Module 4 Flashcards
Prioritisation in population health
- priority = maximum benefit for maximum number of people
- health resources are finite
- prioritisation has opportunity cost (some people will lose out)
- individual vs population needs resourcing
- ethical + evidence based judgement
- difficult comparing outcomes (apples vs oranges)
Reasons for GBD Project
- incomplete data from many countries
- available data focused on deaths, barely anything on non-fatal outcomes
- lobby groups give distorted images of importance of problems
- 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’
Aims of GBD Project
-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 as well as non-fatal outcomes (i.e. disability) when estimating the burden of disease
DALYs
- DALYs: disability adjusted life years
- summary measure that combines data on premature death and non-fatal health outcomes to represent the health of a particular population as a single number
- considers premature mortality (before life expectancy of country) and non fatal health outcomes (disability)
- uses YLD (years lived with disability) and YLL (years of life lost)
- year with disability is based on disability weight of outcome
- YLD represents morbidity, YLL represents mortality
Enables comparison between diseases to:
- prioritise health interventions
- monitor health interventions
- assess changes of disease burden over time
YLL and YLD: data needed
YLL
- number of deaths from the disease in a year
- years lost per death relative to an ideal age
YLD
-number of cases with non-fatal outcome with the disease
-average duration of non-fatal outcome until recovery / death
-disability weight (e.g. lung cancer - 0.29)
→weight is anchored on a disability scale of 0 - 1, 1 is death and 0 is full health
→panel of experts have argued and come up with this scale
GBD disease grouping
Group 1: Communicable disease (infectious) and perinatal conditions (early life)
Group 2: Non-communicable disease (chronic)
Group 3: Injuries
NZ DALYs trend
-mainly non-communicable disease with some injuries there
Overall global DALYs trend
- communicable diseases coming down except HIV
- non communicable diseases increasing overall
- injuries increasing overall
- mental health was something not picked up before by fatalities (GBD discovered this as it looks as non fatal outcomes)
- GBD also identified injury as a key issue
DALYs high income vs low income countries
- high income countries - most deaths over age of 80 years
- sub-saharan Africa - barely surviving to their 5th birthday - GBD captures not just number of deaths but when - young people dying (particularly in low income countries) contributes many YLL and a lot to DALY burden
- helps us direct interventions to prevent this happening
- low income: lots of group 1, lots of group 2
- middle income: all groups mixed
- high income: mainly group 2, little group 1
- same amount of injury in all incomes
Gains of DALYs
- 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)
Challenges of DALYs
- who should decide disability weights? → global panel is contentious issue
- reasonability of applying one set of disability weights globally due to differing legislation and support service strength in countries
- how does physical and social environment influence disability experiences
2 Major ones
- disability weights do not vary with a persons social position, where they live, access to health care, or other life circumstances
- GBD project criticised for potential to represent people with disabilities as a burden → medical model
Models of Disability
Social model
- disability is a social issue caused by policies, practices, attitudes or the environment
- focuses on ridding society of barriers rather than curing
Medical model
- disabled people defined by illness or condition
- focus on curing, individual problem, dependency
HIV: trends
- communicable and perinatal conditions gone down
- HIV/AIDS ranking gone up from 1990-2019 in YLL, YLD and DALYs
- does not follow epidemiological transition
- heterosexual transmission is dominannt mode
- 95% were in low and middle income countries
- of new infections among people 15 or older, around 39% are people aged 15-24 (mainly female in Sub-saharan Africa)
- low access to treatment is especially marked in low and middle income countries
- only a minority (36%) treated in Western and Central Africa
- majority treated in Europe and America (around 70%)
- number of people living with HIV continues to rise due to life-prolonging treatment (less deaths)
HIV: background
- celebrity status
- most people affected → celebrities in Europe and America → brought it to agenda of public health specialists
- attatched to discrimination and stigma
- a lot of children got the disease got it from their parents, and lost their parents to the disease, had to live with the stigma of HIV/Aids
- we know have better forms of treatment and testing, people are not dying as much as when the disease was previously emerging
HIV: demands from public health epidemiologists
- human rights and fears (different perspectives and situations)
- screening (in the absence of a known agent and test)
- request for definitive evidence
- costs for screening versus numbers to save