Ch 1-2; 5 Flashcards
What are the 7 uses of epidemiology?
- study the history of the health of populations
- diagnose the health of the community
- study the working of health services
- estimate from group experience the individual risks
- identify syndromes
- complete the comical picture
- search for causes of disease and health
What’s the general definition of epidemiology
study of the occurrence and distribution of health-related events, states, and processes in specified populations.
what is public health practice?
the strategic, organised, and interdisciplinary application of knowledge, skills, and competencies necessary to perform essential public health services and other activities to improve the population’s health.
what does it mean when we say that epidemiology is interdisciplinary?
that the field integrates the knowledge, methods, and insights from multiple fields of science to study and address health-related issues.
what are some public health topics and concerns in epidemiology?
- foodborne illnesses
- infectious diseases (and noninfectious)
- injuries
- pregnancy-related topics
- sexually transmitted diseases
what are some key aspects of the definition of epidemiology that pertain to epidemics?
- determinants
- distribution
- population
- health phenomena
- morbidity and mortality
what are ‘determinants’ in epidemiology?
- The causes or risk factors that contribute to the occurrence of disease or health conditions.
- Factors or events that are capable of bringing about a change in health
What are the causes or risk factors that contribute to the occurrence of disease or health conditions referred to as?
Determinants
what is ‘distribution’ in epidemiology?
The pattern of how a disease spreads across different populations, regions, or time periods
What are the patterns of how a disease spreads across different populations, regions, or time periods referred to as?
Distribution
what is ‘population’ in epidemiology?
The specific group of individuals affected by or at risk of a disease
what is the specific group of individuals affected by or at risk of a disease referred to as?
Population
what is ‘health phenomena’ in epidemiology?
The various health-related events studied in epidemiology, such as infections, chronic illnesses, or outbreaks
what is the various health-related events studied in epidemiology, such as infections, chronic illnesses, or outbreaks referred to as?
Health phenomena
what is ‘morbidity and mortality’ in epidemiology?
The frequency of disease (morbidity) and the number of deaths (mortality) within a population
what is the frequency of disease and the number of deaths within a population referred to as?
morbidity; mortality
what are examples of determinants?
- biologic agents, such as bacteria, virus
- chemical agents, such as carcinogens
- less-specific factors such as stress, drinking, sedentary lifestyle, or high-fat diet
epidemiology is often referred to as ______ medicine.
‘population medicine’
the term ‘burden of disease’ is used to describe what?
how a disease may affect a population with respect to morbidity from illnesses that result in mortality and injuries.
ex. in 2017, death rates from coronary heart disease were higher amongst African Americans than Native Americans, Asian/Pacific Islanders, or whites.
coronary heart disease occurrence differs between Hispanics and non-Hispanics. This is an example of what?
burden of disease.
what are some aims of epidemiology?
- describe the health status of populations
- to explain the etiology of disease
- to predict the occurrence of disease
- to control the occurrence of disease
what fields does epidemiology draw from that make it interdisciplinary?
biostatistics, social and behavioral sciences, as well as medically related fields of toxicology, pathology, virology, genetics, microbiology, and clinical medicine.
an illness caused by an infectious agent that can be transmitted from one person to another is called what?
communicable disease
what is a communicable disease?
An illness caused by an infectious agent that can be transmitted from one person to another
what is infectious disease?
a synonym for communicable disease
what is an outbreak?
a localised disease epidemic, e.g., in a town or healthcare facility
a localised disease epidemic, e.g., in a town or healthcare facility is called what?
an outbreak
in current thinking, an epidiemic is _____ confined to infectious diseases
NOT
what does endemic mean?
a disease that is habitually present in a particular geographic region
a disease that is habitually present in a particular geographic region…
endemic
In around 400 BCE, Hippocrates wrote ‘On Airs, Waters, and Places’ in which he argued what concerning disease?
that disease may be associated with the physical environment, which was a direction away from the supernatural explanation of disease causation.
Bernardino Ramazzi is the father of _____ medicine
occupational
What is significant about John Graunt’s contributions to epidemiology?
- he recorded seasonal variations in birth and deaths
- showed excess male over female differences in mortality
- Yearly Mortality Bill for 1632: the 10 Leading Causes of Mortality in Graunt’s Time
What is significant about Edward Jenner’s contribution to epidemiology?
Conducted experiments to create a smallpox vaccine
What’s significant about John Snow’s contribution to epidemiology?
He investigated a cholera outbreak that occurred during the mid-19th century in Broad Street, Golden Square, London. His methods of isolating where the occurrence of disease took place where revolutionary. (natural experiment).
what is a ‘natural experiment’?
naturally occurring circumstances in which subsets of the population have different levels of exposure to a supposed causal factor in a situation resembling an actual EXPERIMENT. The presence of persons in a particular group is typically nonrandom
What’s significant about Ignaz Semmelweis contributions to epidemiology?
- Observed higher mortality rate among the women on the teaching wards for medical students and physicians than on the teaching wards for midwives
- Postulated that medical students and physicians had contaminated their hands during autopsies
- Introduced the practice of handwashing
What’s significant about William Farr’s contributions to epidemiology?
