Lecture 2 health, wellbeing and disease (1).pptx

Health wellbeing and disease

1. Unit-II Concept of Health & Disease

2. Objectives : At the end of this presentation the student will be able to: Discuss the terms of Health, Disease, Well being. Describe the concept of causation. Understand the Health indicator . 2

3. CONCEPT OF HEALTH Health is evolved over the centuries. Changing concept of health till now are: Biomedical concept Ecological concept Psychosocial concept Holistic concept 3

4. BIOMEDICAL CONCEPT Traditionally, health has been viewed as an “absence of disease”, and if one was free from disease, then the person was considered healthy. This concept has the basis in the “germ theory of disease”. The medical profession viewed the human body as a machine, disease as a consequence of the breakdown of the machine and one of the doctor’s task as repair of the machine. 4

5. ECOLOGICAL CONCEPT Form ecological point of view; health is viewed as a dynamic equilibrium between human being and environment, and disease a maladjustment of the human organism to environment. According to Dubos “Health implies the relative absence of pain and discomfort and a continuous adaptation and adjustment to the environment to ensure optimal function.” 5

6. PSYCHOSOCIAL CONCEPT According to psychosocial concept “health is not only biomedical phenomenon, but is influenced by social, psychological, cultural, economic and political factors of the people concerned.” 6

7. HOLISTIC CONCEPT This concept is the synthesis of all the above concepts. It recognizes the strength of social, economic, political and environmental influences on health. It described health as a multi dimensional process involving the wellbeing of whole person in context of his environment . 7

8. WHAT IS Health? “A state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity” WHO. (1948). 8

9. RISK FACTORS & DETERMINANTS Risk Factor is any attribute, characteristic or exposure of an individual that increases the likelihood of developing a disease or injury. Some examples of the more important risk factors are underweight, unsafe sex, high blood pressure, tobacco and alcohol consumption, and unsafe water, sanitation and hygiene. Determinant of Health: Many factors combine together to affect the health of individuals and communities . 9

10. determinants of health The determinants of health include: Socio- economic Physical Person’s individual characteristics & behaviours . 10

11. Communities Individuals Families Societies 11 DETERMINANTS OF HEALTH

12. Well-being "Well-being is a subjective perception of vitality (energy) and feeling well.....can be described objectively, experienced, and measured......and can be plotted ( design) on a continuum". It is a component of health.

13. CONCEPT OF WELLBEING Wellbeing of an individual or group of individuals have several components and has been expressed in various ways, such as ‘standard of living’ or ‘level of living’ and ‘quality of live’. 13

14. WELLBEING Wellbeing of an individual or group of individuals have objective (standard of living or level of living) and subjective (quality of life) components. Thus, a distinction is drawn between the concept of ‘level of living’ consisting of objective criteria and of ‘quality of life’ comprising the individual’s own subjective evaluation of these. 14

15. TWO ASPECTS OF HEALTH Subjective: It is formed by sensations and feelings of a person suffering from disease. Objective: Its basis is formed by objective parameters obtained by measurement of structures and functions of a person during disease. The quality of life can be evaluated by assessing the persons subjective feeling of happiness or unhappiness about the various life concerns. 15

16. Wellness & Well-Being Wellness further describes health status. It allows health to be placed on a continuum from one’s optimal level (“wellness”) to a maladaptive state (“illness”)

17. Wellness Wellness is a dynamic process that is ever changing. The well person usually has some degree of illness and the ill person usually has some degree of wellness.

18. Cont … The classic description of wellness was developed by Dunn in the early 1960s. According to Dunn (1961), high-level wellness means functioning to one’s maximum health potential while remaining in balance with the environment.

