Long-term changes and transitions in population health



Long-term / secular trends
•Very long or dramatic changes are often call “transition”
–Demographic transition
–Mortality transition
–Epidemiological transition
–Health transition
–Nutrition transition
–Societal transitions
–…
•Often over-simplifications but important concepts

Crude death rates, US, 1900-1997
Ausubel, Meyer & Wernick, 2001


Mortality transition (England & Wales)



National population projections, UK, 2014
Image result for crude mortality england and wales


Selected diseases as fraction of all deaths



Selected diseases as fraction of all deaths



Eight killers (% of all deaths)
Ausubel, Meyer & Wernick, 2001


Cardiovascular diseases and cancers (% of all deaths)
Ausubel, Meyer & Wernick, 2001


Demographic transition
Image result


Image result for epidemiological transition model



Image result for epidemiological transition model



Stages of demographic, health and nutrition change



Stages of the nutrition transition
Popkin, PHN 2002


Question:
Does longer / better life make people happier?


Social forces and health transitions
•Similar to “causes of the causes”, social forces have major impact on long-term transitions
•Transitions may be accelerated
•Double burden of communicable and non-communicable diseases in many low income countries may
reflect accelerated epidemiological transition (caused by social and economic developments)
Understanding Human Happiness and Well Being

Figure 1 from Kahneman, D., & Deaton, A. (2010). High income improves evaluation of life but not
emotional well-being. Proceedings of the National Academy of Sciences, 107(38), 16489-16493.


Figure 1 and 2 from Killingsworth, M. A. (2021). Experienced well-being rises with income, even
above $75,000 per year. Proceedings of the National Academy of Sciences, 118(4).


Mortality & morbidity compression



Mortality / morbidity compression
•Concepts closely related to demographic and epidemiological transitions
•Also related to population ageing
•Mortality compression (“rectangularisation”)
–It is important how long people live (assuming a maximum biological limit to life span)
•Morbidity compression
–As people age, they develop a range of illnesses and disabilities
–It is important how long people live in good health
•
•

Long term changes in survival
SAGE Books - Ageing in Society: European Perspectives on Gerontology


Rectangularisation
(pulling the survival curve to the upper right corner)
Looking Good, Feeling Better | Vitamin D Deficiency Survivor

Morbidity compresson
Pulling the disability-free survival to the upper right corner


https://fanaticcook.files.wordpress.com/2015/01/compressionofmorbiditycurve.jpg



Squaring the Curve of Cardiovascular Health From the Beginning of Life | American Academy of
Pediatrics


Compression of morbidity scenarios
Compression of Morbidity Theory


Morbidity compression
•Is it happening?
•Evidence is inconsistent
–Some studies suggest life extension but no morbidity compression (living longer but also longer
with disability)
–Some studies suggest relative compression (shift to the right)
–Some studies suggest absolute compression
–Depending on definition of “morbidity” / “disability”
–

Summary
•Secular trends = long-term changes
•Demographic transition (centuries)
–Mortality & fertility changes
•Epidemiological transition
–Reflects risk factors, different types of diseases
•Morbidity compression
–Related to population ageing, improvements in health, clinical care, technology
•