Communicating public health risk to the general public and decision makers can be a challenging task. Many of the epidemiological measures used to report risk such as RR and OR may indicate how strongly exposure and disease are associated, but they do not indicate directly the benefits that could be gained by the population if the exposure is modified or eliminated.14
, a recently described measure, allows the population burden of a risk factor to be quantified and expressed in a way that both healthcare professionals and the general public will find easier to conceptualise.
In this paper, we have calculated PIN‐ER‐t for three chronic childhood conditions in order to estimate the population burden of low rates of breast feeding on babies born in the UK in 2002. We have estimated the number of cases of coeliac disease, asthma and obesity that could be prevented in this population over 7, 8 and 9 years, respectively, if all the babies had been breast fed. We have also estimated the number of cases that could be prevented at different prevalence levels of breast feeding. The results of this study show that the impact of low rates of breast feeding on the UK population with regard to these chronic disorders is significant. Increasing the prevalence of breast feeding could help reduce the incidence of these disorders.
The use of the PIN‐ER‐t statistic allows the population impact of “lack of breast feeding” to be expressed in simple numbers which could be helpful in risk communication, and would be useful in public health campaigns aimed at promoting breast feeding. PIN‐ER‐t can be applied to other conditions which are known to be associated with lack of breast feeding in different populations in the world in order to quantify the local burden of low rates of breast feeding.
In this paper, we have assumed that the reported OR for the association between “no breast feeding” and asthma, coeliac disease and obesity approximated to RR. When the prevalence of the outcome of interest is small, the OR will approximate to the RR, but it must be noted that ORs generally tend to overestimate the size of the effect compared with RRs.5,15
It must also be noted that the estimated population impact numbers above (33
100 for asthma, 2655 for coeliac disease and 13
639 for obesity) are only achievable if “no breast feeding” as a risk factor at the specified times was completely eliminated in babies in England and Wales born in 2002, that is if all the babies were breast fed. However, such an aspiration will not be realistic as the chance of getting all mothers to breast feed their babies for months is very low indeed. It is however possible to estimate cases of the disorders that could be prevented if the current prevalence of breast feeding was increased to higher prevalence levels. Tables 1–3, respectively, show the number of cases of asthma, coeliac disease and obesity that could be prevented at different prevalence levels of breast feeding. For example, for asthma, the number of cases that could be prevented in this population over 9 years are 3759, 9475, 12
104 and 16
753 at breast feeding prevalence rates of 40%, 54%, 60% and 70%, respectively.