D Kuh

Loss and representativeness in a 43 year follow up of a national birth cohort.

STUDY OBJECTIVE--The aim was to describe rates of loss and assessment of representativeness during 43 years of a national birth cohort study. DESIGN--The study population is a class stratified random sample of all single, legitimate births that occurred during one single week in 1946; it has been studied at regular intervals, so far to 1989. MAIN RESULTS--Losses through death and emigration were comparable to those in the national population of the same age. Response rates from the population resident in Britain have remained high, and the responding population is in most respects representative of the native population born in the early postwar years. Response rates within some serious physical illnesses did not differ from those of the healthy population. CONCLUSIONS--The continuing high response rate and representativeness of this national birth cohort is likely to be the result of home based data collections and of the regular contact to provide feedback of information and to check addresses of the study population.

Burden of disability in a post war birth cohort in the UK.

STUDY OBJECTIVE--To report the prevalence of physical disability in a national sample of 43 year old men and women, and examine the relationship between disability and the consumption of hospital care. To assess the contribution of childhood health and social circumstances to the risk of adult disability, and the socioeconomic consequences of disability. DESIGN--The assessment of disabilities of physical movement was based on criteria developed by OPCS for their national survey of disability. The analysis used data on socioeconomic circumstances from childhood to 43 years and on serious illness in the first 25 years of life collected prospectively on members of the MRC National Survey of Health and Development, the 1946 birth cohort study. SETTING--England, Wales, and Scotland. PARTICIPANTS--A general population sample of 3235 men and women aged 43 years. MAIN RESULTS--Seven per cent of cohort survivors at 43 years were physically disabled and a further 3% reported difficulties although they were not assessed as disabled according to OPCS criteria. The prevalence of severe disability at this age was similar to that derived from the OPCS survey but the prevalence of mild disability was substantially greater. Disability was associated with a greater use of hospital care in recent years and throughout life. Those who had experienced a serious illness in earlier life were over twice as likely to be disabled; certain conditions, such as polio, were associated with a particularly high relative risk. Those who had had a socially disadvantaged start to life were more likely to be physically disabled at 43 years but the strength of this relationship was considerably weakened by adjustment for later social factors, suggesting that social disadvantage throughout life, or during adult life, increased the risk of disability. Taking these results into account the relative impact of disability on income and employment was found to be greatest for those from the unskilled and semi-skilled classes. CONCLUSIONS--The prevalence of physical disability among those in early middle age may be greater than previously estimated. The strong links between childhood ill health and adult disability and its association with high levels of hospital care support longstanding recommendations for better coordination between child and adult health services. Social disadvantages affects the risk of disability and its financial and employment consequences.