Module 2 (Lectures 12-18) Flashcards
Step of Public Health Framework
Define Problem, Identify Risk / Protective Factors, Develop / Test Prevention Strategies, Assure Widespread Adoption
Determinants in Individuals
an events that causes a change in health in an individual
Determinants in Populations
includes characteristics of the popl itself
Downstream Interventions
at micro level, treatment systems and disease management
Upstream Interventions
at macro level, govn policies and international trade agreements
Proximal Determinants
‘near’, closely / directly associated with change in health status (eg lifestyle and behavioral factors related to exposure
Distal Determinants
distant in time / place from the change in health status (eg national, political, legal, cultural factors that indirectly influence health by acting on proximal factors)
Dahlgren and Whitehead Level 1 (includes 4 factors)
The Individual, age sex, constitutional factors, individual lifestyle factors
Dahlgren and Whitehead Level 2
Community, social / community networks and living / working conditions
Dahlgren and Whitehead Level 3
Environment, general socioeconomic, cultural and environmental conditions
Structure
social and physical environmental conditions and patterns (social determinants) that influence choices and opportunities
Agency
capacity of individual to act independently and make free choices
Aim of Epidemiology
find cause of disease, by looking at relationship between exposure and outcome (then judge against framework to see if causal)
Bradford Hill Framework Step 1
Temporality
Temporality
first cause then disease
Bradford Hill Framework Step 2
Strength of Association
Strength of Association
stronger association = more likely to be causal in absence of known biases
Bradford Hill Framework Step 3
Consistency of Association
Consistency of Association
replication of findings by different investigators, times, places, methods
Bradford Hill Framework Step 4
Biological Gradient
Biological Gradient
incremental change in disease rates in conjunction with corresponding changes in exposure
Bradford Hill Framework Step 5
Biological Plausibility of Association
Biological Plausibility of Association
does association make sense biologically?
Bradford Hill Framework Step 6
Specificity of Association
Specificity of Association
a cause leads to a single effect or an effect has a single cause. However health issues have multiple interacting causes and many outcomes share causes
Bradford Hill Framework Step 7
Reversibility
Reversibility
demonstration that under controlled conditions, changing exposure causes change in outcome
Bradford Hill Framework Step 8
Judgement
Cause of a Disease
an event, condition, characteristic (or combination) which plays an essential role in producing the disease
Sufficient Cause
‘the whole pie’, sum of all conditions needed for disease to occur
Component Cause
‘each slice’, an individual factor that contributes to a disease, but cannot cause it on its own
Necessary Cause
factor that must be present for disease to occur
Te Pae Mahutonga - 4 key tasks
Mauriora, Waiora, Toiora, Te Oranga
Te Pae Mahutonga - 2 prerequisites
Ngā Manukura, Te Mana Whakahaere
Mauriora
access to Te Ao Māori (the Māori world)
Waiora
environmental protection
Toiora
healthy lifestyles
Te Oranga
participation in society
Ngā Manukura
leadership (health and community)
Te Mana Whakahaere
autonomy (capacity for self governance and community control / enabling political environment)
Importance of preventing disease
limitations of curing disease, increasing cost
Population Health Actions
Health Promotion, Disease Prevention, Health Protection
Population Health Actions - 2 strategies
Population (mass) or high risk (individual)
Population Based (mass) Strategy - focus, aims, useful for, example
whole popl, reduce health risk / improve outcome for all indiv. in popl, common disease / widespread cause, immunisation programs
High Risk (individual) Strategy - focus, advantage, example
individuals perceived as high risk, well tailored to individuals, targeting obese adults
Population Based (mass) Strategy - 3 advantages
addresses underlying causes, large potential benefit, behaviourally appropriate
Population Based (mass) Strategy - 3 disadvantages
small benefit to individuals, little motivation for individuals, whole popl exposed to downsides (less favourable benefit to risk ratio)
High Risk (individual) Strategy - 4 advantages
benefit to individuals, motivation for individuals, cost effective use of resources, good benefit to risk ratio
High Risk (individual) Strategy - 4 disadvantages
cost of screening (need to identify individuals), temporary effect, limited potential, behaviourally inappropriate
