Chronic kidney disease in Spain: analysis of patient characteristics, incidence and direct medical costs (2011-2017).

Objectives: To review the characteristics of patients with chronic kidney disease (CKD) who attended primary and specialized care centers in Spain, and to analyze patients' use of medical resources and direct medical costs of specialized care.

Methods: Records of patients with CKD admitted to primary and specialized healthcare centers in Spain between 2011 and 2017 from two national discharge databases were analyzed in a retrospective multicenter observational study. Records were classified into one-to-five CKD stages plus a 5b stage, indicating end-stage renal disease.

Results: Most of the patients registered in hospital settings were in stage 5. Registered secondary conditions included hypertensive chronic kidney, diabetes, anemia, hypercholesterolemia, and hypertension. The number of cases registered in primary care settings increased over time, whereas in specialized care centers incidence decreased; hospital incidence of CKD in 2017 was 10.72 per 10,000 persons. Mean in-hospital mortality was 5.90%, which remained stable during the study period. Mortality was associated with respiratory and heart failure. Mean length of hospital stay was 8.19 days, decreasing over the study period, whilst increasing with CKD progression. Mean annual direct medical cost of specialized care was €10,436 per patient. Complications of a transplant and bacterial infections were responsible for major increases in medical costs, that otherwise decreased over the study period.

Conclusions: The costs of specialized care decreased with the length of hospital stay reduction. Cardiovascular risk factors were crucial in in-hospital mortality. This study provides population-based data to assist decision-makers at the national level and to contribute to worldwide evaluations and disease surveillance.