Lecture 11 + 12 + 17 + 18

Question 1

Explain the cause of the problem.

Answer 1

Identifying the likely cause of the disease is in population is what epidemiology is all about.
1. Establishing causal relationships is important to provide support for evidence-based practice
2. Epidemiology does not determine the cause of a disease in an individual
3. Sometimes, preventive measures can be put in place before we determine the cause of a disease

Question 2

What is the Bradford Hill Framework? (1965) “Aid to thought”.

Answer 2

There is a 7 points of criteria to see whether the association of the exposure and outcome is casual.
1. Temporality
2. Strength of association
3. Reversibility
4. Biological gradient (dose-response)
5. Biological plausibility of association
6. Consistency of association
7. Specificity of association

Question 3

Explain the criteria for temporality, strength of association and reversibility.

Answer 3

Temporality = First the cause then the disease and essential to establish a causal relation.
Strength of association = The stronger an association, the more likely to be causal in absence of known biases (selection, information, and confounding). This means that if we ruled out the biases, the link between smoking and lung cancer would be more believable.
Reversibility = When the exposure / risk factor is removed, the outcome should be impacted (reduced).

Question 4

Do all Bradford Hill criteria must be fulfilled to determine causality.

Answer 4

No

Question 5

Explain biological gradient (dose response) and Biological plausibility of association.

Answer 5

Biological gradient = Incremental change in disease rates in conjunction
with corresponding changes in exposure. This means the more amount of exposure, the higher rate of disease outcome you will get. Think of it like a positive, linear gradient! Example: Someone smokes 1 cigarette a day → low risk of lung cancer, but someone smokes 30 cigarettes a day → high risk
Biological plausibility of association = Does the association make sense biologically?

Question 6

Explain consistency of association and specificity of association.

Answer 6

Consistency of association = Replication of the findings by different investigators, at different
times, in different places, with different methods. Example = Multiple studies have shown similar results
Specificity of association
o A cause leads to a single effect
Many disease share causes
Smoking Lung cancer, CVD, other respiratory disease etc.
o An effect has a single cause
Disease have multiple causes
Lung cancer is caused by smoking, exposure to asbestos etc

Question 7

Define epidemiological triad and what does it show.

Answer 7

Epidemiological triad is a framework that shows that multiple factors interact to cause a dis-ease in a population. It shows us that causal phenomena are usually complex and
exposure-outcome relationships are usually not 1:1.

Question 8

Explain the epidemiological triad.

Answer 8

There are three main factors:
1. Host = Who gets the disease? It is smokers or non-smokers?
2. Agent = What causes the disease? It is a Biological, Nutritional,
Physical, Chemical factor?
3. Environment = What external factors allow it to happen? Physical, Social, Policy

Question 9

Define cause of disease

Answer 9

An event, condition, characteristic (or combination
of these factors) which play an essential role in
producing the disease

Question 10

Describe the sufficient cause pie from the KJ Rothman, 1986) casual pie model.

Answer 10

1. Sufficient cause pie is the ENTIRE pie. Without any of the component that make up the sufficient pie, the disease would NOT occur. A disease may have several sufficient cause pies because several pies can produce the same disease.

Question 11

Describe the component cause pie from the KJ Rothman, 1986) casual pie model.

Answer 11

Component cause are the several factors that make up the sufficient pie. A factor that contributes towards dis-ease causation, but is not sufficient to cause dis-ease on it’s own
* Component causes “interact” to produce disease.

Question 12

Describe the necessary cause pie from the KJ Rothman, 1986) casual pie model.

Answer 12

A factor (or component cause) that must be present for a specific dis-ease to occur. However, it may not cause the disease own its own. EXAMPLE: The bacteria Mycobacterium tuberculosis is a necessary cause of tuberculosis (TB). If someone does not have this bacterium, they cannot develop TB, but having the bacterium alone doesn’t guarantee they will get the disease. Sometimes, a necessary cause will be a component cause.

Question 13

List some points that are TRUE for the casual pie model.

Answer 13

1. You do not need to know every component cause to prevent cases of the diseases.
2. Blocking/removing any component cause would result may reduce the risk, but cases may still occur.
3. Knowledge of the complete pathway is not a pre-requisite for
   introducing preventive measures
4. Can intervene at any number of points in the pie

Question 14

What are preventative measures?

Answer 14

Preventative measures mean action to reduce the risk of the disease. E.g: vaccinations, wearing sunscreen to prevent skin cancer.

Question 15

What does causality mean and whats the difference between causality and association?

Answer 15

It means the exposure directly causes the outcome. Association occurs when the exposure and outcome are linked.

Question 16

Why can’t we prove causality in human experimental studies?

Answer 16

Because of ethical and practical reasons. We can’t expose harmful things to people because that is unethical and people live in noisy environments where all other factors also contribute to their health.

Question 17

Describe the key features of epidemiological study?

