Vital Statistics: Census & Fertility

Professor Michael ClarkeDept of Epidemiology & Public

Health

Uses of EpidemiologyJ.N. Morris

1. Size of Problem

2. Historical Perspective

3. Aetiological Factors

4. Planning and Evaluating Services

ObjectivesFollowing the session, you should be able

to:• Outline and distinguish between the

processes of birth registration and notification

• Discuss the main determinants of fertility in the UK over the last 30 years

• Define and illustrate the use of:a. The crude birth rateb. The general fertility ratec. Age-specific fertility rates

Objectives

• Outline the changes in fertility and mortality that have occurred in England during the last one hundred years

• Describe the uses and limitations of population estimates and projections

Objectives• Describe the characteristics of the

national census and outline the history of census taking in England

• List the major items of information collected in the English 1991 census and the relevance of these data to health and social services

• Illustrate how demographic characteristics of populations determine health and social service priorities

Birth Statistics

Registration

Notification

Birth Statistics

1. Registration of Births (1837) Birth to be registered within six weeks

with the Registrar of Births, Marriages and Deaths, by an informant (usually the parent).

Birth Statistics

2. Notifications of Births (1907) Within 36 hours by the attendant at the

delivery, to the District Medical Officer – so community services (health visitors) can be mobilised.

Birth Rate

• Live Births / 1000 population

Age -14 15-44 45+

Males

Females

Fertility Rate

• Live Births / 1000 female population aged 15 -

44 Age -14 15-44 45+

Males

Females

Total Period Fertility Rate

“ The average number of children that would be born to a hypothetical woman if she experienced the age specific fertility rates of a given year (or period) throughout her child bearing life.”

Ugh!!

E.g. England & Wales - 1992

aged 16 ……. have 3,800 .0126 aged 17 ……. have 8,882 .0294

aged 28 .1205

aged 44Total Period Fertility Rate 1.7

N.B. There were 222 live births to women aged less than 15 yrs in 1992 in Wales

Women aged 15 (301,600) have 1,090 births .0036

Fertility & Abortions in England and Wales & Selected Health Authorities - 1985

TPFR TPAR TPCREngland & Wales 1.8 0.4 2.2Leicestershire HA 1.8 0.3 2.1Bradford HA 2.2 0.3 2.4Islington HA 1.7 0.8 2.5Tower Hamlets HA 2.6 0.8 3.5TPFR = Total Period Fertility Rate

TPAR = Total Period Abortion Rate

TPCR = Total Period Conception Rate

Determinants of Fertility

1. Fecundity – physiological ability to reproduce. (fertility - realisation of the potential) Increase in sterilisation & Hysterectomies

2. Sexual activity Economic climate

Determinants of Fertility3. Contraception (Bone, 1978) Fecund, not preparing nor trying to conceive.

- pill - I.U.D. - C.I. - Condom - Cap - Other - None

42% 9% 7% 25% 3% 6% 11%

Contraception – Current use for women aged 16-49 in Great Britain, 1993

0 5 10 15 20 25 30

PillCondom

IUDWithdrawal

Other non-surgical*Male sterilisation

Female sterilisationNo sexual relationship

PregnantOther non-users

Percentage

* Includes the cap, safe period, spermicides and injection

Trends in contraceptive use 1970-1983

0

5

10

15

20

25

30

35

Perc

enta

ge

Sterilisation

IUD/ Cap

Withdrawal

Pill

Condom

1970

Family planning: changes and effects (England & Wales), M Bone

1976

Family formation survey 1976 (GB), K Dunnell

1983

General Household Survey 1983 (GB)

Determinants of Fertility

4. Abortion - 179,590 England and Wales 1997

Population Estimates & Projections

• Estimates Apply what is known from deaths, births, migration – to the present.

• Projections Future orientated given certain assumptions.

Population Estimates – E.g. Leicestershire

1981 858.8 Census Base1989 Migration

+ 9.4 excess inflow over outflow +23.8 excess births over deaths892.0

Actual & Projected Live Births, 1966-94 England and Wales

450

550

650

750

850

950

1966 1977 1986

Low variant

Principal

High variant

Actual

Actual & Projected Live Births, 1966-94 England and Wales

450

550

650

750

850

950

1966 1977 1986

Actual

High variant

Principal

Low variant

The Decennial Census

• A census is (United Nations definition) ‘the simultaneous recording of demographic

data by the government at a particular time, pertaining to all persons who live in a particular territory’

Therefore a census is:

• Run by government • Covers a defined area• Personal enumeration (or a person in each

household)• Simultaneous • Universal • Regular intervals (10 yrs England & Wales)

The census describes

• Households and

• People

See 1991 specimen form in Handbook

Census data provides information of value to health workers:1. Population structure, young, old, very old,

ethnic minorities, household amenities – which in turn determine the structure of services.

2. Base populations for the calculation of fertility and mortality rates.

3. Deprivation measures e.g. DoE Index unemployment, overcrowding, lone pensioners, single parents, born in the new commonwealth, lacking basic amenities

Europe: population by age and sex, 1950 - 2040

030 20 10 0Population (000s)

>8075-7970-7465-6960-6455-5950-5445-4940-4435-3930-3425-2920-2415-1910-14

5-90-4

10 20 30

1950Male Female

Europe: population by age and sex, 1950 - 2040

030 20 10 0Population (000s)

>8075-7970-7465-6960-6455-5950-5445-4940-4435-3930-3425-2920-2415-1910-14

5-90-4

10 20 30

2000Male Female

Europe: population by age and sex, 1950 - 2040

030 20 10 0Population (000s)

>8075-7970-7465-6960-6455-5950-5445-4940-4435-3930-3425-2920-2415-1910-14

5-90-4

10 20 30

2040Male Female

70-74

65-69

60-64

55-59

50-54

45-49

40-44

35-39

30-34

25-29

Population of Asians and Non-Asians in Leicester in 1988

0Percentage

5101520 0 5 10 15 20

FemalesMales

AsiansNon Asians

70-74

65-69

60-64

55-59

50-54

45-49

40-44

35-39

30-34

25-29

Projected sub-populations in Leicester in 2008

0Percentage

5101520 0 5 10 15 20

FemalesMales

AsiansNon Asians