be good (favorable — prognosis bona), doubtful (prognosis dubia), bad (adverse — prognosis mala), very bad (prognosis pessima) and foretelling a lethal outcome (prognosis lethalis).

The most important part P. — the forecast of preservation of life. From this point of view of V. of X. Vasilenko divides all diseases into four groups: 1) certainly incurable; 2) curable in early stages and incurable in late (e.g., malignant tumors during extensive innidiation); 3) the diseases which always are self-recovering or which are coming to an end with recovery after these or those medical actions; 4) all other diseases representing different degree of danger to life. In all cases of P. of an outcome and the course of a disease is defined by the following factors: reliability wedge. diagnosis, opportunities of modern therapy, specific features of an organism of the patient, conditions of the environment (including social).

Authentic diagnosis (see) — P.'s basis as nosological designation of a disease means disclosure, examination by the doctor of essence available for the patient pathological process (see). Definition of nosological accessory of a disease allows to build its general P., being based on the data of scientific medicine on the frequency of lethal outcomes at this disease, frequency and character of its complications, conditions of their emergence, reversibility of changes in various bodies, the reasons of a possible iivalidization etc. Often are defined by a nosological form the nature of disease (e.g., tendency to a recurrence at rheumatism, a peptic ulcer), possible complications (pustulous damage of skin, pyelonephritis at a diabetes mellitus, perforation of intestines, intestinal bleedings at nonspecific ulcer colitis etc.). The prediction at a certain disease shall consider features it etiologies (see) and pathogeny (see). So, the endocarditis caused by the green streptococcus can have the best P., than a fungal endocarditis; among various options of primary hyper aldosteronism of P. of efficiency of surgical treatment it is better at the isolated adenoma, than at a diffusion hyperplasia of bark of adrenal glands. Distinctions in morfol have a certain influence on P. options of the same disease (lymphoblastoid and miyeloblastny forms of an acute leukosis different morfol. forms of a chronic glomerulonephritis, carcinoma of the stomach etc.).

P.'s assessment at a certain nosological form is closely connected with modern opportunities of its therapy, and in this sense of P. is a concept concrete historical. For every period of development a wedge. medicine the idea of P. at this or that disease is characteristic. So, the bacterial endocarditis and tubercular meningitis which was considered before emergence of antibiotics as absolutely fatal diseases, nowadays, at timely diagnosis, recover in most cases. Creation of effective hypotensive drugs changed the general P. at such widespread disease as hypertensive. Thanks to achievements of surgery treatment of many forms of symptomatic arterial hypertension became possible, P. considerably improved at some heart diseases, hron. pulmonary suppurations, some types of vascular pathology, etc.

Progress of pharmacology and surgery allows more optimistically, than earlier, to estimate the next P. even of certainly fatal diseases. The artificial hemodialysis, transplantation of a kidney give the chance for years to prolong life to patients hron. renal failure. At a number of serious disabling diseases (a diabetes mellitus, a pseudorheumatism, hron. insufficiency of adrenal glands) vital and labor P. substantially depends on systematic performing medicamentous therapy, adequate treatment of complications (e.g., antiarrhytmic therapy at an acute myocardial infarction) or their prevention (e.g., reception of anticoagulants by patients with artificial valves of heart).

Individual P. is under construction taking into account a complex of factors, difficult and in different directions influencing body resistance of the patient to action of the disease-producing agent, a pathogeny of a disease, formation and formation of defense, adaptive, compensatory reactions. Except age and a sex of the patient, his constitution, extent of functional disturbances, a condition of compensatory systems, features of reaction to drugs, features of the personality and all knowledge of life, life, professional activity of the patient available to the doctor are considered. Anticipation of features of individual disease and its outcome is impossible without the correct assessment of degree of its weight. Disease severity is defined on the basis of a detailed research of a condition of the patient (consciousness, important functions — cardiovascular system, system of breath, function of a liver, kidneys, etc.). Predictively informatively emergence (or disappearance) separate symptoms. So, emergence of early extrasystoles like «R on T» at a myocardial infarction can foretell development of fibrillation of ventricles. Predictively an adverse sign is disappearance of rattles in lungs with development of a syndrome of «a mute lung» at the asthmatic status. To the contrary, a sign of improvement of a condition of the patient emergence of eosinophils in blood at a lung fever is considered, e.g.

Data on the diseases postponed earlier, side effect of the applied pharmaceuticals, about hron are important. diseases, to-rymi the patient suffers. So, existence at the sick inborn or acquired heart disease allows to expect development of an infectious endocarditis at emergence of certain symptoms. Anamnestic instructions on allergic complications from use of penicillin in the past exclude repeated purpose of this drug in order to avoid an acute anaphylaxis. At the persons suffering before from a peptic ulcer it is possible to expect its aggravation under the influence of reception of glucocorticoids or non-steroidal anti-inflammatory drugs.

The item of some diseases can be significantly burdened by existence of addictions to smoking (at hron. bronchitis, coronary heart disease), an alcohol abuse (at an infectious disease, hron. pancreatitis).

Personal features of the patient can significantly influence on individual P. Izvestno that persons hypochondriac, alarming, inclined to painful fixing of attention on the feelings, are ill always heavier, than people stenichny, balanced, capable to adequate assessment of the state.

