Prevalence and incidence of chronic kidney disease stage 3-5 - results from KidDiCo.

BACKGROUND: Chronic kidney disease (CKD) is a global challenge. CKD prevalence estimation is central to management strategies and prevention. It is necessary to predict end stage kidney disease (ESKD) and, subsequently, the burden for healthcare systems. In this study we characterize CKD stage 3-5 prevalence and incidence in a cohort covering the majority of the Region of Southern Denmark and investigate individuals' demographic, socioeconomic, and comorbidity status.

METHODS: We used data from the Kidney Disease Cohort (KidDiCo) combining laboratory data from Southern Denmark with Danish national databases. Chronic kidney disease was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.

RESULTS: The prevalence varied between 4.83 and 4.98% and incidence rate of CKD was 0.49%/year. The median age was 76.4 years. The proportion of individuals with CKD stage 3-5 in the entire population increased consistently with age. The percentage of women in the CKD 3-5 group was higher than in the background population. Diabetes mellitus, hypertension and cardiovascular disease were more prominent in patients with CKD. CKD stage 5 and ESKD were more frequent as incident CKD stages in the 18-49 year olds when compared to older individuals. CKD patients tended to have a lower socioeconomic status.

CONCLUSION: Chronic kidney disease stage 3-5 is common, especially in the elderly. Patients with CKD stage 3-5 are predominantly female. The KidDiCo data suggests an association between lower socioeconomic status and prevalence of CKD.