Abstract

There is an increasing recognition of epidemic clustering of primarily tubular-interstitial kidney diseases in agricultural communities living in tropical regions across the globe. Although it is currently unclear whether there is a unified underlying aetiology, these conditions have been collectively termed chronic kidney disease of unknown cause (CKDu). CKDu is estimated to have led to the premature deaths of tens to hundreds of thousands of young men and women over the last decade. The impact on the working-age population has also had a profound effect on economic and social development in the affected areas. Thus, there is an urgent need to understand the aetiology and pathophysiology of these condition(s).

International comparisons have provided the first steps in understanding many chronic diseases. However, such comparisons rely on the availability of standardised tools to estimate disease prevalence. This is a particular problem with CKD, since the disease is asymptomatic until the late stages. Furthermore, both the normal distribution of kidney function and the biases inherent in the methods used to estimate the glomerular filtration rate (GFR) in population studies, are highly variable across populations. We therefore propose a simple standardised protocol to estimate the mean and distribution of GFR in populations – the Agricultural eGRE epidemiology (AGREE) study. The methods we present are potentially applicable in any population, but our particular focus is on rural populations in low-and-middle-income countries (LMICs), since these appear to be most susceptible to CKDu.