19. Copyright 2008 by Pearson Education, Inc. Health-Illness Continuum Measure person’s perceived level of wellness Health and illness/disease opposite ends of a health continuum Move back and forth (forward) within this continuum day by day Wide ranges of health or illness

20. Copyright 2008 by Pearson Education, Inc. Dimensions of Wellness

21. 1. Physical The ability to carry out daily tasks, achieve fitness (e.g. pulmonary, cardiovascular, gastrointestinal), maintain adequate nutrition and proper body fat, avoid abusing drugs and alcohol or using tobacco products, and generally to practice positive lifestyle habits.

22. 2. Social. The ability to interact successfully with people and within the environment

23. 3. Emotional. The ability to manage stress and to express emotions appropriately, Emotional wellness involves the ability to recognize, accept, and express feelings.

24. 4 . Intellectual . The ability to learn and use information effectively for personal, family, and career development

25. 5. Spiritual. The belief in some force (nature, science, religion, or a higher power) that serves to unite human beings and provide meaning and purpose of life

26. 6. Occupational. The ability to achieve a balance between work and leisure time, A person's beliefs about education, employment, and home influence personal satisfaction and relationships with others.

27. 7. Environmental . The ability to promote health measures that improve the standard of living and quality of life in the community

28. CONCEPT OF DISEASE Webster defines disease as “a condition in which body health is impaired, a departure from a state of health, an alteration of the human body interrupting the performance of vital functions”. The oxford English Dictionary defines disease as “ a condition of the body or some part or organ of the body in which its functions are disturbed or deranged”. 28

29. CONCEPT OF DISEASE Ecological point of view disease is defined as “a maladjustment of the human organism to the environment.” The simplest definition is that disease is just the opposite of health: i.e. any deviation from normal functioning or state of complete physical or mental well-being. 29

30. Distinction between Disease, Illness and Sickness The term disease literally means “without ease” (uneasiness), when something is wrong with bodily function. Illness refers to the presence of a specific disease, and also to the individual’s perceptions and behavior in response to the disease, as well as the impact of that disease on the psychosocial environment. Sickness refers to a state of social dysfunction. 30

31. Distinction between Disease, Illness and Sickness Disease is a physiological/psychological dysfunction. Illness is a subjective state of the person who feels aware of not being well. Sickness is a state of social dysfunction i.e. a role that the individual assumes when ill (sickness role). 31

32. MODELS/THEORIES OF DISEASE CAUSATION Human disease results from an interaction of the Host Agent Environment Disease causation is usually described in terms of four models: Germ theory Epidemiologic Triad Wheel of Causation Web of Causation 32

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34. Epidemiological Triad The best known, but most dated model of disease (communicable) is the “ Epidemiologic Triad” . According to this model disease results from an interaction among; Agent Host Environment 34

35. Epidemiological Triad Agent — cause of the disease Host — Living things, usually humans or animals, which are exposed to and harbor a disease. Environment —external factors that cause or allow disease transmission. 35

36. Epidemiological Triad The mere presence of agent, host and environmental factors is not sufficient to start the disease in man. It is the interaction of theses factors; that is required to initiate the disease process in man. 36

37. EPIDEMIOLOGICAL TRIAD: EXAMPLES 37

38. EPIDEMIOLOGICAL TRIAD 38

39. DISEASE AGENTS Biologic (Infectious agents, insect and animal allergens) Chemical ( Air pollutants , toxic wastes , pesticides) Physical (Noise, radiation, heat, cold, electricity) 39

40. AGENTS Mechanical Agents (Exposure to chronic friction & other mechanical forces may result in crushing, tearing, sprains, dislocation& even death) Social (poverty, access to health care, social isolation, deprivation) 40

41. Web of causation McMahon and Pugh forwarded the theory of “epidemiological web of causation”, wherein the various factors (e.g. hypercholesterolemia, smoking, hypertension) are like an interacting web of a spider. Each factor has its own relative importance in causing the final departure from the state of health, as well as interacts with others, modifying the effect of each other. 41

