Module 3 Flashcards
What is epidemiology?
The study of the occurrence or distribution of health-related events, states or processes in specified populations
What is population health?
The health outcomes of a group of individuals including the distribution of such outcomes within the group
What are the health trends bases on ethnicity in NZ?
Life expectancy at birth: 7 years higher for non-maori compared to Maori
Rheumatic Heart Disease Hospitilizations: Higher in Maori than non-maori
COPD Hospitilizations: Higher in Maori than non-maori
What are the health trends based on socioeconomic status in NZ?
Serious skin infection hospitalisations: Increases as NZDep increases
Type 2 diabetes: Cases increases NZDep increases
How do life expectancy and income compare in NZ?
Non-maori in the same income bracket as Maori have a higher life expectancy
What are the patterns of health occurring in NZ?
Non- maori have a higher proportion with lower NZDep and Maori have a higher proportion with high NZDep. Ethnicity and Socioeconomic status are linked factors in health
What is NZDep?
- Area based measure of deprivation
- Areas of approximately 100-200 people
- Deciles: 1=least deprived, 10=most deprived
- Applies to everyone
- Considers a range of aspects
- Can be determined from address
- Not an individual measure
- Doesn’t incorporate all aspects
- Not a label
- Measures relative SES
- Complexity behind the measure
What is absolute poverty?
Income level below which a minimum nutritionally adequate diet plus essential non-food requirements is not affordable. The amount of income a person, family, or group needs to purchase an absolute amount of the basic necessities of life.
What is relative poverty?
The amount of income a person, family, or group needs to purchase a relative amount of basic necessities of life, these basic necessities are identified relative to each society and economy
What is the social gradient?
As deprivation increases, so does the amount of poor health
What are the social determinants of health?
The conditions which people are born, live, grow, work and age, and the wider set of forces and systems shaping the conditions of daily life
What is considered in SES (occupation)?
Non- worker? Classification of job? Changing occupations?
What is considered in SES (Income)?
Gross or net?Individual or Household?
What is considered in SES (Deprivation)?
NZiDep (individual), NZDep (area based)
What is considered in SES (Education)?
Highest qualification? Easy to remember? Relatively stable
What is considered in SES (Living Standards measures)?
Economic Living Standard Index (ELSI) and survey a range of aspects
What was the global burden of disease mortality in 2019?
7.6% injury, 18.1% communicable diseases including group 1, 74.3% non communicable diseases
What happened to the global causes of mortality over time?
Decreased road injuries, increased diabetes, increased Nono-communicable diseases
What are the causes of global mortality by income?
Higher rate of communicable/group 1 in low income, road injuries high for low income, low income has the Big 3 (HIV/AIDS, Tuberculosis and malaria) while high income doesn’t
What are DALY’s (Disability Adjusted Life Years)?
An integrated measure of health loss. It is the sum of years of life lost and years lived with disability adjusted for severity
What is 1 DALY?
Loss of one year of life lived in full health
What do DALY’s measure?
The gap between current health status and ideal health status
What is morbidity?
Any departure from physiological or psychological wellbeing
What are the demographic and epidemiological transition theories?
Two theories that occur together
What does the demographic transition explain?
Changes in population death and birth rates over time, growth and change in populations over time
What is shown in the demographic transition?
Initially, birth and death rates are high with a low population. Death decreases first, population rises, then birth drops and population stabilises
What does the epidemiological transition explain?
Changes in population disease patterns over time, communicable and non-communicable disease
What is shown in the epidemiological transition?
Communicable diseases increases, life expectancy increases and so does the non-communicable diseases
What are the biggest factors in the epidemiological transition?
Sewage, water and also vaccines, antibiotics and healthcare
What is YLL (Years of Life Lost)?
Measure of fatal health loss. It takes into account the number of deaths and the age at death
What is YLD (Years Lived with Disability)?
Measure of non-fatal health loss. Takes into account the number of people in the health state of interest (prevalence/incidence x duration) and the severity of that health state (disability weight)
What is mean by compression of morbidity?
Morbidity occurs later in life:
- slow progression from chronic disease to illness
- will increase milder chronic disease but decrease period of time person experiences a severe disability
- maintain function and improve wellbeing
Where does measuring disease occurrence fit in the public health model?
In the first stage (defining and measuring the problem)
Why do we measure disease occurrence?
To know health status, observe trends and observe how something impacts on different groups
What is the incidence rate?
The rate at which new cases of the outcome of interest occur in a population
What is the formula for incidence rate?
(Number of people who develop the disease in a specified time period)/(Number of person-years at risk of developing the disease)
When do people stop being at risk?
If the becomes case, are lost to follow up or the follow up time ends
What is person time?
The total time people are involved in the study and considered at risk
How to report the incidence rate?
Measure of occurrence, outcome, population, value
What are the limitations of the incidence rate?
Person time may not be available and it is complex to calculate
What is prevalence?
- proportion of the population that have disease at a point in time
- measured to show burden of disease and where resources must be allocated
How to report the prevalence?
Measure of occurrence, exposure or outcome, population, time point, value
What are the limitations of prevalence?
It may be difficult to assess development of disease, is influenced by duration
What is the formula for prevalence?
(number of people with disease at a given point in time)/(Total number of people in the population at that point in time)
What is the relationship between prevalence, incidence and duration?
Changes to incidence and duration can affect disease prevalence (P=IxD)
What is the incidence proportion?
The proportion of an outcome-free population that develops the outcome of interest in a specified time period
What is the formula for incidence?
(number of people who develop the disease in a specified period)/(number of people at risk of developing the disease at the start of the period)
When aren’t people considered at risk?
If they already have the condition or cannot develop it
How to report the incidence proportion?
Measure of occurrence, outcome, population, time period, value
Why do we calculate the incidence proportion?
It gives information about the risk average
What are the limitations of the incidence proportion?
It assumes a closed population without people coming or going, dependent in time period (longer time=higher incidence proportion)
What is age standardisation?
Populations are undermined when age structures differ and disease risk varies with age so age standardisation is used
What is descriptive epidemiology?
Primarily concerned with the distribution of health-related states or events in specified populations (cross sectional and ecological studies). Person, place and time. Observational. Who, what, when, where
What is analytic epidemiology?
Primarily concerned with the determinants of health related states or events in specified populations (cohort, case control and RCT). Associations: exposures and outcomes. Causation. Observational or intervention. Why
What do cross sectional studies measure?
Exposures and/or outcomes at one point in time
What may a point intake be?
A date, event, or time period
What measures of occurrence can cross sectional studies measure?
Prevalence
What can cross sectional studies be used for?
To describe, compare and generate hypothesis, also plan. Hypothesis may be difficult as exposure and outcome are at the same time
What are the limitations of cross sectional studies?
Temporal sequencing (exposure or outcome first), measures prevalence and not incidence, not good for rare outcomes or exposures, not good for assessing variable and transient exposures or outcomes
Why do cross sectional studies?
Can assess multiple exposures and outcomes, depends on your research question, can be inexpensive and quick compared to other study designs
What do ecological studies do?
Compare exposures and outcomes across groups and not individuals
What are ecological studies used for?
To compare between populations, assess population factors and consider hypotheses (but not confirm)
What are the limitations of ecological studies?
Ecological fallacy (ascribing individuals the characteristics of groups), can’t control for confounding and can’t show causation
Why do ecological studies?
Good for population level exposures, good for reviewing (not confirming) hypotheses, data is often routinely collected so may be relatively easy and inexpensive to do, can measure multiple exposures and outcomes
