The importance of life course research in an aging population

• ESRC International Centre for Life Course Studies in Society and Health

• UC London, Imperial, Essex, Manchester

Increasing life expectancy

62

64

66

68

70

72

74

76

78

80

82years

Men Women

1976

1986

1996

2000

2005

Falling mortality in ‘third age’

0

10

20

30

40

50

60rate/1000

Men 65-74 Women 65-74

1976

1986

1996

2002

2006

Heart disease mortality

0

500

1000

1500

2000

2500

3000

3500

4000

Men Women

Rates per million population:E&W

19711981199120012006

Lung cancer mortality

0

200

400

600

800

1000

1200

Men Women

Rates per million population: E&W

19711981199120012006

Reproductive cancer mortality

0

200

400

600

800

1000

1200

Men: prostate Women: breast

Rates per million population: E&W

19711981199120012006

Healthy life expectancy

SOURCE: ONS and Govt Actuaries Dept http://www.statistics.gov.uk/cci/nugget.asp?id=934 on 1 May 2008

60

65

70

75

80

85

90

95

100

1975 1985 1993

Year

% e

mp

loye

d Prof/Manag

Intermed

Skilled

Semi-skilled

Trends in employment by socio-economic group: Great Britain, men, 1975-93

Trend in economic inactivity 1973-1993: Intermediate occupations

Healthy

Ill

40%

0

1973 1993

% inactive

Trend in economic inactivity 1973-93: semi and non-skilled manual

40%

0

Ill

Healthy

1973 1993

% inactive

Risk of limiting long term illnesss in 1991 and unemployment 1971, 1981

1

1.94 2.03

0

0.5

1

1.5

2

2.5

Never unemployed Unemployed 1981 Unemployed 1971

Odds of LLTIOdds of LLTI

Economic status 1971, 1981 and 1991

0

510

1520

25

3035

4045

50

Employed Unemployed ALL

Economic status 1971

% n

ot

emp

loye

d 1

991

Employed1981

Unemployed1981

Most unemployed men 1971-1981 regain work by 1991

0

10

20

30

40

50

60

70

80

90

Employed 1981 Unemployed 1981

Employed 1971Unemployed 1971

Employment history 1971-1991 and social class 1991: % in non-manual class 1991

0

5

10

15

20

25

30

35

40

45

50

%

Emp 71 & 81 Emp 71 Unemp81

Unemp 71 Emp81

Unemp 71 & 81

Emp 1991Unemp 1991

Risk of limiting long term illness by unemployment in 1971, allowing for

subsequent labour market disadvantage

0

0.5

1

1.5

2

2.5

Unadusted Class+unemp1981

& class 1971

Employed 1971

Unemployed 1971

Usefulness of a Birth Cohort Study

• These kind of data allow us to look in far more detail at life-courses

• Could it be that people get into a trajectory that increases the risk of unemployment, poor health, and early exit from the labour force?

• If so, how early does this start?

Relationship of unemployment to father’s social class at birth

0

1

2

3

4

5

6

Unadjusted Adjusted

I-IIIIINIIIMIVV

Odds ratioOdds ratio

Adj. crowding, education, region,height at 7, BSAG, parents’ heights

Adj. crowding, education, region,height at 7, BSAG, parents’ heights

Unemployment 12+ months by household overcrowding in childhood

0

0.5

1

1.5

2

2.5

Unadjusted Adjusted

> 1 PPR1-1.5 PPR1.5 + PPR

Adj. Father’s class, education, region, heights, BSAG

Adj. Father’s class, education, region, heights, BSAG

Odds ratioOdds ratio

Persons per room

Persons per room

Unemployment 12+ months by social adjustment (BSAG) at 11 years

0

0.5

1

1.5

2

2.5

3

3.5

Unadjusted Adjusted

Least2nd3rd4thMost

Degree of maladjustment

Degree of maladjustment

Odds ratioOdds ratio

Unemployment 12+ months by education

0

0.5

1

1.5

2

2.5

3

3.5

Unadjusted Adjusted

No qualsSub OO levelA levelFurtherDegree

Adj. Fathers class, crowding, region, BSAG, height

Adj. Fathers class, crowding, region, BSAG, height

Odds ratio

Odds ratio

Precursors of unemployment

• Material circumstances in the family of origin, as indicated by father’s class at birth and overcrowding