Answer 17

Most epidemiological studies,
o are non-experimental
o are conducted in ’noisy’ environments in free-living populations
o determine the relationship or association between a given exposure to a cause/s and dis-ease outcome in populations
Epidemiology can also show the statistical association between a potential exposure and outcome.

Question 18

What does Statistical exposure mean?

Answer 18

Two things are linked — when one changes, the other often changes too.

Question 19

Does this mean the exposure causes the outcome?

Answer 19

Sometimes, but not always.

Question 20

What do you need to do when to look for links between Exposure &
Outcome

Answer 20

1.Need sufficient studies done in diverse settings
and adequately limiting random errors, non-random errors (bias) and confounding
2. Judge findings against a framework to see if the association is causal

Question 21

What does causes of the causes mean for individuals vs populations?

Answer 21

For individuals: “any event, characteristic or other
definable entity, that brings about a change for better or worse in health. Causes of the causes relates to why it drives people to smoke in the first place. For populations it depends on the characteristics and context in which the population exists.

Question 22

What are downstream and upstream interventions?

Answer 22

Downstream interventions are operate at the micro (proximal) level,
including treatment systems, and disease management. It’s all about the direct actions to deals with management of health issues. Upstream interventions are operate at the macro (distal) level, such as
government policies and international trade agreements. It focuses on the broader factors.

Question 23

Explain Proximal and Distal determinants (causes of causes) which are DIFFERENT to interventions.

Answer 23

Proximal Determinants:
A determinant of health that is proximate or near to the change in health status; ‘near’ generally refers to any determinant that is readily and directly associated with the change in health status. E.g. lifestyles and behavioural factors related to nutrition or smoking or other exposures.
Distal Determinants:
A determinant of health that is either distant in time and/or place from the change in health
status.
Distal determinants of health are also referred to as ‘upstream factors’. E.g. national, political and legal factors.

Question 24

What is another name for distal determinant?

Answer 24

Upstream factors.

Question 25

Describe the level 1 individual of the The Dahlgren and Whitehead Model. This is the very inner CIRCLE.

Answer 25

These are the non-modifiable factors that you cannot change such as age, sex and genes/ biology. Example: Single gene disorders only affect individual level because it only changes one gene of a human. Polygenic inheritance = influences likelihood of offspring developing a disease, therefore impacting population.

Question 26

Describe the lifestyle factors.

Answer 26

The importance of food, exercise, and risky behaviours in relation to health outcomes. – Remember the social gradient * The choices you make as an individual impact on the likelihood that you will have good(or bad) health * Habitus: lifestyle, values, dispositions and expectation of particular social groups ‘learned’ through everyday activities

Question 27

What is the social gradient?

Answer 27

The social gradient is a concept that explains how health outcomes tend to improve as you move up the socioeconomic ladder (i.e., as you have more wealth, education, and social status) and worsen as you move down.

Question 28

Describe level 2 of the model.

Answer 28

Social and community networks & Living and working conditions * Families and friends play a significant role in developing ‘normative’ behaviours * Attitudes and behaviours of people living and working in the local community influences the sense of what is normal and acceptable * Social capital - the value of social networks that facilitates bonds between similar groups of people – provides an inclusive environment for people from diverse backgrounds – Civic participation, volunteerism, supportive communities “it’s not what you know, but who you know”!

Question 29

Name the 6 environments for level 3 of the general socioeconomic, cultural and environmental conditions

Answer 29

1. Physical 2. Built (buildings) 3. Cultural 4. Biological 5. Ecosystem 6. Political

Question 30

Explain the The Current Living Standards Framework and the key 3 aspects to it.

Answer 30

This framework is hat measures the overall well-being and living standards of New Zealanders. There are 3 aspects: our individual and collective wellbeing (resources and aspects of our lives that are important for the wellbeing of individuals, families, whānau and communities). Then there is institutions and governments (role our institutions play in safeguarding and building our wealth, as well as facilitating the wellbeing of individuals and collectives). Lastly, there is the wealth of NZ which is how wealthy we are in aggregate as a country, including sources of wealth not fully captured in the system of national accounts: human capability and the natural environment.)

Question 31

What are the four capitals from the wealth of NZ?

Answer 31

1. Social capital that describes the norms and values. Examples: trust, rule of law, crown - Maori relationship, cultural identity, and connections between people and communities. 2. Financial capital : Houses, roads and buildings. 3. Human capital: People's skills, knowledge, physical and mental health. 4. Natural environment: Land, soil, water, plants animals, minerals and energy sources.

Question 32

Define structure and agency.

Answer 32

Social and physical environmental conditions/patterns (social determinants) that influence choices and opportunities available. Structure shapes or limits what people can do. Agency – the capacity of an individual to act independently and make free choices Agency is what people choose to do within those limits.

Question 33

What does agency and structure represent on the Dahlgren and Whitehead Model.

Answer 33

Agency= Individual lifestyle factor + social and community networks. Structure= Social community and general socio-economic, cultural and environmental factors.

Question 34

What are some key health indicators showing inequity for Māori?