- Provided foundation for classification of diseases (ICD system)
- Used data such as census reports to study occupational mortality in England
- Examined linkage between mortality rates and population density
what was known as the Mother of All Pandemics?
1918 Influenza Pandemic. 2.5% case-fatality rate vs 0.1% for other influenza pandemics, killed 50 - 100 million people worldwide.w
what has replaced acute infectious diseases as major causes of morbidity and mortality?
chronic diseases (e.g., heart disease, cancer, chronic lower respiratory disease).
what factors affect the reliability of observed changes in cause of morbidity and mortality?
- Lack of comparability over time due to altered diagnostic criteria
- Aging of the general population
- Changes in the fatal course of the condition
What are four trends in disorders?
- Disapearring
- Residual
- Persisting
- New epidemic
What does a ‘disappearing disorder’ mean?
refers to conditions that were once common but are no longer present in epidemic form (e.g. smallpox). Brought under control by means of immunizations, improved sanitary conditions, and the use of antibiotics and other medications.
This type of disorder refers to conditions that were once common but are no longer present in epidemic form (e.g. smallpox). Brought under control by means of immunizations, improved sanitary conditions, and the use of antibiotics and other medications.
disappearing
What does a ‘residual disorder’ mean?
Conditions for which the key contributing factors are largely known. e.g. STDs, Perinatal and infant mortality among low SES persons.
Conditions for which the key contributing factors are largely known. e.g. STDs, Perinatal and infant mortality among low SES persons are what sort of disorder?
residual
What does a ‘persisting disorder’ mean?
Diseases for which there is no effective method of prevention or no known cure.
Diseases for which there is no effective method of prevention or no known cure describe what sort of disorder?
persisting
What does a ‘new epidemic disorder’ mean?
Diseases that are increasing in frequency in comparison with previous time periods, e.g. lung cancer, alzheimer’s..
Diseases that are increasing in frequency in comparison with previous time periods, e.g. lung cancer, alzheimer’s are what sort of disorder?
new epidemic
new epidemics of disease might result from what sort of factors?
- increased life expectancy
- new environmental exposures
- changes in lifestyle and diet
A population pyramid represents what?
The age and sex composition of the population of an area or country at a point in time. By examining the distribution of a population by age and sex, one may view the impact of mortality from acute and chronic conditions
In a population pyramid, less developed countries have what shape? Why?
A triangular shape due to high death rates from infections, high birth rates, and other conditions.
In a population pyramid, developed countries have what shape? Why?
- Manifest a rectangular population distribution.
- Infections take a smaller toll and cause a greater proportion of children to survive into old age.
- Residents enjoy greater life expectancy.
- The population of developed countries will grow increasingly older due to continuing advances in medical care.
What are two types of populations?
fixed and dynamic
what is a fixed population?
Adds no new members and, as a result, decreases in size due to deaths only.
what is a dynamic population?
Adds new members through immigration and births or loses members through emigration and deaths
What 3 major factors affect the size of populations?
- Births
- Deaths
- Migration
What are some demographic and social variables in a population to consider in epidemiology?
- age and sex distribution
- socioeconomic staus
- family structure
- racial, ethnic, and religious composition
What are some variables related to community infrastructure?
- availability of social and health services
- quality of housing stock
- social stability
- community policing
- employment opportunities
What are some health-related outcome variables?
- Homicide and suicide rates
- Infant mortality rate
- Chronic and infectious diseases
- Drug and alcohol abuse rates
- Teen pregnancy rates
- Sexually transmitted diseases
- Birth rate
What are some examples of environmental variables to consider?
- Air pollution from stationary and mobile sources
- Access to playgrounds and public parks
- Availability of nutritious and healthful foods
- Number of liquor stores and fast-food outlets
- Sugar-laden beverages sold in vending machines
- Overcrowding with associated unsanitary conditions
what are health disparities?
differences in health outcomes that are closely linked with social, economic, and environmental disadvantage
differences in health outcomes that are closely linked with social, economic, and environmental disadvantage are known as what?
health disparities
What are some examples of public health policies that have come about as a result of epidemiologic research?
- Fluoridation of water
- Helmet protection for motorcycle riders
- Mandatory seat belt use in motor vehicles
- Requiring automobile manufacturers to install air bags in vehicles
what is operations research?
the systematic study, by observations and experiment of a system (e.g., health services) with a view to improvement.
the systematic study, by observations and experiment of a system (e.g., health services) with a view to improvement refers to what?
operations (operational) research
What are some topics addressed by operations research?
- Identifying unmet needs for service
- Identifying duplicated health services
- Studying healthcare utilization
- Identifying underserved segments of the community
- Studying the organization of services
Due to the uncertainty of ‘causal’ factors, what term is used in its stead?
risk factors
what’s the definition of risk factors?
exposure that is ASSOCIATED with a disease, e..g smoking is a risk factor of lung cancer.
what are the three criteria for risk factors?
