The popularity of life course epidemiology continues apace given its endorsement by the World Health Organization as an approach to understanding the origins of health, well-being and (mainly non-communicable) diseases.
It has an intuitive appeal with its focus on development over time and generations unfolding under different socio-economic conditions.
Led by the UK, there are now many surveys that have followed up large numbers of individuals from birth, re-interviewing their families and themselves at intervals throughout their lives. These longitudinal “cohort studies” have given us much of the data needed to research the life course and have been used extensively by social scientists. They underpin the conclusions by economists that investments at the beginning of life will have greatest dividends in the long-term. Yet if lifecourse epidemiology has taught us anything, it has shown that individual lives are diverse and complex and that there is no “quick fix”.
Time and again, it has been shown that the more social, physical, economic and psychological disadvantage a child is exposed to, the more they are behind at kindergarten and school – a two year difference in verbal ability measured at three, five and seven years for a child with none versus 7+ disadvantages, for example. This suggests that intervening in the pre-school years will permanently reduce the gap, but test the same children again at age eleven and the difference has grown to five years. This is not because the advantaged have surged ahead but because the disadvantaged have fallen further behind. It is a stark reminder that we must not forget our vulnerable children who need targeting for continued support throughout childhood and not just in the early years. Maximising children’s cognitive capabilities is so important because it sets them off on more optimal life course trajectories in work and family spheres. In adult life, as in childhood, each adverse experience such as unemployment, family break-up and poverty increases the risk of poor health.
One of the more consistent findings from lifecourse epidemiology is that social support and networks protect us from poor health, especially as we get older. Lifecourse research emphasises that it is not only public health policy that can improve public health. The older person’s free bus pass in England was introduced in response to a need to reduce social exclusion and in so doing has improved the health of our aging population, partly through increased incidental physical activity.
Now a new generation of life course epidemiological research is evolving with the addition of bio-medical surveys into our cohort studies. Investigating how the social “gets under the skin” to affect our bodies and hence our health status many years later will add to the evidence base for policy. ⁄