Concept of health and disease

Concept of health Biomedical concept

Absence of disease Has the basis in the germ theory of disease It has minimized the role of the environmental, social, psychological and

cultural determinants of health Inadequate to solve health problems like malnutrition, chronic diseases,

accidents, drug abuse, mental illness, environmental pollution, population explosion etc.

Ecological concept Health as a dynamic equilibrium between man and his environment, and

disease a maladjustment of the human organism to environment. Psychosocial concept

Health is influenced by social, psychological, cultural, economic and political factors of the people.

Holistic concept Health implies a sound mind, in a sound body, in a sound family, in sound

environment. All sectors of society have an effect on health.

Health

• Definition - Health is the state of complete physical, mental and social wellbeing and not merely an absence of disease or infirmity.

- WHO 1948Operational definition of health

Health can be seen as a condition or quality of human organism expressing the adequate functioning of the organism in a given conditions, genetic or environmental.

New philosophy of health• Health is a fundamental human right.• Health is the essence of productive life, and not the

result of ever increasing expenditure on medical care.• Health is inter-sectoral.• Health is integral part of development.• Health is the central to the concept of quality of life.• Health involves individuals, state and international

responsibility.• Health and its maintenance is a major social

investment• Health is worldwide social goal.

Dimensions of health

Physical dimensionMental dimensionSocial dimensionSpiritual dimensionEmotional dimensionVocational dimension

Dimension of health Physical dimension

state in which every cell and every organ is functioning at optimum capacity and in perfect harmony with the rest of the body.

Mental dimension Ability to respond to the many varied experiences of life with

flexibility and sense of purpose. Social dimension

Quality and quantity of an individuals interpersonal ties and the extent of involvement with the community.

Spiritual dimension Integrity, principles and ethics, the purpose in life, commitment

to some higher being.

Dimension of healthEmotional dimension

Emotional health relate to the feeling.Vocational dimension

Part of human existenceOther dimension

Philosophical dimensionCultural dimensionSocio-economical dimensionEnvironmental dimensionEducational dimension etc.

Positive health• Perfect functioning of the body and mind.• Positive health always remain the mirage,

because everything in our life is subject to change.

• Health described as a potentiality the ability of an individual or a social group to modify himself or itself continually, in the face of changing condition of life.

• Positive health depends not only on medical action, but on all the other economic, cultural and social factors operating in the community.

Spectrum of health

Positive healthBetter healthFreedom from sickness

Unrecognized sicknessMild sicknessSevere sicknessDeath

DETERMINANTS OF HEALTHBiological determinants

Behavioral & Socio-cultural conditions

Environmental/ Socio –economic conditions

Health services

Aging of population

Gender

Other factors

DETERMINANTS OF HEALTHBiological determinants

Physical, mental ,genetic make up

Behavioral & Socio-cultural conditions

lifestyle, cultural, behavior ,personal

habits & addiction(eg. smoking, alcohol) Environmental Socio –economic conditions

Internal

External

DETERMINANTS OF HEALTH

Social –economic conditions

economic status, education, occupation, political system

Health services

family welfare services,treatment of diseases

Prevention of illness, promotion of health

Immunization “Primary health care”

DETERMINANTS OF HEALTHAging of population

increases chronic diseases & disability

Gender

Nutrition , reproductive health , violence,

aging , lifestyle condition

Other factors

mass media, health related system(Food agriculture, education , industry, rural

development)

DETERMINANTS OF HEALTH

VHealth

Communities

SocietiesFamilies

Individuals

Biological

Human rights

Equity and social justice

Gender

Behavioural

Environmental

Socio-economic

Health system

Socio-cultural

Aging of the population

Science & technology

Information & communication

Health

Health care Indicators• Indicator ? variable which help to measure changes (WHO)

• How healthy is a given community?

