Demographic Statistics Quiz

Health Statistics and Epidemiology

• Epidemiology is the study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems.
• Epidemiology is derived from Greek words meaning “on or upon, people, and study.”
• It's a scientific discipline that uses systematic approaches, rooted in data.
• It's fundamental to public health and guiding practical public health actions.
• It's used for causal reasoning in public health.

Demography

• Demography is the study of population sizes, composition, and distribution in space.
• Population refers to the number of people in a given place or area at a given time.
• Household is a person or a group of related or unrelated people living in the same dwelling unit, who identify an adult male or female as the head of the household.
• They share housekeeping arrangements and are considered a single unit.

Sources of Demographic Information

• Census is an official and periodic enumeration of population.
• De jure: people assigned to their usual place of residence regardless of current location during the census.
• De facto: people present during the census regardless of usual residence.
• Other sources include sample surveys and registration.

Population Size

• Information on population changes.
• Prioritize and strategize community health programs and interventions.
• Assess possible health related factors.

Measuring Population Changes

• Comparing Crude Birth Rate (CBR) and Crude Death Rate (CDR) .
• Comparison by census data .

Birth Rate

• Average number of live births per 1000 people in a population, in a year.
• Philippines: 22.28
• Japan: 6.95
• United States: 12.28
• Canada: 10.17
• Somalia: 37.98

Death Rate

• Average number of deaths per 1000 people in a year.
• Philippines: 6.41
• Japan: 11.59
• United States: 8.38
• Canada: 8.12
• Somalia: 11.62

Natural Increase

• Difference between the number of live births and deaths in the specified year, in a the specified population.
• NI = Births - Deaths (specified year)

Crude Birth Rate (CBR) Example

• Kidapawan City, North Cotabato, in a given year, had 4567 births; the total population there was 125,447.
• The CBR is 36.4 per 1000

Crude Death Rate (CDR) Example

• Balo-i, Lanao Del Norte, the municipality in a given year, had 5634 deaths, and had a total population of 192,310.
• The CDR is 29.3 per 1000 population.

Rate of Natural Increase (RNI)

• Difference between the Crude Birth Rate and Crude Death Rate (CBR - CDR)

Demographic Indicators

• Population Statistics (sex ratio, dependency ratio, density)
• Vital statistics (BR, DR).

Population Composition

• Sex composition
• Age composition
• Age and sex composition

Sex Ratio

• Number of females to every 1000 males in the population.
• Calculated as: (Number of Females / Number of Males) x 1000

Age Composition

• Arranging ages from lowest to highest to divide the population into two equal groups.
• Identifying the number at the middle point.

Population Distribution

• Urban Rural Distribution- proportion of people living in urban and rural areas.
• Crowding Index- ease of communicable disease transmission by dividing house dwellers in comparison to room numbers
• Population Density- shows how congested a place is, and is related to adequacy of health services.

Vital Health Statistics

• Tabulates, analyses, and interprets data.
• Evaluates data.
• Recommends redirection/strengthening of health program areas.

Rates and Ratio

• Rate- the relationship between events and people exposed in a certain area for the period of time.
• Ratio- describes the relationship of two numerical quantities of events.
• Crude Rate/General Rate- refers to the whole population living in the area.
• Specific Rate- refers to specific population or class group.

Uses of Vital Statistics

• Planning human development
• Dynamics of reproduction
• Life tables
• Risks of dying
• Population growth projections
• Monitoring and evaluating interventions.

Core Epidemiology Function

• Public Health Surveillance
• Field Investigation
• Analytic Studies
• Evaluation
• Linkages
• Policy Development

Public Health Surveillance

• Ongoing, systematic collection, analysis, and interpretation, and use of health data to plan, implement, evaluate public health programs and activities.
• Use of data to monitor health problems to facilitate their control and prevention.
• Health and care providers, clinicians, laboratories, and hospitals report data to the health department.

Field Investigation

• Confirm and clarify details, circumstances, or cases.
• Characterize the extent of epidemics or identify the causes of outbreaks.

Analytic Studies

• Method that is more in depth compared to surveillance and outbreak investigations.
• Uses a comparison group to conduct the analysis.

Evaluation

• Process to determine how relevant, effective, efficient and impactful are the program's activities and results, systematically and objectively.
• Effectiveness- the ability of a program for the intended results.
• Efficacy- the ability to do something under ideal conditions.
• Efficiency- the ability to produce results with minimum resources.

Linkages

• An epidemiologist may be a member or leader during investigations and may work alongside other professionals like laboratorians, sanitarians, infection control personnel, nurses, and other clinical staff.

Policy Development

• Input, testimony, and recommendations are made by public health workers regarding disease control strategies, reportable disease regulations, and healthcare policies.

Descriptive Epidemiology

• Characterizes epidemics in terms of time, place, and person through an extensive characterization.
• Identifies populations at risk of the disease and clues about the cause, source, and mode of transmission for disease prevention and intervention measures.

