Sociology of Health Care Chapter 2 Epidemiology

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

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

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

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

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 2006 _among persons less than one year__ x 1000 Number of live births during 2006

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

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

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

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

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

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