42. 42 WEB OF CAUSATION

43. The Wheel of Causation Wheel theory: As medical knowledge advanced, an additional aspect of interest that came into play is the comparative role of “genetic” and the “environmental” (i.e. extrinsic factors outside the host) factors in causation of disease. The “triad” as well as the “web” theory does not adequately cover up this differential. To explain such relative contribution of genetic and environmental factors, the “wheel” theory has been postulated (Mausner & Kramer, 1985) . 43

44. The Wheel of Causation The theory de-emphasizes the agent as the sole cause of disease. The theory visualizes human disease in the form of a wheel, which has a central hub representing the “ genetic components” and the peripheral portion representing the “ environmental component” . 44

45. The Wheel of Causation Like any wheel, the outer part (environmental component) has spokes (3 in this model) and the environmental component is thus divided into 3 sub components; Physical Biological Social 45

46. NATURAL HISTORY OF DISEASE The term “Natural History Of Disease” is a key concept in epidemiology. Natural History of Disease refers to “the uninterrupted progression of the disease process in an individual over time, in the absence of intervention”. Knowledge of the natural history of disease is important for disease prevention and control. 46

47. NATURAL HISTORY OF DISEASE After contact with an infectious agent there is a theoretical point at which the disease process may begin. Without medical intervention, the process ends with: Recovery Disability or Death 47

48. NATURAL HISTORY OF DISEASE 48

49. Spectrum of Disease In some people, however, the disease process may never progress to clinically apparent illness. In others, the disease process may result in illness that ranges from mild to severe or fatal. This range is called the  Spectrum of Disease . 49

50. Spectrum of Disease Because the spectrum of disease can include asymptomatic and mild cases, the cases of illness diagnosed by clinicians in the community often represent only the tip of the iceberg. Many additional cases may be too early to diagnose or may never progress to the clinical stage. Persons with inapparent or undiagnosed infections may be able to transmit infection to others. Such persons who are infectious but have subclinical disease are called  carriers . 50

51. ICEBERG OF DISEASE PHENOMENON The Iceberg Phenomenon is the representation of disease burden of a community. Iceberg has two portions: Tip of the ice berg Submerged(hidden) part 51

52. 52 ICEBERG OF DISEASE

53. ICEBERG OF DISEASE PHENOMENON The floating tip represents the clinically apparent cases; what the physician sees in his practice/clinic/hospital etc. The clinically apparent cases represent only a small fraction of the total cases of disease in the community. The remaining large hidden part of the iceberg represents the mass of unrecognized disease in the community (e.g., sub­clinical cases, carriers, undiagnosed cases); hidden from view of the general public or physician. 53

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55. INDICATORS OF HEALTH A variable which helps to measure changes , directly or indirectly (WHO,1981). The health indicators are defined as those variables which measures the health status of an individual and community. 55

56. INDICATORS OF HEALTH Mortality Indicators: Crude Death rate, Life Expectancy, Infant mortality rate, Child mortality rate, Under five mortality rate, Maternal mortality ratio, Disease specific mortality, proportional mortality rate etc. Morbidity Indicators: Incidence and prevalence rate, OPD attendance rate, Admission, readmission and discharge rate, duration of stay in hospital and spells of sickness or absence from work or school. 56

57. INDICATORS OF HEALTH Nutritional Status Indicators: Anthropometric measurement of preschool children, Prevalence of low birth weight etc. Health Care Delivery Indicators: Doctor-population ratio, Bed-nurse ratio, Population-bed ratio, Population per health facility etc. Utilization Rates: immunization coverage, ANC coverage, % of Hospital Delivery, Contraceptives prevalence rate, Bed occupancy rate, average length of stay in hospital etc. 57

58. INDICATORS OF HEALTH Indicators of social and mental health: Rates of suicides, violence, crimes, RTAs, drug abuse, smoking and alcohol consumption etc. Environmental indicators: proportion of population having access to safe drinking water and improved sanitation facility, level of air pollution, water pollution, noise pollution etc. Socio Economic Indicators: rate of population increase, Per capita GNP, Dependency ratio, Level of unemployment, literacy rate, family size etc. 58

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