Demography
The statistical study of human populations, including the size, structure, and distribution of different populations and changes in them.
Population
The number or body of inhabitants in a place belonging to a specific social, cultural, socioeconomic, ethnic, or racial subgroup.
Demographic Analysis
A technique used to understand the age, sex, and racial composition of a population and how it has changed over time through birth, death, and migration.
Population Studies
The scientific study of human populations, including broad population dynamics, fertility and family dynamics, health, aging, mortality, and human capital and labor markets.
Count
The absolute number of a population or any demographic event occurring in a specified area and time period.
Rate
The frequency of demographic events in a population during a specified time period divided by the population "at risk" of the event occurring.
Ratio
The relation of one population subgroup to the total population or to another subgroup.
Proportion
The relation of a population subgroup to the entire population.
Constant
An unchanging, arbitrary number used to express rates, ratios, or proportions in a more understandable fashion.
Cohort Measure
A statistic that measures events occurring to a group of people sharing a common demographic experience over time.
Period Measure
A statistic that measures events occurring to all or part of a population during one period of time.
Population Composition
The description of a population according to characteristics such as age, sex, race, or other factors.
Vital Statistics
Information obtained from vital events such as births, deaths, marriages, and changes in civil status, recorded in a civil register.
Demographic Indicators
Indicators used to measure changes in health or nutritional status indirectly, indicating direction and speed of change and allowing for comparisons between different areas and groups of people.
Mortality Indicators
Indicators used to measure death rates and signal a broad range of health problems, including crude mortality rate, age-specific mortality rate, infant mortality rate, maternal mortality rate, and under-5 mortality rate.
Morbidity Indicators
Indicators used to measure the frequency of illness, disease, injury, and disability in a population, including incidence and prevalence.1. Disability Rates:The International Classification of Functioning, Disability and Health (ICF) defines disability as an umbrella term for impairments, activity limitations and participation restrictions.
Healthcare Delivery Indicators
Indicators that reflect the equity of distribution of health resources in different parts of the country and provision of health care, such as doctor-population ratio, doctor-bed ratio, and population-bed ratio.
Utilization Rates
Actual coverage expressed as the proportion of people in need of a service who actually receive it in a given period, usually a year.
Social and Mental Health Indicators
Indirect measures like indicators of social and mental pathology are relied upon to assess social and mental health, such as acts of violence, crime, suicide, homicide, road accidents, juvenile delinquency, alcohol and drug abuse, smoking, and consumption of tranquillizers.
Environmental Indicators
Indicators that reflect the quality of physical and biological environment in which diseases occur and in which people live.
Socioeconomic Indicators
Indicators that do not directly measure health but are important in the interpretation of healthcare indicators, such as rate of population increase, per capita GNP, level of unemployment, dependency ratio, literacy rates, family size, housing density, and per capita calorie availability.
Health Policy Indicators
Indicators that reflect the allocation of adequate resources to the health sector and political commitment to health, such as proportion of GNP spent on health services, proportion of GNP spent on health-related activities, and proportion of total health resources devoted to primary health care.
Quality of Life Indicators
Indicators that measure physical, mental, and social well-being as perceived by individuals or groups, including happiness, satisfaction, and gratification in various aspects of life.
Overview of Demographic Changes
A discussion on significant and unprecedented demographic shifts, shaping societies and posing policy challenges, particularly in relation to the global increase in the general population and the aging population in wealthier countries.
Drivers of Demographic Change
Various factors that drive demographic changes, including fertility rates, childhood survival rates, age at death, and migration patterns.
Demographic Transition
A shift from high birth and death rates to low birth and death rates as societies develop, significantly impacting population structures and presenting challenges and opportunities.
Population Pyramid Shapes
Different population pyramid shapes representing high fertility, transitioning, and aging populations, showcasing examples from Nigeria, Bangladesh, and Japan.
Demographic Dividend
A period of low dependency ratio that presents an opportunity for economic growth, depending on effective policies to utilize the working-age population.