- The frequency of the disease varies by category or value of the factor (e.g., light smokers vs. heavy smokers).
- The risk factor precedes onset of the disease.
- The observation must not be due to error.
what are the five criteria for causality? (9, including the ones Sir Austin Bradford Hill expanded on)
- Strength of association
- Time sequence
- Consistency upon repetition
- Specificity
- Coherence of explanation
(Hill expanded the list of criteria to include:) - Biologic gradient
- Plausibility
- Experiment
- Analogy
What are the two main types of observational studies for research on disease etiology?
- Case-control
- Cohort
What is case-control design?
A type of design that compares persons who have a disease (cases) with those who are free from the disease (controls).
A type of design that compares persons who have a disease with those who are free from the disease is called what?
case-control
what is cohort control?
A group of people free from a disease is assembled according to a variety of exposures. The group (cohort) is followed over a period of time for development of disease.
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. This is known as what?
cohort control
what does prepathogenesis mean in the natural history of disease?
before the precurses of disease react with host.
what does pathogenesis means in the natural history of disease?
after the precursors have interacted with the host
what are the stages of the natural history of disease?
- prepathogenesis
- pathogenesis
- development of active signs and symptoms
- clinical end points in recover, disability, or death
what is primordial prevention?
Denotes “conditions, actions and measures that minimize hazards to health”
what are some examples of primary prevention?
- Wearing protective devices to prevent occupational injuries
- Use of specific dietary supplements
- Immunizations
- Educational campaigns against unintentional injuriesVa
vaccinations and wearing protective devices are examples of what type of primary prevention of disease?
active
fluoridation of public water and vitamin fortifications of milk and bread products is an example of what type of primary prevention of disease?
passive
what is secondary prevention of disease?
- Occurs during pathogenesis phase
- Encompasses early diagnosis, prompt treatment, and disability limitation
- Designed to reduce the progress of disease
- Examples are screening programs for cancer
what is tertiary prevention of disease?
- Takes place during late pathogenesis (advanced disease and convalescence stages)
- Designed to limit disability from disease
- Also directed at restoring optimal functioning (rehabilitation)
- Examples include physical therapy for stroke patients, halfway houses for alcohol abuse recovery, and fitness programs for heart attack patients
Why are data crucial for epidemiology and public health practice?
- Need to characterize whole populations
- Requirement of adequate numbers for statistical inference
- Low frequency conditions
- Accumulation of sufficient numbers of at-risk individuals to obtain reliable estimates
What are some newer methods for collecting public health data?
- EMRs
- Post on social media
- Technological developments (smartphones, wearable technology)
What are five types of epidemiologic data?
- Research data
- Surveillance data
- Administrative data
- Environmental data
- Patient-related data
How is big data used in epidemiology and public health practice?
- surveillance of health conditions
- chronic disease research (with large subject pools)
- data from population-based registries
What are the four criteria for the quality and utility of the epidemiologic data?
- the nature of the data
- the availability of the data?
- the completeness of population coverage
- strengths vs limitations
what does the nature of data refer to?
to the source of data, such as:
- Vital statistics
- Case registries
- Records from medical practice
- Surveys of the general population
- Cases from hospitals and clinics
what does the availability of data refer to?
Refers to investigator’s access to data
what does the completeness of population coverage refer to?
- Representativeness: The degree to which a sample resembles a parent population
- Generalizability (external validity): The ability to apply findings to a population that did not participate in the study
- Thoroughness: The care taken to identify all cases of a given disease
what factors inherent in big data may limit its usefulness? 2 big answers
- case duplication
- incomplete diagnostic information
what are some major online sources of epidemiologic data and research?
online bibliographic databases such as MEDLINE, the National Library of Medicine’s PubMed, and NLM’s toxicology services.
confidentiality laws require that researchers maintain what?
adequate safeguards for privacy and confidentiality of data from human subjects
what are some major laws and acts in place addressing confidentiality?
- Privacy Act of 1974
- Prohibits the release of confidential data without the consent of the individual - Freedom of Information Act
- Mandates the release of government information to the public, except for personal and medical files - The Public Health Service Act
- Protects confidentiality of information collected by some federal agencies, e.g., NCHS - HIPAA
-Categories of protected health information pertain to individually identifiable data related to:
-Individual’s physical and mental health
-Provision of health care to the individual
-Payment for provision of health care
what does the sharing of data refer to?
voluntary release of information by one investigator or institution to another for the purpose of scientific research
what is the key issue in sharing of data?
Key issue is the primary investigator’s potential loss of control over information
what is record linkage?
Joining data from two or more sources
- Example: employment records and mortality data
what sorts of statistics are derived from the vital registration system?
mortality stats and birth rates (including fetal death)
what are some limitations of mortality data?
- certification of cause of death (e.g., in an elderly person with a chronic illness, exact cause of death may be unclear)
- lack of standardization of diagnostic criteria
- stigma associated with certain diseases may lead to inaccurate reporting
mortality data are nearly complete, because why?
most deaths in the U.S. and other developed countries are unlikely to be unreported
