Croatian registry for renal replacement therapy for the year 2004

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CROATIAN REGISTRY FOR RENAL REPLACEMENT THERAPY (CRRRT) has been collecting data during the past 5 years. All dialysis and transplant centers participate voluntarily and regularly. In the year 2004, for the first time, electronic forms were used to record individual data, and data were sent to Registry by e-mail. Accuracy and speed of data collection, as well as data processing has increased significantly.
After 5 years, CRRRT is deriving data not only describing the present state, but also showing trends of changes in number of patients on renal replacement therapy, demographic characteristics of treated population, leading causes of renal failure, and, for the first time, survival curves on renal replacement therapy. Importance of survival data is manifold. It enables insight in treatment quality, and comparison with results in other regions. It is the basis for giving prognosis to patients facing with a need for renal replacement therapy.

registar

At the end of the year 2004 in Croatia, renal function has been replaced in 3582 patients. The majority were treated by haemodialysis (74%), 7% were on peritoneal dialysis (CAPD or APD), and the number of transplanted patients has increased to 19%, after significant progress in transplantation attained in 2004. Prevalence has reached 807 pmp (number of treated at 31.12.2004. per million population). Prevalence of renal replacement therapy in Croatia in the year 2003 was 790 pmp, in the range of prevalence in Scandinavian countries, according to the ERA-EDTA Registry Report for 2003. (ERA-EDTA Registry Report for 2004. has not been released yet).

prirast

Population on renal replacement therapy in Croatia has increased by 218 patients during the year 2004, as a result of recruitment of new patients and moving in from abroad on one side, and dying and moving out from Croatia on the other. For the first time withdrawal from dialysis was reported, as it is to be expected with high incidence. Broad accessibility to renal replacement therapy results in unsuccessful treatment of some patients, and leads to occasional stopping of futile therapy.

During the year 2004, 688 new patients started renal replacement therapy (686 with dialysis, and 2 with preemptive kidney transplantation). As expected, male gender prevailed; men to women ratio were 56% vs. 44%.
Incidence rate of renal replacement therapy (new patients during the year per million population) in 2004 was 155 pmp. Incidence rate in Croatia is comparable to incidences in economically well-developed countries of northern and western Europe. According to the ERA-EDTA Registry report for 2003, incidence rate in Croatia (131 pmp) was close to incidences in Sweden, Finland, Norway, Netherlands, Austria and Denmark.

Not only incidence, but increase in incidence is constantly growing.

Patients starting dialysis are older every year. Median age of incident patients in 2004 was 65 years (63 years for men and 67 years for women). Three patients started dialysis treatment in their tenth decade (age 90 to 93 years).

Looking back at previous reports, permanent growth in older age groups is evident, while there are no significant changes in younger age groups. The highest growth in absolute numbers of patients is evident in the age group 70-79 years.

Diabetes is the most frequent cause of renal failure in patients starting renal replacement therapy. Diabetic nephropathy is reported as primary renal disease in 29% of new patients. If patients missing the diagnosis of primary renal disease are excluded, percent of diabetic nephropathy reaches 31%. In addition, diabetes accompanies other known primary renal disease in 0,5% of patients. Altogether, diabetes was present in 31,5 % of patients starting renal replacement therapy in 2004.

Diabetic nephropathy is constantly the most frequent cause of renal failure in new patients, from the first CRRRT report in 2000. Vascular kidney diseases (hypertensive nephropathy, ischemic nephropathy, atheroembolic disease, vasculitides) are still occupying the second place, reached in 2003., and have further increased advantage over glomerulonephritis. According to frequency, glomerulonephritis is the third cause of renal failure in Croatia.

At the end of the year 2004, 258 patients were treated with peritoneal dialysis. For 41 newcomers, it was the first treatment, and for 36 patients CAPD followed haemodialysis or kidney graft failure. During the 2004 year, the number of peritoneal dialysis patients grew by 12%.

Kidney transplantation was very successful in the year 2004 in Croatia. For the first time, more than 100 kidney transplantations were done in a year (115 kidney transplantations in Croatia, 2 transplantations for Croatian patients in Austria). Ten combined kidney-pancreas transplantations for diabetes type 1 patients were performed. Fruitful year for transplantation (26 kidney transplants pmp) resulted in increased percent of patients with functioning kidney graft (19%) in the population on renal replacement therapy.

After 5 years of registry follow up, survival curves for patients on renal replacement therapy have been constructed. Now we have the precise data to answer the frequent questions: „How long do the patients on dialysis live?“ and „What can I expect when I start dialysis? Five-year survival, from the first day of renal replacement therapy, for patients that had started treatment in 2000 is 52%. Survival curves make the basis for founded prognosis of survival for future patients.
There is no difference in survival between males and females.

Survival on renal replacement therapy is dependant not only on quality of treatment of renal failure, but even more on accompanying diseases. Diabetes decreases chances of 5-year survival by more than 20%.
Survival curves enable comparing treatment results in Croatia with results in other states and regions. The care should be taken that data are presented in the same way. To compare Croatian data with ERA-EDTA registry survival data, only patients treated with dialysis, and alive at the 90. day of therapy are depicted in the slide 13. Five year survival for diabetics was 36%, and for nondiabetics 58%. Data are comparable with survival curves depicted in ERA-EDTA registry report for 2003, where 5-year survival in diabetics is 30%, and in nondiabetics 48%. Treatment quality in Croatia, according to survival data is quite satisfactory.

As expected, age is important determinant of survival on renal replacement therapy. For patients aged 50 or less, 5-year survival was 84%. In the age group 51-65, 5-year survival was 65%, and in patients over 65 years, 5-year survival was 32%. It has to be remembered, that half of patients that started renal replacement therapy in 2004 were 65 or older.

For patients over 65 on renal replacement therapy, survival curves for diabetics and nondiabetics differ only by 10% during the second, the third and the forth year of treatment, and merge in the fifth year of dialysis. The difference in survival between diabetics and nondiabetics over 65 years of age is not statistically significant.