Epidemiology PDF

EPIDEMIOLOGY EPIDEMIOLOGY comes from the Greek words epi, meaning on or upon, demos, meaning people, and logos, meaning the study of In other words, the word epidemiology has its roots in the study of what befalls a population EPIDEMIOLOGY scientific study of the distribution and determina...

EPIDEMIOLOGY EPIDEMIOLOGY comes from the Greek words epi, meaning on or upon, demos, meaning people, and logos, meaning the study of In other words, the word epidemiology has its roots in the study of what befalls a population EPIDEMIOLOGY scientific study of the distribution and determinants of diseases and health outcomes in populations to develop methods of controlling health problems, limit the consequences of illness, and maximize health Components: population, distribution and factors DISTRIBUTION Epidemiology is concerned with the frequency and pattern of health events in a population: Frequency refers not only to the number of health events but also to the relationship of that number to the size of the population Pattern refers to the occurrence of health-related events by time, place, and person. DETERMINANTS causes and other factors that influence the occurrence of disease and other health-related events APPLICATION involves applying the knowledge gained by the studies to community-based practice IMPORTANCE OF EPIDEMIOLOGY Assessing the community’s health What are the actual and potential health problems in the community? Where are they occurring? Which populations are at increased risk? Which problems have declined over time? Which ones are increasing or have the potential to increase? How do these patterns relate to the level and distribution of public health services available? CORE EPIDEMIOLOGIC FUNCTIONS public health surveillance field investigations analytic studies evaluations linkages policy develoipment FACTORS OF DISEASE CAUSATION Predisposing factors Enabling factors precipitating factors reinforcing factors risk factors EPIDEMIOLOGIC APPROACH descriptive epidemiology analytical epidemiology intervention or experimental evaluation epidemiology DESCRIPTIVE EPIDEMIOLOGY Describes the distributionof cases by the variables of person, time and place in order to: o Study and explain acute outbreaks of disease o Follow secular trends of disease occurrence over time o Develop hypothesis of disease transmission limited to a description of the occurrence of a disease in a population and is often the first step in an epidemiological investigation DESCRIPTIVE EPIDEMIOLOGY Absence of disease sporadic occurence endemic occurence epidemic occurence pandemic occurence 5 W’S What: The health event or diagnosis Who: The person or population involved Where: The place where the event occurred When: The time when the event occurred Why: The causes, risk factors, and modes of transmission DESCRIPTIVE EPIDEMIOLOGY Case report case series ecologic / correlational cross-sectional surveys (prevalence) ANALYTIC EPIDEMIOLOGY Concerned with determining causes of disease occurrence, specifically whether a suspected factor is causally associated with disease using observational method of testing hypothesis or cause goes further by analyzing relationships between health status and other variables ANALYTIC EPIDEMIOLOGY Community diagnosis investigation of epidemic determination of diseases etiology evaluations of community interventions and programs ANALYTIC EPIDEMIOLOGY cross sectional analytic case control cohort experimental randomized controlled trials community/field trials clinical trials VITAL STATICS FERTILITY RATES a measure of the number of births in a population and are calculated in a few different ways Crude Birth Rate: Measures how fast people are added to the population through births FERTILITY RATES a measure of the number of births in a population and are calculated in a few different ways GENERAL FERTILITY RATE: More specific rate than the crude birth rate since births are related to the segment of population deemed to be capable of giving birth FERTILITY RATES a measure of the number of births in a population and are calculated in a few different ways AGE SPECIFIC FERTILITY RATE: Shows variation in fertility by age FERTILITY RATES a measure of the number of births in a population and are calculated in a few different ways TOTAL FERTILITY RATE: Standardized index for overall fertility level Represents the average number that would be born to a women throughout her lifetime Indicator of cohort fertility MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time CRUDE DEATH RATE: Affected by age and sex composition of the population; adverse environmental condition; peace and order conditions of a place MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time CAUSE OF DEATH RATE: Affected by completeness of registrations of death; composition of population; disease ascertainment in the community which may be used to determine the 10 leading cause of death MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time INFANT MORTALITY RATE: Most sensitive index of assessing health status in the community. MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time NEONATAL MORTALITY RATE: Cause of death are mainly due to pre-natal or genetic factors MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time MATERNAL MORTALITY RATE: Affected by maternal health practices; diagnostic ascertainment; completeness of registration of births MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time CHILD MORTALITY RATE: Reflects the main environmental factors affecting health of a child Sensitive indicator of socio-economic development in a community MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time SWAROOP’S INDEX: Sensitive indicator of standard of health care. MORTALITY RATES a measure of the number of deaths in a population relative to the population's size over a period of time CASE FATALITY RATE: Measures killing power of disease High CFR means a more fatal disease. A higher CFR is expected from a hospital statistics than from the community