Implications for Global Population Distribution
The predicted shift in global population distribution, with Africa and Asia becoming major population hubs, and the understanding that the demographic transition is a temporary phenomenon that will eventually stabilize the global population structure.1. Population Census:A comprehensive enumeration of the inhabitants of a country or specific area, gathering demographic details such as age, sex, marital status, education level, economic activity, migration patterns, and more. Conducted every ten years.
Vital Registration
The mandatory recording of vital events such as births, deaths, marriages, and divorces by every citizen. Contributes to demographic data.
Population Register
A continuous and permanent register containing essential information about each citizen, including names, addresses, age, and sex. Acts as a vital source of demographic data for administrative and legal purposes.
Sample Surveys
Collecting information from a representative subset (sample) of the population rather than the entire populace. Allows for focused data collection on specific aspects of the population.1. Implementation:The process of carrying out a survey, including selecting a representative sample and collecting data using questionnaires.
Surveys
Research method that complements census data by providing more frequent or specialized information, helps verify census accuracy, and allows for efficient and cost-effective gathering of demographic insights.
Population Growth
The increase in the number of people living in the world, with the majority residing in Asia and Africa. Factors such as fertility rates and aging populations affect the rate of population growth.
Demographics
The study of population characteristics, including fertility rates, life expectancy, and age structure. Demographics change over time and vary across different regions.
Population Growth and Development
The relationship between population growth and economic development, where development can lead to smaller families and slower population growth. This has implications for poverty reduction, gender equality, and environmental sustainability.
Development and Smaller Families
Economic development can lead to smaller families through factors such as increased education, urbanization, and access to family planning. Family planning programs play a role in promoting smaller families.
Epidemiology
The field of medical science that investigates the distribution and determinants of diseases within populations. John Snow's investigation during the 1854 cholera outbreak in London is a notable example of the power of data analysis and mapping in understanding and combating epidemics.1. Miasma:A mysterious and harmful vapor believed to come from swamps or the ground, traditionally attributed to causing diseases.
John Snow
Epidemiologist who linked contaminated water from a specific pumping station to a cholera outbreak, challenging prevailing beliefs and revolutionizing disease comprehension.
Ontology
The branch of philosophy that deals with how reality is experienced.
Epistemology
The branch of philosophy that deals with how knowledge is acquired.
Methodology
The methods used for scientific study.
Smallpox eradication
The successful elimination of smallpox through mass vaccination programs and a thorough understanding of herd immunity.
Risk factors
Factors that increase the likelihood of developing a disease, such as smoking for lung cancer.
Disease surveillance
Tracking and analyzing data on disease occurrence and patterns within populations.
Diagnostic tests
Tests used to diagnose diseases, evaluated by epidemiologists for accuracy, sensitivity, and specificity.
Trend analysis
Studying changes in disease occurrence over time or across diverse populations to identify patterns and potential causes.
Epidemiology
The study of the distribution and determinants of health-related states and events in specified populations, with a focus on prevention and control.
Natural history of diseases
The progression of a disease from its initial development to its resolution or chronic state.
Subclinical diseases
Diseases that do not present with noticeable signs or symptoms.
Sporadic
Occasional, isolated cases of a disease that occur infrequently and irregularly in a particular population or area.
Endemic
The constant presence of a disease or infectious agent within a specific population, geographic area, or community.
Hyperendemic
The consistent presence of a disease at a higher than expected level within a specific population over a prolonged period.
Epidemic
A sudden and widespread increase in the number of cases of a disease in a particular population or geographic area, exceeding what is normally expected.
Outbreak
A localized increase in the occurrence of a disease in a particular geographic area, community, or population, larger than what is normally expected.
Pandemic
A global outbreak of a disease, spreading over multiple countries or continents and affecting a large number of people.
Sensitivity
The proportion of true positive results in a diagnostic test, expressed as a percentage.
Specificity
The proportion of true negative results in a diagnostic test, expressed as a percentage.
PPV (Positive Predictive Value)
The proportion of positive test results that are true positives, expressed as a percentage.
NPV (Negative Predictive Value)
The proportion of negative test results that are true negatives, expressed as a percentage.
Vital statistics
The branch of biometry that deals with data and the law of human mortality, morbidity, and demography.