Health Promotion
acts on determinants of wellbeing
Alma Act 1978
advocated a health promotion approach to primary care
Ottawa Charter - 3 Basic Strategies
enable, advocate, mediate
Ottawa Charter - 5 Action Areas
Strengthen community action, develop personal skills, create supportive environments, reorient health services, building healthy public policy
Enable
(individual level strategy) provide opportunity for individuals to make healthy choices
Advocate
(systems level strategy) favourable political, economic, social, cultural, physical enviro by promoting health, focusing on achieving equity
Mediate
(joins indiv / groups / systems) opposing interests to compromise for promotion of health
Strengthen community action
getting community to work together to promote health eg soup kitchens
Develop Personal Skills
education (what is healthy) and cooking skills etc
Create Supportive Enviro
physical social enviro, help indiv make healthy choices
Reorient Health Services
focus on supporting needs for healthy lives, help reduce risk factor and enhance protective factors
Building Healthy Public Policy
providing the opportunity for indiv to make healthy choices often through regulations
Disease Prevention
look at particular disease and ways of preventing it eg incidence, prevalence, risk factors, impacts
Primary Disease Prevention
limit occurrence of disease by controlling risk factors
Secondary Disease Prevention
reduce the more serious consequences of a disease, slow the progression
Tertiary Disease Prevention
reduce progress of complications of established disease
Health Protection focus
on environmental hazards (risk assessment, occupational health, risk communication)
Primary Screening
for a risk factor
Secondary Screening
for more serious complications
Tertiary Screening
for complications after clinical diagnosis
Screening Criteria
Suitable disease, test, treatment, screening program
Suitable Disease
common or uncommon but early detection leads to better outcome; knowledge of natural history of disease
Suitable Test
reliable, safe, simple, affordable, acceptable, accurate
Sensitivity
ability to correctly identify those who do have the disease from all indiv with the disease (true positives ÷ all with disease x 100)
Specificity
ability to identify correctly those who do not have the disease from all indiv without the disease (true negatives ÷ all without disease x 100)
Positive Predictive Value (PPV)
probability of having the disease if test positive (true positives ÷ all who test positive x 100)
Negative Predictive Value (NPV)
probability of not having the disease if test negative (true negatives ÷ all who test negative x 100)
Sensitivity and specificity fixed?
yes, fixed characteristic of the test
PPV and NPV fixed?
no, reflect both the test accuracy and prevalence of the disease
if prevalence is moderate / low ____
higher false positive test results
if prevalence is high ____
higher false negative test results
Suitable Treatment
effective, acceptable and accessible
Suitable Screening Program
benefits must outweigh harm, result in reduced mortality or increased survival time
Lead Time Bias
if screening program evaluated in terms of survival time -> false impression. Does it increase survival after point when they would have had clinical diagnosis
Length Time Bias
screening more likely to catch slow progressing disease than fast progressing disease, so will look like survival time is longer than it actually is
Why do we need to prioritize?
not enough money to fund everything
Establishing Population Health Priorities
Evidence based measures (descriptive, explanatory, evaluative), community expectations and values, human rights and social justice
Descriptive Evidence
who is most / least affected? where are we now, come from, going?
Explanatory
what are the determinants / risks?
YLL
years of potential life lost to death
YLD
years lived with a disability
PAR
population attributable risk
Attributable Risk =
Risk Difference (EGO - CGO), amount of ‘extra’ disease attributable to a particular risk factor in EG
Population Attributable Risk (definition)
amount of ‘extra’ disease attributable to a particular risk factor in a particular population
Population Attributable Risk (formula)
occurrence in total popl (PGO) - occurrence in unexposed popl (CGO)
(all positive outcomes ÷ total popl) - (positive outcome for CG ÷ CG)
Evaluative Evidence
is the intervention improving health outcomes? how well can problem be solved? economic feasibility
Community Expectations / Values and Human rights / Social Justice
will it be accepted? what do communities want?
