Lecture 16 - Chronic disease and old age

The UN estimates the world population will stop at around _____.

UN estimates population will stop at around 11-12 billion.

What is occurring to birth rates in developed countries around the world?

Many developed countries have a birth rate below the replacement rate 

• Potentially may lead to population decline globally as fewer and fewer people have babies  

Why can world population keep rising even as fertility falls?

Population momentum  

• Build-up of older people which means that although fewer babies are born the population still grows 

• As the older individuals die, the population may begin to collapse  

What factors impact outcome in old age?

• Genes 

  • Only contribute about 20% to outcome in old age 

• Nutrition  

• Lifestyle 

• Environment  

• Attitude 

• Mental health 

• Socioeconomic status 

What are the three types of aging?

Biological aging

Phenotypic aging

Functional aging

What is biological aging?

• Molecular damage

• Defective repair

• Energy exhaustion

What is phenotypic aging?

• Body composition

• Energetics

• Brain health

• Gait

What is functional aging?

• Physical function

• Cognitive decline

• Mood

• Mental health

What did the ‘Newcastle 85 study’ find about disease frequency in 85 year olds?

Found 85 year olds had less diseases than expected  

• Overall around 3-5 diseases per person  

Disability was also rather lower than expected  

• Many of them had very little difficulty with daily activities  

What were the common diseases and impairments in the 85 year olds studied?

• Hypertension  

• Arthritis  

• Hearing impairments  

What is life expectancy?

The average number of years a person is expected to live

• Key indicator of public health

Why is life expectancy not enough sometimes?

Quantity of older people is not enough 

• Need a strong measure of quality of life 

• If people live for a long time but are extremely unhealthy for many years than that’s bad

How can life expectancy be broken down?

Life expectancy can be broken down into healthy years and unhealthy years 

• Can the measure how healthy a population is

• Goal is to maintain healthy for longer, leading to more years lived healthy and independent  

  • People want to live a long time and die quickly

Measuring aging through the difficulty of daily activities is called what?

Known as hierarchy of disability 

• As we age we experience age-related functional decline 

• Difficulty with daily activities unfolds in an order, e.g:

  • Cutting toenails and shopping

  • Heavy housework and cooking

  • Dressing and feeding

What is the pessimist theory of morbidity?

Increases in life expectancy causes years of sickness to increase 

• Driven by life saving tech not curative tech  

What is the dynamic equilibrium theory of morbidity?

Years of sickness stable

• But less severe disability

• Driven by disease management and slower progression

What is the optimist theory of morbidity?

Years of sickness decreases  

• Driven by lifestyle changes and prevention of disease

What did the MRC CFAS I study aim to do?

Study aimed at investigating dementia  

• Epidemiology of Alzheimer’s disease 

  • Most common form of dementia 

  • No known cure 

  • Progressive disease with the earliest symptoms being memory loss 

    • However makes early diagnosis difficult  

What did the MRC CFAS, dementia study, find?

Relationship with age 

• More women suffer than men 

• Over time saw a compression of cogitative morbidity  

• However, north/south divide can be seen 

  • Live expectancy and disease free live expectancy are both lower in the North

What is the Population Ageing and Care Simulation (PACSim)?

Uses real data from individuals in English ageing cohort studies 

• Artificially ages them in a stochastic framework 

Purpose is to estimate the prevalence of ill-health and the numbers who may require long-term care 

What are the four intervals of need?

High

• Bedbound/chair-bound

• Unable to use toilet without help

• Need help feeding

Medium

• Need help preparing a meal

Low

• Need help to wash all over or bath or shop

Independent

How has dependency at 65 changed for men?

Life expectancy has gone up and so has independent life expectancy  

How has dependency at 65 changed for women?

Life expectancy has gone up but independent life expectancy has remained stable