De facto census
Counts people based on where they are during the census, even if they're not usually there.
De jure census
Counts people based on where they officially belong, even if they're not there during the census.
Modern census
A thorough survey that collects detailed information about a country's people, homes, and more.
Sample registration survey
A method of collecting population data through a sample of the population.
Registration of live events
Recording of births, deaths, and other significant events in a population.
Institutional records
Records from institutions such as hospitals or schools that provide data on population characteristics.
Demographic analysis
The study of the components of variation and change in demographic variables and the relationship between them.1. Population Studies:The study of relationships between demographic variables and other variables such as social and economic variables.
Tools of Demography
Count, rate, ratio, proportion, constant, cohort, and period measure.
Health Indicators
Valid, reliable, sensitive, specific, feasible, and relevant measures used to assess health.
Measures of Morbidity
Epidemiological measures used to understand disease distribution and outbreak causes related to food.
Study Types
Ecological study, case series, cross-sectional study, case-control study, cohort study, and interventional study.
Meta-Analysis and Systematic Review
Methods to summarize and interpret multiple studies on a particular topic.
Randomized Controlled Trials (RCTs)
Gold standard for testing the efficacy of interventions.
Evidence-Based Medicine (EBM)
Integrating clinical expertise, patient values, and the best available evidence to make informed decisions about patient care.
PICO Method
A systematic approach to formulating research questions.
Disease Frequency Measures
Incidence and prevalence.
Measures of Association
Relative risk (RR) and odds ratio (OR).
Hypothesis Testing
Statistical tests used to evaluate the significance of observed associations between variables.
Historical Significance and Public Health Impact
Notable contributions and examples of epidemiology's role in public health.
Challenges and Advancements
Impact of technology, ethical concerns, and the evolving nature of epidemiology.
Preventive Medicine
The science and art of preventing diseases, prolonging life, and promoting health.
Public Health
Undertakings for the prevention of diseases and the promotion of health that are primarily a community responsibility.
Objectives of Preventive Medicine
Promoting optimum health and having a physically and mentally sound body.1. Prevent departure from health:Being free from any forms of illness.
Prevent disabling illness after the onset of disease in man
Fixing any forms of disability through rehabilitation.
Primary level prevention
Designed to promote general optimum health or specific protection against disease agents or establishment of barriers against agents in the environment.
Secondary level prevention
Accomplished by early diagnosis, prompt and adequate treatment to prevent the spread of the disease and further complications.
Tertiary level prevention
The level where the defect and disability have been fixed, accomplished by rehabilitation.
Local Infection
Invading microorganisms are confined to one area (e.g., wound).
Focal Infection
Microorganisms are confined to one area, which may serve as a source for further dissemination of toxic materials to other parts of the body (e.g., diarrhea).
Systemic or General Infection
General invasion affecting the entire body (e.g., typhoid fever and cancer).
Bacteremia
Presence of bacteria in the bloodstream but no active multiplication (e.g., Influenza and boils).
Septicemia
Invasion of bacteria in the bloodstream with active multiplication of microorganisms (e.g., typhoid fever caused by contaminated foods and drinks).
Pyemia
Presence of pus-forming bacteria in the bloodstream, characterized by the development of abscesses in various organs (e.g., carcinoma).
Sapremia
A form of blood poisoning caused by toxins produced by certain microorganisms (e.g., canned food poisoning).
Toxemia
Condition of illness due to the presence of toxins in the bloodstream, caused by the ingestion of foods contaminated with toxins (e.g., toxemia of pregnancy due to ingestion of poisonous substances).
Endemic disease
A small number of people are affected among the population of a community (e.g., meningococcal meningitis, common colds).
Epidemic disease
When an endemic disease flares up affecting a large number of people and spreads from person to person within a certain community (e.g., diarrhea, measles, chicken pox).
Pandemic
When an epidemic becomes widespread, and the disease is prevalent throughout the entire country (e.g., blood-borne infections, HIV infection).
Etiologic agents
Rickettsia (microorganisms between bacteria and viruses, respond to antimicrobial agents), Viruses (obligate intracellular parasites).