• Indicators requires - to know health status of country - to compare health status with another

- to assess the health care need - for allocation of scarce resources - monitoring & evaluation of health

services, activities & programmes

Health Indicators Vs Health index(indice)

In relation Amalgamation of

to health trend health indicators

Characteristics of Indicators

Ideal indicator should be Valid

Reliable & objective Sensitive

Specific Feasible

Relevant

Classification on indicators1. Mortality indicators2. Morbidity indicators3. Disability rates4. Nutritional status indicators5. Health care delivery indicators6. Utilization rate 7. Indicators of social and mental health 8. Environmental indicators9. Socio-economic indicators10. Health policy indicators11. Indicators of quality of life12. Other indicators

Mortality indicator • Crude death rate• Expectation of life _ at birth• _ at age of 1• _ at age of 5• Infant mortality• Child mortality rate• Under-5 proportionate mortality rate• Maternal(puerperal) mortality rate• Disease –specific mortality• Proportional mortality rate

Morbidity indicators

• Incidence & prevalence• Notification rate• Attendance rate at OPD, health centers etc.• Admission ,readmission & discharge rate• Duration of stay in hospitals• Spell of sickness or absence from work or

school

Disability rates A) Event type indicators 1) number of days of restricted activity 2) bed disability days 3) work loss days (or school loss days)

with in a specific period B) person type indicators 1)limitation of mobility 2)limitation of activity

Sullivan’s index (expectation of life free of disability)HALEDALYQALY

Nutritional status indicators

• Anthropometric measurement of preschool children

• Height (or weight)of children at school entry

• Prevalence of low birth weight (<2.5kg)

Health care delivery indicators

• Doctor- population ratio• Doctor –nurse ratio• Population- bed ratio• Population per health / sub center• Population per traditional birth attendant

Utilization rates

• Proportion of infant fully immunized against 6EPI diseases

• Proportion of pregnant women who receive antenatal care

• Percentage of population using the various methods of family planning

Indicators of social & mental health

• Suicide , homicide, violence ,alcohol ,drug abuse, smoking

• Family violence ,battered baby or battered wife syndrome

Environmental indicators

• Air & water pollution• Radiations • Solid waste• Exposure to toxic • Access to safe water & sanitation

Socio –economic indicators

• Rate of population increase • Per capita GNP• Level of unemployment• Dependency ration• Literacy rate • Family size• Housing : number of person per room• Per capita calorie availability

Developed & developing region

• Social & economic

• Demographic characteristics

• Contrast in health (health gap)

Developing countries-high mortality

Developing countries-low mortality

Developed countries

Intentional injuryUnintentional injuryCardiovascular dsNeuropsychiatric disorderChronic respiratory Ds

Nutritional defeciencies Respiratory DsMaternal & perinatal conditionInfectious & parasitic Ds

Amount & pattern of burden Ds in Developing & developed countries

Selected health & socio-economic indicatorsLest developed countries

Other developing countries

Developed countries

1.Life expectancy at birth (2004) 52 65 79

2.IMR(per 1000 live birth)(2004) 98 52 5

3.Under 5 mortality/1000live birth (2004)

155 87 6

4.Matarnal mortality /100000live birth (2000) 890 440 13

5.Doctor -population ratio per 10000(1993)

1.4 8.4 25.2

6.Nurse –population ratio /10000 2.2 9.6 74.2

7.GNI per capita (US$) 2004 345 1524 32232

8.Per capita public expenditure on health ,US$ in % of GDP (1999)

5 4 14

9.Adult literacy (%) 2004 54 77 97

10.Access to safe water % population 2002 58 79 100

11.Per capita calorie(1997) 2099 2663 3371

Health services philosophies• Health care : “multitude of services rendered to

individuals ,families or communities by the agents of the health services or professions for the purpose of promoting, maintaining or restoring health.”

• Health care include -“medical care” refers chiefly to those personal services that are provided directly by physicians or rendered as a result of the physician’s instruction”

Characteristics of health care

• Appropriateness • Comprehensiveness• Adequacy• Availability• Accessibility• Affordability• Feasibility

Health system

• To deliver health services

• Constitute the management sector & involve Organizational matters e.g. planning ,

determining priority, mobilizing & allocating resources, translating policies in services, evaluation &health education.

Components of health system

• Concepts• Ideas • Objects • Persons

Aim of health system- health development

Levels of health care• Primary health care “Essential” health care PHC, Sub centers• Secondary health care mostly curative services CHC, District hospitals• Tertiary health care super-speciality care provide manangerial skill teaching specialized staff

Health team concept

• Group of persons who shares common health goals & objectives, determined by community need & toward the achievement of which each member of the team contributes in accordance with her/his competence & skill,and the respecting the functions of others.