• Behavioural adjustment of the child

• Educational attainment

Importance of precursor factors for risk of 12+ months unemployment (mutually

adjusted)

0

0.5

1

1.5

2

2.5

3

Class at birth Crowding Education Region Height 7 yrs

BestWorst

Environmental determinants of unemployment: regional

unemployment rates

• We have looked at the importance of background factors of individuals

• Important not to forget the environment, i.e. in this case, the local demand for labour.

• Regional unemployment rates had a strong effect on the risk of unemployment regardless of all other factors.

Unemployment 12+ months by standard region

0

0.5

1

1.5

2

2.5

3

3.5

Unadjusted Adjusted

N-WScotlandNorthernWalesMidlandsE&W RidingN MidsS-WLondon & SEEasternSouthern

“Life-course” determinants of unemployment risk

• Cohort studies enable us to begin to see sequences of events an unfolding processes.

• Any measure may be acting as an indicator rather than a “cause”.

• Interdependence of effects and time order are difficult to do analytical justice to.

Risk of 1 year+ unemployment 1981-1991 by height at age 7

0

1

2

3

4

5

tallest 2nd 3rd 4th Shortest

Unadjusted

Adjusted

Adjusted for birth class, overcrowding, education, region, height, BSAG score and parents height

Adjusted for birth class, overcrowding, education, region, height, BSAG score and parents height

Family conflict by height at age 7 (1/5ths)

0

5

10

15

20

25

30

35

Height at age 7

% w

ith

fam

ily

conf

lict

Shortest234Tallest

Risk of being in shortest 1/5 height at age 7 by paternal social class

0

1

2

3

4

5

6

Class I II IIINM IIIM IV V

Unadjusted

Adjusted

Adjusted for family conflict and crowding

Adjusted for family conflict and crowding

Very long term influences and markers

• Large effect of paternal social class appears to be to an important extent the result of increased family conflict as well as material circumstances in the home

• The strange-looking relationship of height at age 7 to later unemployment is likely to be due to the sensitivity of child height as an indicator of both material and psycho-social conditions in early life

Independent role of unemployment in the life course process

• Caution against seeing everything as pre-determined in early life

• Take groups of study participants classified according to earlier influences

• Examine ‘effect’ of unemployment 1974 (age 16) to 1985 (age 27) on social circumstances at age 33 (1991)

• Include only those in stable employment since 1985, so we are only looking at longer term processes.

Variable definition

• Goldthorpe service class;

• Top 3/5 income distribution;

• Owning or purchasing home at age 33.

• “Socio-economic advantage score”

• Scored 0 (low) to 3 (high).

• Unemployment: none, 1-12 months, 13+ months between ages 16 and 27

Effect of unemployment duration on relationship between father’s class and

adult socio-economic circumstances% of men with most favorable socio-economic circumstances at age 33

0

10

20

30

40

50

60

None 1 to 12 13+

months of unemployment 1981-5

Non-manual

Manual

Odds of least favourable socio-economic circumstances at age 33 by father’s class at birth and months of

unemployment

0

2

4

6

8

I/II IIIN IIIM IV V

father's social class

od

ds

ratio Unadjusted

Adj unemp

Odds of least favourable socio-economic circumstances at age 33 by non-verbal ability at age 11 and unemployment

0

0.2

0.4

0.6

0.8

1

1.2

Lowest 2nd 1/5 3rd 1/5 4th 1/5 Highest

Non verbal ability at 11

Odd

s ra

tio Unadj

Adj unemp

Changing trajectories

• These studies used the 1958 British Birth Cohort (NCDS)

• What would the patterns look like in the 1970 Cohort?

• What would they look like in the 1946 Cohort?

The ‘long shadow’

• It is increasingly found that declines in functioning with age are related to early life conditions and processes

• Much economic inactivity precedes retirement age, and this will only get worse if retirement age is delayed

• Are the processes that increase the risk of work disability the same as those what decrease healthy life expectancy?