The Dialysis Outcomes and Practice Patterns Study (DOPPS) in Turkey

Introduction Turkey has one of the largest treated end-stage renal disease (ESRD) patient populations in Europe (N = 66,711). In 2013, the international Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective study of hemodialysis (HD) practices and outcomes, initiated data collection in Turkey. Here we provide comparisons of HD patients in DOPPS-Turkey with other international regions and with patients in the Registry of Turkish Nephrology, Dialysis and Transplantation. Methods DOPPS-Turkey study sites were randomly selected from all Turkish HD units treating ≥25 in-center chronic HD patients. Detailed patient- and facility-level data were collected for 20–30 randomly selected prevalent HD patients per facility. Findings Demographic and comorbidity profiles for DOPPS-Turkey patients were similar to HD patients overall in the 2013 Turkish Registry Report. In Turkey: diabetes was the most common ESRD cause (37%); arteriovenous fistula use was 83%; mean single pool Kt/V was 1.61. Compared with other international regions, Turkey had the highest mean hemoglobin (11.5 g/dL), ferritin (771 ng/mL), and interdialytic weight gain (3.28%), while Turkey had the lowest mean systolic blood pressure (127 mmHg) and erythropoiesis stimulating agent prescription (57%). Turkish patients also reported the highest depression scores. Discussion In this first DOPPS-Turkey report, the DOPPS sample agrees well with national Turkish Registry data. Treatment and laboratory data, and patient-reported outcomes, demonstrate similarities and previously unrecognized contrasts to DOPPS findings in Europe, Japan, and North America. Long-term follow-up of these patients will describe how these differences relate to clinical outcomes within Turkey.