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DEN2025 - Dental Public Health and Behavioural Science > Vital Statistics > Flashcards

Flashcards in Vital Statistics Deck (43)
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1
Q

What do rates tell?

A

How common it is for a given event to occur

2
Q

What are crude rates?

A

Rates computed for an entire population

3
Q

What are specific rates?

A

Rates computed for a subgroup of the population

4
Q

Describe the worded calculation of rates

A

Rates are calculated as the frequency of demographic events in a population during a specific time period divided by the population “at risk” of the event occurring during that time period

5
Q

Give the equation used to calculate rates

A

Rate = (Numerator / Denominator) x Multiplier

6
Q

What are vital statistics?

A

Largely descriptive statistics which characterise the health of a population

7
Q

What is the numerator used during the calculation of rates?

A

Number of events

8
Q

What is the denominator used during the calculation of rates?

A

Number of people at risk

9
Q

What is the multiplier used during the calculation of rates?

A

A convenient large number used to avoid decimal places resulting in the rate being expressed as “per x population”

10
Q

What is birth rate?

A

Crude rate which indicates the number of live births per 1,000 population per year

11
Q

What is the denominator for birth rate?

A

Total mid-year population

12
Q

What is fertility rate?

A

Number of live births per 1,000 women aged 15 to 49 in a given year

13
Q

Why is fertility rate more refined than birth rate?

A

It relates birth to the age-sex group at risk of having birth

14
Q

What is death rate?

A

Crude rate is the number of deaths per 1,000 population in that population in a given year

15
Q

Describe the calculation used to calculate death rate

A

(Number of deaths / Total population) x 1000

16
Q

What is a better comparison data than death rate?

A

Comparison of age-adjusted death rates between populations

17
Q

What is infant mortality rate?

A

Number of deaths of infants under age 1 per 1,000 live births in a given year

18
Q

Name 3 rates (other than birth and death rates) which are often used in epidemiology

A
  1. Incidence rate (new cases within defined period of time)
  2. Point prevalence rate (Number of cases existing at defined point in time)
  3. Period prevalence rate (Number of cases at any time during defined period)
19
Q

What is demography?

A

Study of changes in population structure

20
Q

What is population projections?

A

Predictions of the future population structure based on assumptions about birth, death and migration patterns

21
Q

How can the age / sex structure of a population be presented?

A

Population pyramid

22
Q

What does a population pyramid show?

A

Composition of a population by age and sex, where the horizontal bars present numbers of males and females in each group

23
Q

Why is there a narrowing peak at the top of the population pyramid?

A

Attrition process accelerates during the older ages

24
Q

Describe a stage 1 population pyramid

A
  • High birth and death rate
  • Each age group shrinks rapidly in size
  • Short life expectancy
  • Population not growing
25
Q

Describe a stage 2 population pyramid

A
  • High birth rate
  • Rapid fall in death rate
  • Increasing life expectancy
  • Population is rapidly growing
26
Q

Describe a stage 3 population pyramid

A
  • Declining birth rate
  • Low death rate
  • More people living to old age
  • Rapidly growing population
27
Q

Describe a stage 4 population pyramid

A
  • Low birth and death rate
  • Longer life expectancy
  • Older population that grows slowly
28
Q

Describe a stage 5 population pyramid

A
  • Low birth rate falls below low death rate

- Older population which begins to shrink in size

29
Q

Why is age standardisation important?

A

Age structure of the populations could affect comparison between two populations

30
Q

Name 2 common methods for performing age standardisation

A
  1. Direct

2. Indirect

31
Q

Name 2 components on both direct and indirect age standardisation

A
  1. Age specific rates

2. Standard population

32
Q

Describe the differences between direct and indirect methods of age standardisation

A
  • Direct gives rate; Indirect gives ratio
  • Direct is “in standard population”; Indirect is “in the groups of be compared”
  • Direct requires only numbers at risk by age group; Indirect requires age-specific rates
  • Direct preferred between country comparisons; Indirect preferred for comparison of small groups
33
Q

What is life expectancy?

A

An estimate of the average number of additional years a person could expect to live if the age specific death rates for a given year stayed the same for the rest of their life

34
Q

What is life expectancy based on?

A

Current death rates

35
Q

Name 3 factors which may affect life expectancy

A
  1. Sex
  2. Present age
  3. Race
36
Q

What is the most commonly cited life expectancy measure?

A

Life expectancy at birth

37
Q

What does a life table provide?

A

Convenient way of summarising death rates in a population at any particular time

38
Q

How many columns are found in a life table?

A

4

39
Q

What is the first column found in a life table?

A

Probability that a person aged x exactly will die before reaching age (x+1)

40
Q

What is the second column found in a life table?

A

Number of survivors to exactly age x of 100,000 live births

41
Q

What is the third column found in a life table?

A

Number dying between exactly age x and age (x+1)

42
Q

What is the fourth column found in a life table?

A

Average period expectation of life at exactly age x, that is the average number of years those aged x will live thereafter based on mortality rates

43
Q

Give an example of another use of a life table not relevant to population

A

Summarise survival of a cohort of individuals who have been diagnosed with a disease e.g. oral cancer