Module 4 Flashcards
fundamentals of population/public health
Provide the maximum benefit for the largest number of people
need for priorities
- Health resources are finite (limited)
- Each prioritisation has an opportunity cost
- Rationing involves ethical (what communities want/need) as well as evidence-based judgement
- difficult to compare outcomes
(can only compare mortality and hospitalisation rates but not all who are diseased (reduced QOL compared to those without) die and some are not able to access/afford hospital care and thus not counted) - Tension between: Individual (clinical services) vs population needs (population health services)
reasons for GBD
- Data (measures of calculating or identifying mortality and hospitalisation data) on the burden of disease (and injury) from many countries were incomplete/limited
- Available data largely focused on deaths
=> little information on non-fatal outcomes (disability) - (Tension between) Lobby groups can give a distorted image of which problems are most important
- Unless the same approach is used to estimate the burden of different conditions, it is difficult to decide which conditions are most important and which strategies may be the “best buys”
Lobby groups
form of advocacy with the intention of influencing decisions made by the government by individuals or more usually lobby groups
- whether a condition is prioritised or not often depended on power of the lobby groups to be able to lobby
GBD reason simplified
needed a way to measure/have a comparable measure to look at health conditions across the board from a global context
aims of GBD
- To use a systematic approach to summarise the burden of diseases and injury at the population-level based on epidemiological principles and best available evidence
- To aid in setting health service and health research priorities
- To aid in identifying disadvantaged groups and targeting of health interventions
To take account of deaths (not just counting the number but also when they happen) as well as non-fatal outcomes (i.e., disability) when estimating the burden of disease
in countries where data is not available…
GBP project identifies a comparable country and then use computational methods to estimate the disease burden in those countries
=> trying to get a real global picture rather than just keeping them out
What GBD looks at
- number of deaths but also WHEN a person dies in relation to life expectancy in a particular country
- non-fatal outcomes (disabilities)
Disability adjusted life years (DALYs)
summary measure of population health that combines data on premature mortality (YLL) and non-fatal health outcomes (YLD) to represent the health of a particular population as a single number which can be used in comparisons between diseases
DALYs enable comparisons between diseases to
- prioritise health interventions
- monitor health interventions
- assess changes of disease burden over time
DALY =
YLD + YLL
YLL
years of life lost
- Represents mortality by counting the years lost due to premature death caused by a disease
(Years lost due to dying before reaching the average life expectancy–ideal age–in a particular country)
YLL =
no. deaths from disease in a year x years lost per death relative to an ‘ideal age’
YLD
years lived with disability
- Represents morbidity by counting the years lived with the disease
YLD datapoints
- no. cases with non-fatal outcome (impairment) from disease
- average duration of non-fatal outcome until recovery/death
- disability weight
disability weight
scale between 0 (full health) and 1 (death)
- GDB Project has a huge team of medical experts that look at possible diseases/disabilities and give each a weight
DALY represents a lost healthy life year
- year in perfect health = 0
- year of life lost due to death = 1
- year with disability = between 0 and 1
cause
reason for death/disability (health outcome)
risk
reason for cause
income
- based on world bank definition
- inequities from a global scale
group 1 conditions
- communicable (infectious) diseases
- perinatal conditions
communicable disease example
diarrhoea, TB, measles, HIV/AIDS, malaria
perinatal conditions example
problems in pregnancy, childbirth, early life
group 2 conditions
- non-communicable diseases (NCDs)
- chronic diseases
NCD example
heart disease, strokes, cancer, diabetes
group 3 conditions
injury
global trends in causes of DALYs
- decreasing perinatal and communicable diseases
- increasing non-communicable diseases (NCDs)
major gains of DALY approach in informing priority setting globally
- Drew attention to previously hidden burden of mental health problems and injuries as major public health problems
- Recognises Non-Communicable Diseases as a major and increasing problem in low- and middle-income countries (not just a rich country problem which is how it was previously thought)
SES trends in causes of DALYs
- high income: higher proportion of NCDs
- low income: higher proportion of perinatal and communicable disease
challenges in using DALYs to quantify burden of disabilities
- who should decide disability weights?
- can disability weights be applied universally?
- lack of consideration of environment
who decides disability weights
GBD uses expert panel: been a contentious issue due to the way they assign weights for different questions
but should the person living with the disability? Their parent or carer? Healthcare provider? Government providing support services? decide?
application of disability weights
Disability weights are considered to be the same as the severity of an impairment relating to a disease/health condition, and do not vary with a person’s social position, where they live, their access to healthcare or any other life circumstance
- Is it reasonable to apply one set of disability weights globally? Do all people with a particular level of ‘disability’ have similar opportunities to be part of society?
