MGH4003 – Lectures: New Biology/New Society
Introduction lecture – Anja Krumeich 30/10/2023
There are many connections between non-communicable and infectious diseases.
Model (Slide)
- Biosocial nature of etiology and outcome of global health problems
- One side: what it has to do with your body
- Arrows indicate that what’s going on in the world has an effect on your body
- Viruses, bacteria, genetics, etc.
- A lot of interaction between biological processes and what’s going on in the environment
- What creates/constitutes environment, and how does this influence processes in our bodies
Create a profile of risk and exposures to health
Course: Biology epigenetics social world
Key messages:
1) Health and disease are determined by n ongoing process during which a complex mix of
factors both inside and outside the body interact and synergize in contributing to health and
diseases.
2) Health and disease are contextual. These contexts are the outcome of long historic
geopolitical processes, that interact with local context, impacting health differently across the
globe. Future successful GH professionals will have to have the analytical skills to unravel and
understand these processes.
3) Policy design, promotion of health and prevention and management of diseases efforts
should be grounded in that understanding.
Weeks 1-4 (Coordinator = Pierre Thomas):
- Global burden of disease, changing patterns of disease
- Biological and physical causation mechanisms
- Biomedical sciences innovations (epigenetics, -omic sciences)
Weeks 4-8 (Coordinator = Anja Krumeich):
- Social, cultural, economic and political/historical determinants of health risk and health care
delivery.
Examination (see slide for deadlines, dates are correct, days not)
- Two individual assignments
- One group assignment
Resit = June 15th!
1
,Part 1: New biology
Lecture 1: Burden of Diseases and its transitions – Pierre Thomas 30/10/2023
Burden of disease studies were developed to consistently evaluate the burden of disease globally.
The WHO also compiles similar data in their global health estimates.
By measuring the burden of disease and the trends of this, we also need to define a scope/frame in
which we define this.
- Local bodies/stakeholders that also work with this data: CDC, CBS
Focus of burden of disease studies:
- Death: mortality
- Diseases: morbidity and disability (co-morbidities)
- Risk factors: attribute or exposure that increases the likelihood of developing a disease or
injury (underweight, unsafe sex, tobacco and alcohol consumption, …)
- determinants of health: underlying characteristics that shape the health of individuals and
communities (the social and economic environment)
Global health indicators:
- Proximal: direct measure of health events (deaths, diseases, immunized children attended
delivers, …)
- Distal: indirect measure (education, poverty, sanitation, …) huge effect on health, but not
directly linked to health
- Objective: quantifiable and independent of individual experiences (deaths, diseases, life
expectancy, …)
- Subjective: self-related/perceived health (reported health state, psychological state, …)
- Health expectancy: estimate years of life expected to live healthy (disability free life
expectancy, disability adjusted life expectancy, …)
- Health gaps: provide info on years of healthy life lost (DALY/YLL, …)
Disability adjusted life years/DALY = a measure of overall disease burden, expressed as the cumulative
number of years lost due to ill-health, disability or early death.
- DALY = YLD + YLL
o YLD = Years Lived with Disability definition and quantification of disability (now
based on people’s views, combined with definition of what is the health goal of a
population (the highest observed life expectancy at birth – 82.5/80 years Japanese
women/men)
o YLL = Years of Life Lost
- Better understand the impact of a disease
Incorporation of social value choices (DALY and DALE = disease adjusted life expectancy)
- Definition of what is the health goal of a population (highest observed age, Japan)
- Definition and quanitification of disability (based on people’s views)
Burden of diseases studies
Pros
- Improvements in methodology
- Valuable estimates for comparison and monitoring of health and risks
- Mean to monitor progress towards meeting SDG
- Increasing attempt to include more conditions and risks factors
2
, - Highlight the need for improvements in data collection and management
- Increased transparency
- Include confidence intervals
Cons
- Lack of information
- Low quality data (incomplete/inconsistent)
- Limited spatial resolution (country)
- Limited temporal resolution
- Limited stratification (age, sex)
- Different methodologies for collection and analysis (different reporting and classification of
mortality, diseases and disabilities)
Vizhub.healthdata.org visualize indicators globally (GBD compare)
Transitions models
- See how things have changed over time and how we can make sense of these changes.
- Use metrics/tools to gain a better understanding of what the hell has been happening over
the years.
o Life expectancy
o Child mortality
o Causes of death
1) Communicable, maternal, neonatal, and nutritional diseases
2) Non-communicable diseases
3) Injury
o Excess deaths (e.g. Covid-19)
Major changes in the last 50 years
- Mortality has decreased across all age groups
- For the first time <5 mortality <5 million
- Deaths from communicable diseases largely decreased
- 74% of estimated deaths in 2019 from non-communicable diseases
o Increase in deaths due to ischemic heart disease and diabetes
- Among injuries increase deaths from conflict and terrorism
- Increase levels of obesity
- Increase prevalence of mental health conditions
2015 top 3 mortality: ischaemic heart disease, stroke and lower respiratory infections
2030 top 3 mortality: ischaemic heart disease, stroke and COPD
- Diabetes increases, among others
Progress towards Health-related SDGs
- SDG 3: Good health and well-being
o Ensure healthy lives and promote well-being for all at all ages
The burden of diseases changes
- Change depending on place in the world, and over time. Also, it changes based on which
definitions and categories are used to define it. As well as in exposures determinants risk
factors.
Infectious or communicable diseases
- Infectious diseases = caused by an infectious agent, fungi, virus, etc.
3
, o vCJD
- Communicable diseases = transmission – directly or indirectly – from an infected person
o Measles
- Transmissible diseases = transmission – through unnatural routes – from an infected person
o Tetanus
o Vector in between. If the person next to you was currently suffering from malaria,
you don’t have to be scared, as long as there are no mosquitos.
Categories and definitions of diseases
- Virus involved in pathogenesis of cancers (MS, diabetes?)
- Infections becoming chronic (HIV, HCV)
Changes in the burden of diseases depend on:
- Changes in population demographics demographic transition
o Caused by changes in mortality and fertility rates (SLIDE)
- Changes in type of diseases epidemiologic transition
o The shift in the major causes of death from infectious diseases to chronic and
degenerative diseases associated with a long-term decline in mortality
o More related to non-communicable diseases
o Affected by: demographic changes, socioeconomic development, role of medicine,
changes in risk factors/exposures/determinants, and changes in diseases
classification and emergence of new diseases.
o Theory by Omran (1971) on how the burden of disease changes within countries,
different propositions:
1) Mortality is a central force
2) Shift from infections to non-communicable diseases transition (revisions
slide)
Stages:
The age of pestilence and famine: high mortality is high and low life
expectancy (20-40 years) (up to late 18th century in Western societies)
The age of receding pandemics: improved sanitation mortality declines,
life expectancy up 50 years, exponential population growth
Age of degenerative and man-made diseases: increased SES and lifestyle
mortality declines and life expectancy increases
3) Age and sex differentials
4) Shifts before 20th century associated with rising living standards and
improved nutrition. In 20th century (LICs) with medical progress, organized
healthcare, and mostly international programs
5) Models: mostly based on classical model, but it’s extremely biased (revisions,
slide)
Classical model (most European countries)
Accelerated model (Japan) similar, but mortality started declining later and
faster
Delayed model (Chile, Sri Lanka) mortality decline slowed down
Non-western upper intermediate transition model
Non-western lower intermediate transition mode
Non-western slow transition model
Critiques on epidemiological transition
- Non clear beginning and end of transition
- Not unidirectional and uninterrupted progression
4