The methodology is described in detail for the population-based Isle of Youth Study (ISYS) for epidemiological evaluation of CKD associated with cardio-cerebral vascular disease, arterial hypertension, diabetes mellitus, and other risk factors.
Background: Chronic kidney disease emerges as an important and growing global health problem associated with an increase in the incidence and prevalence of the above mentioned diseases. ISYS Objectives: Ascertain CKD morbidity and its relation to chronic vascular diseases and other risk factors in whole population of Cuba's Isle of Youth special municipality.
Method: 96.6% of the Isle of Youth's total population (80,117 inhabitants) was studied, all ages and both sexes, November 15, 2004-April 30, 2006. The public was offered general information on the objectives and benefits of the study, and participants provided informed consent. Active screening was performed via personal interview questionnaire and urine sample to determine markers of kidney damage: proteinuria and hematuria (Combur-10-Test) and microalbuminuria (Micral-Test), according to a diagnostic algorithm. For those testing positive for any marker, serum creatinine was studied and glomerular filtration rate (GFR) calculated - in adults by Cockcroft-Gault and Modification of Diet in Renal Disease (MDRD) formulas and in children aged <15 years, by Schwartz - to stratify CKD by stages. Blood pressure, height, weight, and body mass index (BMI) were determined.
Expected results: Prevalence of kidney damage markers in general population and risk groups; relationship in population between CKD and cardio-cerebral vascular disease, diabetes mellitus, hypertension, and other risk factors; comparison of Cockcroft-Gault and Modification of Diet in Renal Disease (MDRD) formulas for measuring the GFR and their application to studies involving mass population screenings; and stratification of CKD in population.
Conclusions: ISYS Phase I, active screening of markers for renal damage was concluded using the methodology described above; results are pending publication. (Abstract) Erratum Almaguer López M, Herrera Valdés R, Chipi Cabrera J, Toirac Cabrera X, Castellanos Rabanal O, Bacallao Gallestey J. Design & methodology of the Isle of Youth community-based epidemiological study of CKD, cardio-cerebral vascular disease, hypertension, and diabetes mellitus (ISYS). MEDICC Review. 2007;9(1):23-9. The correct formula for MDRD appearing on page 27 is: MDRD GFR = 186.3 x serum creatinine (mg/dL)-1.154 x age-0.203 x 0.742 for females x 1.21 if the person is black.