(diff. Countries have diff. Govt. support services)
consideration of environment
GBD does not consider social context
- How does the physical and social environment influence disability experiences?
Models of disability
1) medical model
2) social model
medical model of disability
- disabled person is the problem, not society
- disabled people are defined by their illness/medical condition
- Promotes the view of a disabled person as dependent and needing to be cured or cared for (and justifies the way in which disabled people have been systematically excluded from society)
- Control resides firmly with professionals and choice limited to these
social model of disability
- “Disability” is no longer seen as an individual problem but as a social issue caused by policies, practices, attitudes and/or the environment
- focuses on ridding society of barriers, rather than relying on ‘curing’ people who have impairments.
perspective of social model example
e.g person using a wheelchair who cannot access a building => disabled due to absence of ramp NOT their own impairment
climate change => severe weather events =>
- floods
- infection
- hurricanes
indirect effects of climate change
- spread of disease vectors
- agriculture and food supply
- migration
actions against climate change
- planetary diet
- bikes for transport
- better heating
epidemiologic transition
Characteristic shift in common causes of death and disability from perinatal and communicable (infectious) diseases to non-communicable (chronic) diseases
- common causes of death: perinatal/communicable to NCDs
double burden of disease
- experienced by middle income countries
- due to previously common risks for perinatal and communicable diseases co-existing with increasing risks for non-communicable diseases
- major challenges for health policy
factors influencing risk burden
1) strength of causal association between the risk factor and health condition(s)
- e.g relative risk
2) commonness of exposure to risk in the population of interest
- e.g prevalence of risk factor in pop.
PAR (population attributable risk) using DALYs
The amount of “extra” disease or DALYs attributable to a particular risk factor in a particular population
- If the association is causal, this is the amount of the disease burden that we could theoretically prevent if we removed that risk factor from the population.
- DALYs enable comparisons between risk factor
risk transition
changes in risk factor profiles as countries shift from low- to higher income countries, where common risks for perinatal and communicable diseases are replaced by risks for non-communicable diseases
NCD myth: affect mostly high-income countries
reality: >80% of NCDs in LMICs
NCD myth: Affect mostly rich people
reality: Concentrated among poor
NCD myth: LMICs should control infectious diseases first
reality: “Double-burden” requires double-response
NCD myth: Primarily affect old people
reality: Almost half in <70 years (30–69-year-olds)
NCD myth: Chronic diseases can’t be prevented
reality: Significant proportions of premature heart disease, strokes, cancer and diabetes can be prevented
most affected pop. groups
- pop. living in POVERTY
- those living in LMICs
commercial sector (upstream determinant) drives NCD inequities by:
1) shaping preferences and changing social norms
2) actively exploiting difficulties with behaviour change when public health measures place greater emphasis on downstream strategies
1) shaping preferences and changing social norms
Marketing to vulnerable targets
E.g Socioeconomically deprived, women, children (addiction more likely and earlier => lifelong customer)
2) actively exploiting difficulties with behaviour change when public health measures place greater emphasis on downstream strategies
- Frame education as the most effective solution
- Offer choice and pleasure
- Emphasis on moderation
=> puts equity in public health at risk
commercial sector =>
promote unhealthy consumption among vulnerable groups
=> create uneven distribution of risks
=> unequal distribution of NCDs (deprived communities > wealthier communities)
density of outlets that promote unhealthy habits (e.g takeaways, liquor outlets, gaming machines
NOT randomly distributed
- purposely distributed so that there are more in most deprived areas as they bring in greater income
commercial sector is a…
structural driver of NCD inequalities
industrial epidemics
diseases arising from overconsumption of unhealthy commercial products
e.g tobacco, alcohol, processed food, sugar-sweetened beverages
in order to address commercial determinants of NCDs/health inequities
- Shift focus from individual behaviours to broader environment and upstream drivers of unhealthy product consumption
- Tackle the broader determinants of health (i.e. upstream determinants)
- Develop effective health policy recognising the tension between commercial and health objectives
HIV/AIDS was associated with…
a lot of discrimination and stigma
current knowledge of HIV/AIDS
- several modes of transmission
- cheap, reliable, specific screening tests
- caused by virus
- better treatment
not available for HIV/AIDS
- vaccine
- cure
AIDS related deaths are…
decreasing and people are living longer with HIV due to improved treatment and access to treatment/care
Globally, most people living with or at risk for HIV…
do not have access to HIV prevention, treatment and care
high risk groups for unprotected sexual intercourse
- homosexual men sex with HIV+ men
- heterosexual relationships
- sex workers
high risk groups for sharing unsterilized needles
- injecting drug users
- those receiving injections with unsterilised needles (generally in low-resource settings)