Answer 34

Life expectancy, cancer rates, asthma, chronic illness – Māori fare worse on all.

Question 35

Describe the nature and extent of inequities in health between Māori and non-Māori

Answer 35

Inequities come from systems, not individuals. 3 Drivers of Ethnic Health Inequities (Camara Jones, 2001): Access to health determinants (e.g., housing, income) Access to care Quality of care

Question 36

Identify an example of an historical process influencing current Māori health

Answer 36

Colonisation brought: Land loss Breakdown of Māori political structures Imposition of colonial values (e.g., “civilised” land use) Te Tiriti was undermined: Māori authority not recognised Policies created by and for settlers Long-term impact: poverty, social disruption, reduced power.

Question 37

Give an example of how social and economic inequities have arisen

Answer 37

Land alienation → economic deprivation Unequal citizenship: e.g., pension access was harder for Māori Modern example: Bowel screening policy Māori at higher risk younger System delayed equity-focused change Result: Entrenched poverty, social frustration, victim blaming

Question 38

What’s the difference between equality and equity in Māori health?

Answer 38

Equality treats everyone the same; equity ensures fairness based on need.

Question 39

Why do we need to see population data?

Answer 39

It helps measures trends in Births * Mortality (deaths) (all-cause, cause-specific) * Morbidity (illness) (general, specific condition) * Migration AND Unemployment / benefit claimants / pensions * Crime (broad & detailed classes of offence) * Health service utilisation (where to provide services, and who uses them * Voter turnout, political party voted for * Education pathways

Question 40

What is the difference between sex and gender?

Answer 40

Sex is male or female and gender is behavioural.

Question 41

Explain the difference of population structure and population composition.

Answer 41

Population structure shows the entire population by age & sex and population composition shows other attributes.

Question 42

What is the main population data sources for epidemiology and explain it.

Answer 42

A group of people were hired (called enumeration officers) to collect data that told us the complete count of the population in NZ and gave us important data on age, sex, ethnicity and more. Census forms were delivered in each household, and then collect they were filled out. **Meshblock** is a term used to describe the smaller georgrpahical unit (small areas) and it contains 100 people. Meshblock helps manage the count of the entire people in NZ. In 2018, the census forms will meant to complete online. It was good as it reduced face to face interaction but there were lower response rates from people.

Question 43

What is IDI?

Answer 43

IDI is a data base uses routinely collected information from many government (and some other agencies) * All information is de-identified and strict rules are in place to preserve confidentiality * Data from many sources can be linked to create a population based * To be ‘counted’ you have to have had an interaction with one or more of these agencies – i.e. health, education, tax, police, social development, ACC – An activity-based population

Question 44

What is an activity based population?

Answer 44

You will only be counted in the data if you interact with a government agency. To be counted, you must have: Visited a hospital, filed taxes, received a benefit, police, ACC (injury claim)

Question 45

What are events that determine population structure?

Answer 45

Age-sex structure is a function of previous patterns / trends of fertility, migration & mortality events. Fertility, mortality and migration are not evenly distributed across the population by age and sex * Fertility: women only, concentrated in young adult ages * Mortality: highest among the very young and the elderly * Migration: varies with sex and stage in the life cycle

Question 46

What is the dependency ratio?

Answer 46

The dependency ratio measures how many young and elderly people rely on the working-age population (ages 15-64) for support.

Question 47

What is the difference between structural and numerical ageing?

Answer 47

Structural ageing is the increase in the proportion of the population that is elderly and numerical ageing is the absolute increase in the population that is elderly.

Question 48

What is natural and absolute decline of population.

Answer 48

It shows how ageing can have significant impacts on the population. Natural decline of the population: occurs when there are more deaths than births in a population and Absolute decline of the population: occurs when there is insufficient migration to replace the ‘lost’ births and increased deaths.

Question 49

Where is NZ in the demographic stage?

Answer 49

New Zealand is currently in stage 4 of the Demographic transition, characterized by low mortality and low fertility rates.

Question 50

What is prioritised output and describes the advantages and disadvantages?

Answer 50

Prioritised output = One person, one ethnicity (chosen by priority), even if they identify with multiple groups. Helps ensure visibility of ethnic groups that are smaller or of policy importance (like Māori and Pacific peoples). Simplifies data: Each person appears only once, which makes datasets easier to work with. Biased representation: Some ethnic groups can be over-represented, while others may be under-represented or excluded. The total of all ethnic groups will not equal the total NZ population if people identify with multiple ethnicities — this is FALSE in prioritised output. It's externally applied, meaning it goes against the idea of self-identification, which is central to ethnicity data collection.

Question 51

Which of these is true about prioritised output?

Answer 51

Ensure that where some need exists to assign people to a single ethnic group, ethnic groups of policy importance or of small size, are not swamped by the NZ European ethnic group The sum of the ethnic group populations will add up to the total NZ population There may be mis-representation of some ethnic groups at the expense of the others