Background: An ecological study is a useful epidemiologic tool for public health surveillance and establishment of a new hypothesis. Here, we used an ecological study to analyze the association between birth weight and end-stage renal disease (ESRD).
Methods: We performed ecological regression analysis by using data obtained from the national database of Japan. The data include regional incidence of ESRD beginning maintenance dialysis therapy, regional rate of low-birth weight (LBW) newborn babies of all newborn babies, the average birth weight of newborns, the body mass index (BMI) score, the prevalence of diabetes mellitus, and the amount of payment for drugs, in the 47 prefectures of Japan.
Results: The mean regional rates of LBW newborn babies from 1999 to 2008 statistically correlated with the mean incidences of ESRD during the same time periods in each prefecture. The correlation coefficients between the yearly rate of LBW newborns and the yearly incidence of ESRD in each prefecture became higher after statistically considering the effects of the cost per resident for prescriptions of angiotensin II receptor blocker and angiotensin converting enzyme inhibitor. Furthermore, the final model predicting the regional incidence of ESRD by a stepwise multiple regression analysis consisted of the average BMI score and the rate of LBW newborns in each prefecture.
Conclusion: Although this study cannot explain the reason for this unexpected correlation between the regional rate of LBW babies and the regional incidence of ESRD at the same time points, the statistically significant correlations shown in this study should be taken into consideration.