• Health team In hospital

In community

Health for all

• May 1977-World health assembly• “Attainment by all the people of world by the

year 2000 AD of level of health that will permit them to lead socially & economically productive life”

• Health for all by 2000- essential principle is concept “equity in health”

Primary health care

• 1978-Alma-Ata,USSREssential health care based on practical, scientifically sound &

socially acceptable methods & technology made universally accessible to individuals & families in the community through their full participation & at the cost that the community and the country can afford to maintain at every stage of their development in the spirit of self-determination

• Accepted to achieve the goal of “Health for all by 2000”• “Health by people” “placing peoples health in people’s hands”

Declaration of Alma Ata

Primary health care include at least• Education about prevailing health problems and methods of

preventing & controlling them• Promotion of food supply & proper nutrition• An adequate supply of safe water basic sanitation• Maternal & child health care ,including family planning• Immunization against infectious diseases• Prevention & control of endemic diseases• Appropriate treatment of common diseases & injuries• provision of essential drug

Millennium Development Goal

Sep 2000 ---- Govt set date of 2015 GOALS are-Eradicate extrime poverty & hungerAchieve universal primary education

Concept of Disease• Disease ?• Oxford English dictionary: a condition of the body or same part or organ

of the body in which its function are disrupted or deranged. • Webster: a condition in which body health is impaired, a departure from a

state of health, an alteration of the human body interapting the performance of vital fufncions

• Ecological view : a maladjustment of the human organism to environment• Sociology view: disease is considered as social phenomenon, occurring in

all societies & define & fought in terms of the the perticular cultural forces prevalent in society

• Simplest definition is : any deviation from normal functioning or state of completeness physical & mental well-being- since health & disease is mutually exclusive .

Concept of Disease

Disease – is physiological/psychological dysfunction

Illness – is a subjective state of the person who feels aware of not being well

Sickness – is a social dysfunction , i.e. the role that the individual assumes when ill (sickness roll)

Concept Of CausationSupernatural theory of disease, theory of humors, concept of

contagion,miasmatic theory of disease, theory of spontaneous generetion

• Germ theory of disease• Epidemiological triad Environment

Agent Host• Multifactorial causation • Web causation

Changes in life style Stress SmokingAbundance of food lack of Emotional physical disturbances exercise Aging & other factor

Obesity Hypertension

Hyperlipidaemia Increase catacholamines thrombotic tendency Changes in walls of arteries Coronary atherosclerosis coronary occlusion Myocardial ischaemia Myocardial infarction

Web of causation for Myocardial infarction

Natural History Of Disease • Prepathogenesis phage disease agent not yet entered but the factors which

favour its interaction with human host already existing in environment

i.e the process in environment

• Pathogenesis phage this phage begins with the entry of the disease Agent in

the susceptible human host i.e. the process in the man

Prepathogenesis phage

Epidemiologic concept of interaction of Agent ,Host and Environment

Agent factors

Biological agent Infectivity Pathogenicity Virulence

Nutrient agent Physical agent Chemical agent Mechanical agent Absence or insufficiency or excess of a factor necessary to

health

Host factor • Demographic characteristics-e.g. age, sex, ethnicity• Biological characteristics –genetic, blood group,

enzymes, cellular constitute of blood• Social & economic characteristics- socio-economic

status, education, occupation , stress, marital status• Life style factor – personality trait ,living habits,

nutrition ,physical activity, smoking, use of alcohol

Environmental factors (extrensic)

• Physical environment – non –living things & physical factors (air,water,soil,housing,climate etc.)

• Biological environment – living things(viruses,bacteria,insect etc.) surrounding man, including man himself

• Psychosocial environment –those factors affecting personal health ,health care and community wellbeing that stem from the psychosocial make up of individual & function of social group. It include cultural values, customs,habits,beliefs.