Influence on P. of a disease of conditions of the environment is undoubted: climatic, household, professional. Also the social and economic conditions providing in our country to the patient the right for free medical aid, free receiving drugs at some hron are very significant. diseases (e.g., at a diabetes mellitus, a system lupus erythematosus, etc.). The item at a myocardial infarction, rheumatism considerably is improved by the multi-stage system of treatment and rehabilitation of patients realized in the USSR (a hospital — policlinic — specialized sanatorium).

Errors of the forecast for their reasons can be conditionally divided on objective and subjective. Sources of subjective mistakes are rather various: absence at the doctor of necessary experience in assessment predictively significant symptoms of a disease, logical mistakes, personal features of the doctor (unjustified pospesh a nost in conclusions, tendency to excessive predictive optimism or pessimism, etc.). Objective basis of mistakes is probabilistic character of P. as in relation to the separate, especially insufficiently studied nosological forms (objective difficulties of timely and reliable diagnosis of a disease, absence is unconditional reliable methods of treatment, etc.), and in relation to specific features of a current and an outcome (unexpected reactions to treatment, resistance to medicines, their intolerance; emergence of unpredictable complications of medicinal therapy or surgical intervention; development of the intercurrent diseases aggravating P. etc.). At wrong P. the objective and subjective reasons of mistakes are usually combined.

Deontological aspects of the forecast in each case of a disease are especially important at the choice of information about it of the patient and persons close to it (see the Deontology medical). The general principle of behavior of the doctor at discussion of questions P. — the maximum shchazheniye of mentality of the patient, suggestion to it beliefs in a happy end of a disease, relief of his sincere sufferings accompanying a disease. Under no circumstances it is impossible to speak to the patient about a possibility of a fatal outcome or to report the diagnosis of the disease which always is coming to an end with death (e.g., cancer). «For success of treatment — G. A. Zakharyin taught — the doctor shall encourage the patient, encourage recovery or at least, depending on a case, a correction of health, pointing to those good parties of a condition of the patient, which the last in the gloomy mood does not notice or does not appreciate».

It is not necessary to share with the patient with the doubts, difficulties in definition of the Item. Predictive reasons shall not be uncertain, ambiguous, indistinct since it guards the patient, inspires new alarms, undermines confidence to the doctor. At the same time assessment of an outcome of a disease shall not be and unreasonably encouraging, it is necessary to formulate it carefully. Promises of absolute and fast recovery (where it is impossible) are inadmissible, it is impossible to specify exact terms of disappearance of symptoms, burdensome for the patient (pain, fever, etc.), the possibility of improvement of health shall be put into dependence on the carried-out treatment, exact performance of medical appointments, etc. Patients (especially heavy hron, diseases) need to be accustomed to endurance, patience, they shall be psychologically prepared for «temporary deteriorations in health», exacerbations of a disease, sometimes for complications etc.

The doctor is obliged to report the truth about a condition of the patient to those from his immediate family who, in - per-vykh, has the moral right for such data and are for health reasons capable to transfer a sore news, and secondly, these sve-dettttya will not tell (accidentally or intentionally) to the patient.

The machine forecast of a current and outcome of the disease became possible in connection with creation of the COMPUTER intended for the purposes of diagnosis (see Diagnosis machine) and solutions of questions of medical forecasting. Specifically it found expression in creation of the special systems predicting an outcome of a disease (e.g., a myocardial infarction) on the basis of mathematical weighing of the predictive importance of the whole complex of its clinical and paraclinic signs. At the same time informational content of each sign (including the anamnestic data, a wedge, symptoms of a disease given tool and laboratory methods of a research) receives quantitative expression by means of attraction of rather difficult and various mathematical apparatus (mathematical models patol, states, the theory of recognition of images, the theory of accidental processes, methods of the discriminant analysis, a statistical sequential analysis of Wald, etc.). Early studies in this direction brought the encouraging results. However on the way of implementation of the specified methods to practice of medical forecasting there are considerable difficulties connected with impossibility of the strict quantitative description of the major a wedge, parameters patol, process, taking note for the outcome of a disease of individual reactivity of the patient, his mental features, various influences of the environment. In daily medical practice P.'s creation remains professional function of the doctor relying at the solution of this question on achievements modern a wedge, medicine and own experience.

See also Disease .

Bibliography: Bayevsky R. M. Forecasting of states on the verge of norm and pathology. M, 1979, bibliogr.; Botkin S. P. Clinical lectures, century 1, SPb., 1888; Hippocrates, the Chosen books, the lane with grechesk., M., 1936; D in about the district and h e N to about L. P. K to a question of methodological bases of the medical forecast, in book: Filosofsk. vopr. medical and biol., under the editorship of G. A. Rubtsov, century 9, page 113, Kiev, 1977; Yefimov I. N. The clinical and sotsialnr-labor forecast from a position of modern science about forecasting, Vestn. USSR Academy of Medical Sciences, No. 5, page 71, 1975, bibliogr.; Zakharyin G. A. Clinical lectures, century 1, M., 1895; Ostroumov A. A. Clinical lectures in 1881/82 academic year. m, 1882; Forecasting of efficiency of treatment, under the editorship of N. R. Ivanov, etc., Saratov, 1974.

V. K, Velikov, S. M. Kamenker.