Saturday, February 19, 2011

Effects of Childhood Chronic Conditions

Childhood chronic illnesses such as asthma became increasingly prevalent in the late 20th century and first decade of the current century, as did childhood obesity and childhood mental health problems. A complex question arises as to how to predict the effect of increasing childhood problems on later adult health. It is, of course, possible that a lot of kids will simply 'grow out' of the condition that they face, particularly for less debilitating forms of their condition. However, it is also possible that the rise in conditions such as asthma, type II diabetes etc., represents a very ominous development for the future of adult health in industrialised countries. Estimating dynamic health effects is really tricky for the reason familiar to most readers of this blog, namely that there are many confounding factors that influence both child health and adult health e.g. poor children may experience a whole range of disadvantages that, if unmeasured, might make a correlation between child and adult health look bigger than the actual causal effect. One attempt to get around this is the use of family fixed effects and within sibling designs. Some of the recent papers of Jason Fletcher in Yale are really worth reading for the use of these designs. His recent paper in the Journal of Health Economics on asthma provides some of the first credible estimates of the effects of childhood asthma on adult health. This is an undeveloped but really important literature and one that is growing in importance.

In the case of Ireland, it is really difficult to project the effects of child chronic illness forward. Some of us here have been working on ways of estimating the effects of the decline in acute shocks during the 1940s and there are a number of potential strategies on this side. However, we do not have any real nationally representative data on childhood chronic conditions that have followed children through time into adulthood. The recent child health study led by TCD offers the possibility of doing this type of work in the future. The chronic illness rates are in the document. My first impression is that they look low (10 per cent in total, with about half being respiratory with the vast majority - 92 per cent or so of the ten per cent - being described by the parents as being not debilitating). To quote the report: "These figures mean that just under 1% (0.7%) of all 9-year-olds had a chronic illness or disability that resulted in their being ‘severely hampered’ by it in their daily activities." This might be a very good sign but consistency of measurement across countries is an issue that plagues childhood chronic illness research. In general, this will be an interesting and vital area of research over the next 50 years.

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