PERIOD OF PRE-PATHOGENESIS PERIOD OF PATHOGENESIS

DISEASE PROCESS

Before man is involved

Agent Host

environmental factors(known & unknown)Bring agent & host together or produce a disease provoking stimulus

LEVELS OF PREVENTION

PRIMARY PREVENTION SECONDARY TERTIARYPREVENTION PREVENTION

MODES OF INTERVENTION

HEALTH SPECIFIC PROMOTION PROTECTION

DISABILITY REHABILITATION LIMITATION

In the Humanhost

Risk factors• Where the disease agent is not firmly established ,the etiology is generally

discussed in terms of “risk factor”• 2 meanings a. an attributes or exposure that is significantly associated with the

development of disease b.a determinant that can be modified by intervention, thereby reducing

the possibility of occurrence of disease or other specified outcome Disease Risk factors

Heart disease Smoking,high blood pressure,elevated serum cholesterol,diabetes,obesity,lack of exercise

Cancer Smoking,alcohol,solar radiation,ionising radiation,work site hazards,environmental pollution,infectious agent ,dietary factors

Stroke High blood pressure,elevated cholesterol,smoking

Motor vehicle accidents

Alcohol ,non-use of seat belts,speed, roadway desing,automobile desing

Diabetes Obesity,diet

Cirrhossis of liver

alcihol

Risk groupsguideline for defining “at-risk” group

a.Biological situation:- Age group e.g.Infants(LBW),toddlers,elderly- Sex eg females in reproductive age group- Physiological state pregnancy,cholesterol level- Genetic factors –family h/o genetic disease- Other health conditions(disease,physical functioning,unhealthy behaviour)b.Physical situation : -rural,urban slums-living conditins,overcrowding-environment : water supply,proximity to industryc.Sociocultural & cultural situatiion: -social class-ethnic & cultural group-family disrruption ,education

Spectrum of disease

Subclinicalinfection

Mild ,moderate ,severe cases

Fatal illness

Iceberg Of Disease

Symptomatic disease

Pre-symptomatic disease

What physician sees

What physician does not sees

CONCEPTS OF CONTROL • AIM IS REDUCE 1. The incidence of disease 2. The duration of disease & risk of

transmission 3.The effect of infection , including both

physical & psychosocial complication 4.the financial burden to the community

Control Elimination Eradication disease agent is permitted to persist in

community at a level where it ceases to be a public health problem according to the local population.

A state of equilibrium between Agent e.g. Malaria control

Host Environment

Control Elimination Eradication

Interruption of transmission of disease from large geographical region or area

It is intermediate goal e.g. Measles, Polio , Diphtheria

Control Elimination Eradication

Termination of all transmission of infection by extermination of the infectious agent .

Cessation of infection or disease from whole world

“Tear out by roots” e.g. Smallpox In future – Polio , Measles , Dracunculiasis

Monitoring & Surveillance

• The performance & analysis of routine measurements aimed at detecting changes in environmental or health status of population

• In management – the continuous oversight of activities to ensure that they are proceeding according to plan. It keeps track of achievements, staff movements and utilisation ,supplies & equipment & the money spent in relation to the resources available so that if any thing goes wrong ,immediate corrective measures can be taken.

Monitoring & Surveillance• The continuous scrutiny of the factor that determined the

occurrence & distribution of disease & other condition of illness.

• Objectives: 1.To provide information about new & changing trend in health

status of population .e.g. morbidity .mortality ,nutritional status, environmental hazards .

2.To provide feed-back which expected to modify the policy & system itself &lead to redefinition of objective.

3. Timely warning of public health disasters so that intervention can be modify.

“Sentinel surveillance”

CONCEPTS OF PREVENTIONSuccessful prevention depends on

-Knowledge of causation -Dynamics of transmission-Identification of risk factor & groups-Availability of prophylactic or early detection & treatment

-An organization to apply these measures

LEVELS OF PREVENTIONPrimordial prevention

Primary prevention

Secondary prevention

Tertiary prevention

Modes of Intervention • Health promotion • Specific protection

• Early diagnosis & treatment

• Disability limitation

• Rehabilitation

Health promotion

- Health education

- Environmental modification

- Nutritional intervention

- Lifestyle & behavioral changes

Specific Protection Immunization Use of specific nutrients Chemoprophylaxisis Protection against occupational hazards Protection against accidents Protection from carcinogens Avoidance of allergens The control of general environment e.g.air pollution, noise control Control of consumer product quality safety of food, drugs,

cosmetic

Early diagnosis & treatment

• Early detection of health impairment- “the detection of disturbance of homoeostatic & compensatory mechanism while biochemical, morphological & functional changes are still reversible.”

