Epi Exam 1 Flashcards
Define the term epidemiology.
The study of what befalls the population.
Epidemiology is concerned with the distribution and determinants of health and diseases, morbidity, injuries, disability, and mortality in populations.
Define determinants.
Factors or events that are capable of bringing about a change in health.
Define distribution.
Study of frequency and pattern of health events in the population.
Morbidity
Designates illness
Mortality
Refers to deaths that occur in a population
Name and describe characteristics of the epidemiologic approach.
To DESCRIBE the health status of populations.
To EXPLAIN the etiology of disease.
To PREDICT the occurrence of disease.
To CONTROL the occurrence of disease.
Hippocrates’s hypothesis
Suggested that disease might be associated with the physical environment.
Represented a movement away from supernatural explanations of disease causation.
Graunt’s contributions to biostatistics.
Recorded how many persons per year died of what kind of event or disease.
Developed and calculated life tables and expectancy.
Divided deaths into two types of causes: acute and chronic.
Define natural experiments.
The epidemiologist does not manipulate a risk factor but rather observes the changes in an outcome as the result of a naturally occurring situation.
Epidemic
Occurrence of a disease clearly in excess of normal expectancy.
Endemic
A disease or infectious agent that is habitually present in a community. Often an endemic disease maintains a low but continuous incidence.
Pandemic
An epidemic on a worldwide scale.
Surveillance
The systematic collection of data pertaining to the occurrence of specific diseases.
Epidemic Threshold
The minimum number of cases that would support the conclusion that an epidemic was underway.
Edward Jenner
Invented smallpox vaccine.
John Snow
Investigated a cholera outbreak. Linked the epidemic to contaminated water supplies.
Ignaz Semmelweis
Early pioneer of antiseptic procedures.
William Farr
Provided foundation for classification of diseases.
Robert Koch
Established germ theory.
Seven Uses of Epidemiology
To STUDY the history of the health of populations.
To DIAGNOSE the health of the community.
To STUDY the working of health services-operations research.
To ESTIMATE the individual risks of disease and other conditions, and the chances of avoiding them.
To IDENTIFY syndromes.
To COMPLETE the clinical picture of chronic diseases.
To SEARCH for causes of health and disease.
Koch’s Postulates
Microorganism must be observed in every case of the disease.
Microorganism must be isolated and grown in pure culture.
Pure culture must, when inoculated into a susceptible animal, reproduce the disease.
Microorganism must be observed in, and recovered from, diseased animal.
Four trends that reduce reliability of morbidity and mortality.
New Epidemic
Persisting
Disappearing
Residual
Disappearing Disorders
Conditions that were once common but are no longer present in epidemic form.
Residual Disorders
Conditions for which the key contributing factors are largely known.
Methods of control not implemented effectively.
Residual Disorders
Conditions for which the key contributing factors are largely known.
New Epidemic Disorders
Diseases that are increasing in frequency.
Fixed Population
Adds no new members and, as a result, decreases in size due to deaths only.
Dynamic Population
Adds new members through migration and births or loses members through emigration and deaths.
Demographic Transition
Shift from high birth and death rates found in agrarian societies to lower birth and death rates found in developed countries.
Epidemiologic Transition
Shift in the pattern of morbidity and mortality from infectious and communicable diseases to chronic, degenerative diseases.
Operations Research
The study of the placement and optimum utilization of health services in a community.
Risk Factor
Exposure that is associated with a disease.
Three Criteria for Risk Factors
The frequency of the disease varies by category or value of the factor.
The risk factor precedes the onset of the disease.
The observation must not be due to error.
Modern Concepts of Causality
Strength of Association Consistency upon Repetition Specificity Time Sequence Biologic Gradient Plausibility Coherence of Explanation Experiment - Natural Experiments Analogy - Similar Associations
Case-Control Design
A type of design that compares persons who have a disease with those who are free from the disease. This design explores whether differences between cases and controls result from exposures to risk factors.
Cohort Design
A group of people free from a disease is assembled according to a variety of exposures. The group is followed over a period of time for development of disease.
Natural History of Disease
The course of disease from its beginning to its final clinical end points.
Prepathogenesis
Before agent reacts with host.
Pathogenesis
After agent reacts with host.
