1. Sociology of Health Care
Chapter 2
Epidemiology

2. Scope and Definition of Epidemiology
Study of the origin and distribution of disease within a population
Primary focus on group; not on individual
Detective looking for common denominator(s) that connect all victims of a health problem together

3. Epidemiological Measures
Case = an episode of a disease, illness or injury involving a person
Incidence = number of new cases of a specific health disorder occurring within a population in a given time
Prevalence = total number of cases of a health disorder that exist at any given time

4. Prevalence expanded
Prevalence includes all existing cases plus all new cases
Point Prevalence = number of cases at a specific point in time, usually a day or week
Period Prevalence = total number or cases during a period of time, usually a month or year
Lifetime Prevalence = number of people who have had a particular health problem at least once in their lifetime

5. Epidemiological Ratios
Total number of cases of a disease compared to the total number of people within the population
Crude Rate = Cases____ Population
Crude rates often lack specificity

6. Example: Infant Mortality Rate
Significant for a society because it has been used as an indicator of standard of living and quality of health care delivery within the society
Total number of deaths in _among persons less than one year__ x 1000
Number of live births during 2006

7. The Science of Epidemiology
Epidemics have existed for centuries
No systematic way of studying them existed until the 19th century
Study of the social environment = actual living conditions such as poverty and crowding plus the attitudes, norms and values that characterize a social and cultural context

8. 3 or 4 Historical Eras Early to mid-19th Century – Sanitary Era
Focus largely on sewage and drainage systems
Late 19th to mid-20th Centuries – Infectious Disease Era
Focus on breaking the chain of transmission between agent and host

9. Second half of the 20th Century – Chronic Disease era
Focus on controlling risk factors by modifying lifestyles (i.e., diet, exercise), agents (i.e., guns, food) and/or the environment (i.e., pollution or passive smoking)
21st Century – Era of Eco-epidemiology
Multidisciplinary preventive measures

10. Multicausality Chronic and degenerative health issues Aging
Effects of man-made environments
Text example: heart disease
Risk factors
Smoking
High blood pressure
High cholesterol
Obesity
Lack of exercise

11. Disease and Modernization
Industrialized Nations
Urban
Industrtialized
Increased life expectancy
Death results from diseases of modern living: heart disease; cancer
Non-industrialized Nations
Rural
Agrarian
High infant mortality rates
Death results from infectious and parasitic diseases

12. Leading Causes of Death (see page 32 for more information)
1900
Influenza and pneumonia
Tuberculosis
Gastroenteritis
Heart disease
Cerebral hemorrhage
Kidney disease
Accidents
2002
Heart disease
Cancer
Cerebrovascular disease
Pulmonary diseases
Accidents
Diabetes
Influenza and
pneumonia