(WHO)

• MASS TREATMENT APPROCH

Disability limitation

• Disease Impairment Disability Handicaps

Impairment “Any loss or abnormality of psychological, physiological or anatomical structure or function”e.g. loss of foot, defective vision , mental retardation

Impairment may Visible or invisibleTemporary or permanentProgressive or regressiveOne may leads to other

Disability

• “Any restriction or lack of ability to perform an activity in the manner or within the range considered normal for human being”

HANDICAP

• “A disadvantage for a given individual, resulting from an impairment or a disability ,that limits or prevents the fulfillment of a role that is normal for (depending on age ,sex, social & cultural factors) that individual”

Example--Accident• Accident……..Disease( or disorder)• Loss of foot…………impairment(extrinsic 0r intrensic)• Can not walk …………Disability(objectified)• Unemployment ……………Handicap(socialized)

Rehabilitation

• Medical rehabilitation- restoration of function• Vocational rehabilitation- restoration of the

capacity to earn• Social rehabilitation- restoration of family and

social relation• Psychological rehabilitation-restoration of

personal dignity & confidence

CHANGING PATTERN OF DISEASE

Developed Country

The leading cause of death in the United Stastes 1900 & 1994

Cause of death % death from cause 1900Pneumonia 11.8Tuberculosis 11.3Diarrhoea & enteritis 8.3Heart disease 8.0Cerebrovascular disease 6.2Chronic nephritis 4.7Accidents 4.2Cancer 3.7Certain disease of infancy 3.6Diphtheria 2.3 1994Heart disease 32.1

Cancer 23.5Cerebrovascular disease 6.8Accidents 3.9COPD 4.5Pneumonia & influenza 3.6Diabetes 2.4Suicide 1.4Chronic liver Ds & cirrhosis of liver 1.1HIV infection 1.8All other cause 18.9

CHANGING PATTERN OF DISEASE

• Developing Country In typical developing country 40% Deaths

from infectious , parasitic and respiratory disease .

Diarrhoeal disease is wide spread.

CHANGING PATTERN OF DISEASE

Devloped country “Silent epidemic” e.g. Alzheimer’s disease,

Mental disorders Developing country

Mixture of old & “Modern”

• Knowledge about human health & disease classified as Basic Sciences

Clinical Sciences Population Medicine

POPULATION MEDICINE-Public Health-Preventive Medicine -Community Health-Social Medicine -Community Medicine

Public Health• The science & art of preventing disease, prolonging life &

promoting health & efficiency through organized community effort for the sanitation of the environment ,the control of communicable infection, the education of the individual in personal hygiene, the the organization of medical & nursing services for early diagnosis & preventive treatment of diseases & the development of social machinery to ensure every individual a standard of living adeqaute for the maintanance of health,so organizing these benefits as to enable every citizen to realize his birthright of health & longevity.

• (WHO,Winslow 1920)

Preventive Medicine• Not only the organized activity of

community to prevent occurrence as well as

progression of disease,disability ,mental &physical,but timely application of all means to promote the health

of individual ,and the community as the the whole , including prophylaxisis, health education & similar work done by good doctor in looking after individuals & families.

Social Medicine • Social medicine stands up on two pillars,medicine

& sociology .social medicine, by derivation is concerned with the health of group of individual & individuals within these group with a view to create ,promote, preserve and maintain health optimum health.the laboratory to practice social medicine is the whole whole community; tool for diagnosis community llness is epidemiology & biostatastics:and social therapy does not consist in administration of drug but social &political action for the betterment of condition of life of man. Social medicine is one more link in the chain of social organizations of civilized community ,

Community medicine• The field concerned with the study of health and disease in

the population of a defined community or group.

• Goal – To identify health problem and needs of defined population. – To plan, evaluate, the extent to which health measures

effectively meet these needs.

• Diagnosis of the state of health of a community is an important foundation of community medicine.

• Focus on health need of community as a whole.

Hospital & Community• Diagnosis of the patient in an individual patient in hospital

based on signs and symptoms.• In community diagnosis is based on pattern of disease in

community described in terms of important factors which influence this pattern.

• Hospital care – assessment of state of health of individual, clinical diagnosis, laboratory diagnosis, individual state of nutrition, level of development, social and emotional state.

• Community care – physician is the leader of “health team”. Provides primary health care through health team at grass root level. Familier with community diagnosis.