1.0 Demography and Populations

Question 1

What is demography?

Answer 1

Study of age structure and growth of population<br></br>Encompasses current <b>stock</b> and <b>flow</b>

Question 2

What is stock?

Answer 2

The age and sex structure of a population

Question 3

What is flow?

Answer 3

Flow of vital events<br></br>Birth/death/migrations<br></br>Usually summerised using rates or expectancy (e.g. life expectancy)

Question 4

What is a rate? (true rate)

Answer 4

Frequency of an event occurring per person time<br></br>(number of x per 1000 people over a given period[year])<br></br><br></br>E.g. 10.6 deaths per 1000 person years

Question 5

What is a risk?

Answer 5

Probability of a specified event occurring within a specified period

Question 6

Define crude birth rate:

Answer 6

Number of births per unit of person time

Question 7

Define crude death rate:

Answer 7

Number of deaths per unit of person time

Question 8

Define crude rate of national increase (or decrease):

Answer 8

Crude birth rate - crude death rate

Question 9

What is the usual range given to reproductive life?

Answer 9

15-45yrs old

Question 10

What is the total fertility rate?

Answer 10

<b>Total number of babies born per average reproductive lifetime</b><br></br><br></br>Sum of probabilities of giving birth in each year of reproductive life (15-45yrs)<br></br><br></br>In UK this is ~ 2

Question 11

What is gross reproductive rate?

Answer 11

<b>Total number of daughters per average reproductive lifetime</b><br></br><br></br>Proportion of female births x total fertility rate

Question 12

What is net reproductive rate?

Answer 12

Average number of daughters per mother who are expected to survive to reproductive age

Question 13

Define infant mortality ‘rate’:

Answer 13

“Probability of dying before 1st birthday<div><br></br></div><div><img></img></div>”

Question 14

Define child (under 5) mortality ‘rate’:

Answer 14

Probability of child dying before 5yrs old.<br></br><br></br>Done by asking:<br></br>1) How many births have you had?<br></br>2) How many are still alive?

Question 15

Define adult mortality ‘rate’:

Answer 15

Probability of dying between ages of 15 and 60

Question 16

Why is it important to age standardise birth and death rates?

Answer 16

Because values are sensitive to age structure (esp. death rate)<br></br><br></br>Death rates within each age group could be lower in population A compared to population B. Crude death rate could, however be the same if population A has a more ageing population

Question 17

What is q(x)?

Answer 17

Probability of dying during age interval<br></br>(this info is given to us)

Question 18

What is l(x)?

Answer 18

Number living at beginning of interval<br></br><br></br>l(x+1) = l(x) - d(x)

Question 19

What is d(x)?

Answer 19

Number of deaths during interval<br></br><br></br>d(x) = l(x)*q(x)

Question 20

What is L(x)?

Answer 20

Number of person-years of life lived in this age intervals<br></br>L(x) = l(x+1) + 0.5*d(x)

Question 21

What is T(x)?

Answer 21

Number of person-years of life lived in this and all subsequent age interval<br></br><br></br>T(x) = L(x) + from x to final row

Question 22

What is e(x)?

Answer 22

Life expectancy at beginning of interval<br></br><br></br>e(x) = T(x) / l(x)

Question 23

Why is it better to separate childhood and adult mortality?

Answer 23

Because there is limited association between child and adult mortality risks

Question 24

When were biggest gains achieved for childhood mortality?

Answer 24

Early 20th century<br></br><br></br>Child mortality reduce by 50% in the first 3 decades of 20th century (1900-1930)

Question 25

When were biggest gains achieved for adult mortality?

Answer 25

Late 20th century

Question 26

What are possible explanations for these changes in mortality?

Answer 26

“<b>1) Better food</b><br></br>Increased incomes led to better nutrition (this wasn’t as much the case in the UK, but other European countries saw poor people suffer when food prices went up due to poor harvest)<br></br><br></br><b>2) Professional medicine</b><br></br>Played little role in reducing mortality<br></br><br></br><b>3) Advancement and Diffusion of useful knowledge</b><br></br>"”Domestic medicine”“<br></br>Better understanding of how to protect and restore health”

Question 27

What was the link between social class and mortalilty in the 20th century?

Answer 27

There was a weak link between social rank and child survival.<br></br><br></br>When data was adjusted for environment - it seemed that the only benefit was living in a safer area-

Question 28

What scientific knowledge has become public health agendas to improve childhood mortality?

Answer 28

<b>1) Cleanliness</b><br></br>Breast milk, boil cows milk, control flies, wash hands, keep infected people away from children<br></br><br></br><b>2) Mass participation</b><br></br>Books used to disseminate into<br></br>Newspapers<br></br>Baby weeks in local communities<br></br><br></br><b>3) Increased role of the mother figure</b>

Question 29

What two improvements played a big role in improvement of adult mortality?

Answer 29

<b>1) Decline in Tb</b><br></br>- Improvements were seen well before the vaccine was developed<br></br><br></br><b>2) Decline in tobacco caused disease</b><br></br>- Responsible for 3/4 decline in total risk<br></br>- Tobacco control occurred in late 20th century