Primary Prevention
Occurs during prepathogenesis phase.
Includes health promotion, education, and specific protection against diseases.
Active Prevention
Necessitates behavior change on the part of the subject.
Passive Prevention
Does not require any behavior change.
Secondary Prevention
Occurs during the pathogenesis phase. Designed to reduce progress of the disease.
Tertiary Prevention
Designed to limit disability from disease. Also directed at restoring optimal functioning.
Ratio
The value obtained by dividing one quantity by another.
In a ratio, the values of x and y are independent such that the values of x are not contained in y.
Proportion
A measure that states a count relative to the size of the group.
In a proportion, x is contained in y.
Rate
A ratio that consists of a numerator and a denominator and in which time forms part of the denominator.
Count
Refers to the number of cases of a disease or other health phenomenon being studied.
Prevalence
The number of existing cases of a disease or health condition in a population at some designated time.
Point Prevalence
= Number of persons ill / total number in the group at point in time
Period Prevalence
= Number of persons ill / average population during a time period
Incidence
The number of new cases of a disease that occur in a group during a certain time period.
Incidence Rate
Describes the rate of development of a disease in a group over a certain time period.
Attack Rate
= ill / (ill + well) * 100
Incidence Density
An incidence measure used when members of a population are under observation for different lengths of time.
Crude Birth Rate
= (Number of live births within a given period / population size at the middle of that period) * 1,000 population
General Fertility Rate
= (# of live births within a year / # of women aged 15-44 years during the midpoint of the year) * 1,000 women aged 15-44
Infant Mortality Rate
= (Number of infant deaths among infants aged 0-365 days during the year / number of live births during the year) / 1,000 live births
Fetal Death Rate
= [Number of fetal deaths after 20 weeks gestation / (number of live births + number of fetal deaths after 20 weeks gestation)] / * 1,000
Fetal Death Ratio
= (Number of fetal deaths after 20 weeks or more gestation) / number of live births) * 1,000
Neonatal Mortality Rate
= (Number of infant deaths under 28 days of rage / number of live births) * 1,000 live births
Postneonatal Mortality Rate
= (Number of infant deaths from 28-365 days after birth / number of live births - neonatal deaths) * 1,000 live births
Perinatal Mortality Rate
= (Number of late fetal deaths after 28 weeks gestation plus infant deaths within 7 days of birth / number of live births + number of late fetal deaths) * 1,000 live births and fetal deaths
Perinatal Mortality Ratio
= (Number of late fetal deaths after 28 weeks gestation plus infant deaths within 7 days of birth / number of live births) * 1,000 live births
Maternal Mortality Rate
= (Number of deaths assigned to causes related to childbirth / number of live births) * 100,000 live births
Cause-Specific Rate
= (Mortality or frequency of a given disease / population size at midpoint of time period) * 100,000
Proportional Mortality Ratio
= (Mortality due to a specific cause during a time period / mortality due to all causes during the same time period) * 100
Age-Specific Rate
= (Number of deaths among those aged 5-14 years / number of persons who are 5-14 years during time period) * 100,000
Standard Mortality Ratio
= (Observed deaths / expected deaths) * 100
Descriptive Studies
Used to identify a health problem that may exist.
Analytic Studies
Used to identify the cause of a health problem.
Hypotheses
Theories tested by gathering facts that lead to their acceptance or rejection.
Case Reports
Counts
Case Series
Summarize characteristics of patients from major clinical settings.
Cross-sectional Studies
Surveys of the population to estimate the prevalence of a disease or exposure.
Acculturation
Modifications that individuals or groups undergo when they come in contact with another country.
Nativity
Place of origin of the individual.
Social Causation Explanation
Conditions associated with lower social class produce mental illness.
Downward Drift Hypothesis
Persons with severe mental disorders move to impoverished areas.
Case Clustering
An unusual aggregation of health events grouped together in space and time.
Representativeness
How does the sample represent the parent population?
Generalizability
Ability to apply findings to a population that did not participate in the study.
Thoroughness
The extent to which all cases of a health phenomenon have been identified.
Registry
A centralized database for collection of data about a disease.
Crude Rates
Summary rates based on the actual number of events in a population over a given time period.
Healthy Migrant Effect
The observation that healthier, younger persons usually form the majority of migrants.