The W's of Descriptive Epidemiology

• What (health issue): identifying the concern or issue.
• Who (person): identifying the demographics like age, race, sex involved.
• Where (place): pinpointing the locations of interest.
• When (time): determining the period of interest regarding the disease, epidemic, outbreak, etc.

Epidemic Curve

• Analyze disease occurrence from different viewpoints.
• Cholera cases in the Philippines, from March 10 to June 28, 2012.

Epidemic Curve (Time)

• The rate of disease occurrence or the number of cases of disease are presented over time.
• The pattern of disease cases across morbidity weeks.

Place (Geographical Distribution)

• Characteristics of the region, in relation to health issues.
• Clues for diseases in urban areas, economic development, climate type, etc., in comparison with mortality rates.
• Example: Spot map of Chikungunya Cases in Purok III and IV, of Barangay X, City Y, 2012, covering June 4 to August 6

Person (Age, Sex, etc.)

• Distribution of Chikungunya Cases by Age and Sex, in a specific place and time.
• Information about the disease by considering factors like individual characteristics, demographics, socioeconomic status, etc

Person Variables

• Age
• Race/Ethnicity
• Physiologic states (Eg. Pregnancy)
• Immune status
• Marital status
• Tobacco use
• Drug use
• Risk-taking behavior
• Response to social and physical stressors
• Socio-economic status
• Customs
• Knowledge
• Attitude, Practices
• Sex
• Genetic predisposition
• Concurrent disease
• Physical activity
• Dietary practices
• Alcohol use
• Occupation
• Body mass
• Education level
• Occupation
• Religion
• Access to medical services

Disease Morbidity

• Acute Respiratory Tract Infection (Philippines, 2018) – 1,209,821 cases.
• Hypertension (Philippines, 2018) – 602,811 cases.
• Other diseases ranked in terms of cases and rates for 2018 and 2012 in Region 8

Concepts of Public Health Surveillance

• Surveillance is the continuous observation of people, or more, with the intention to direct, supervise, or control.
• By observing the distribution and trends in incidence of diseases, through the systematic collection, consolidation, and evaluation of data on morbidity or mortality, better health problems are addressed.

Surveillance Core Processes

• Capture (early reporting, active, passive)
• Filter (reviewing health events, discarding, substantiating ,within 24 hours)
• Verification (substantiating health events, within 24 hours of capture)
• Assessment (analyze and judge if it's a public-health risk)
• Response (actions and decision)
• Feedback and Dissemination (reporting and health events to stakeholders)

Outbreak or Epidemic

• Occurrence of disease exceeding the expected number over a specific period or area, especially in groups of people.
• Epidemic- involves more people over a wide area.
• Outbreak- localized increase in the incidence of an illness or disease, affecting villages, towns, or closed institutions.
• Sporadic- diseases that happen infrequently and irregularly.
• Endemic: is the steady presence of the illness/disease.
• Cluster- is an aggregation of cases in an area over time, regardless of the number of cases if it exceeds expectations.

Epidemiological Triad

• Agent, Host, Environment

Agent

• Infectious microorganism: a virus, bacterium, parasite, or other microbe.
• Bacteria: Tuberculosis, Salmonellosis, Streptococcal infections
• Viruses: Viral hepatitis A, influenza, viral meningitis
• Mycoses: Ringworm, athlete's foot, candidiasis
• Protozoa: Malaria, Amoebiasis
• Helminths: Schistosomiasis

Host

• Human who contracts the disease.
• Factors like age, sex, race, socioeconomic status, behaviors, lifestyle, sexual behaviors, contraception, nutrient status, immunological and anatomic status

Environment

• Extrinsic factors that affect the agent and opportunity of exposure.
• Physical factors: geology, climate
• Biologic factors: insects
• Socioeconomic factors: crowding, sanitation, availability of health services

Epidemiological Investigation Steps

• Establish disease existence
• Verify diagnosis
• Identify type of reporting format
• Determine if the unusual prevalence of the disease is related to previous experience or nature of the disease.
• Establish time and space relationship
• Define relationship characteristics of community members
• Correlation and conclusion on all data obtained.
• Provision of control measures.
• Other outbreak investigation steps

National Surveillance System

• Philippine Integrated Disease Surveillance and Response System (PIDSR)
• Event-based Surveillance and Response system (ESR)
• Field Health Service Information System (FHSIS)
• National HIV/STI Surveillance and Strategic Information Unit (NHSSS)
• Online National Electronic Injury Surveillance System (ONEISS)
• Philippine Health Statistics (PHS)

Test your knowledge on demographic statistics including the Crude Death Rate (CDR), Rate of Natural Increase (RNI), and sex ratio. This quiz assesses your understanding of important population metrics and their calculations relevant to municipalities in the Philippines.