At the end of 2005 in Croatia, renal function was substituted in 3708 patients. Haemodialysis was used in 73%, peritoneal dialysis (CAPD or APD) in 7% of patients, and share of transplantation has increased to 20%. Prevalence has attained 836 pmp (number treated per million population). As 2005 report has not been released yet, ERA-EDTA Registry report 2004 is used for comparison. Prevalence of RRT in The Netherlands was 704 pmp, in Denmark 768 pmp, in Sweden 801 pmp, in Austria 858 pmp, and in Slovenia 869 pmp. Prevalence of RRT in Croatia is similar to prevalence in developed countries of Europe.

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During 2005, in 637 patients renal replacement therapy has been started. Incidence of RRT in 2005 (number of new patients in the year per million population) was 144 pmp. Incidence of RRT in Croatia is comparable to incidences in developed countries in north, west and central Europe. According to ERA-EDTA Registry report for 2004, incidence of RRT was in Finland 94 pmp, in The Netherlands 105 pmp, in Sweden 122 pmp, in Slovenia 127 pmp, in Denmark 133 pmp, in Austria 159 pmp, and in Italy 173 pmp.

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For the first time since 2000, incidence in 2005 is not higher than in the previous year. If this trend is to continue, it might be the early sign of stabilization of inflow of new patients, observed already in some regions with developed RRT.

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Median age of patients that had started dialysis in 2005 was 66 years. For the first time, the most numerous group were patients 70-79 years of age, one third of patients had started RRT in their eighth decade. Dialysis was started in one ninety-three year old man.

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Patients starting RRT are older every year. Median age increases by at least 1 year in every consecutive registry report. Age distribution curves constantly expand to the right, while in younger ages there are no changes.
Lower incidence in 2005 is obviously not consequence of restricted access to dialysis, because older persons are the first to be denied dialysis in shortage. New dialysis centers are opened, and old ones are increasing capacities. Slowing of incidence growth might be the result of more serious assessment of patient benefit on dialysis treatment.

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During 6 years of CRRRT follow up, diabetes continues to be a leading cause of renal failure. In 30% of patients starting RRT, diabetic nephropathy is primary kidney disease. Vascular kidney diseases (hypertensive nephropathy, ischemic nephropathy, vasculitis) are positioned on a second place from 2003 on. In almost half of the patients kidney failure is caused by systemic diseases affecting kidney (diabetes, hypertension, atherosclerosis). Glomerulonephritis by 15% is positioned on the third place as a cause of renal failure. Primary kidney diseases (glomerulonephritis, pyelonephritis, interstitial nephritis, polycystic kidney disease, endemic nephropathy) are all together responsible for only one third of terminal renal failure.

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During 2005 year, 469 patients on RRT had died, and crude mortality was 13%. Majority of dead had been treated by haemodialysis, and crude mortality on haemodialysis (16%) was higher than on other treatments. A major difference in patient characteristics in groups treated by haemodialysis, peritoneal dialysis and transplanted patients precludes direct comparison. The longest life on RRT was 34 years (8 years of transplantation and 26 years of haemodialysis).

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Age differences between patients on haemodialysis (HD), peritoneal dialysis (PD) and transplanted (TX) are evident from age distribution curves, and from age medians (HD:PD:TX=63:55:49 years). Diabetes is differentially distributed between treatments (HD:PD:TX=19%:23%:7%), as well as hypertensive nephropathy (HD:PD:TX = 16%:15%:3%).

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Over half of deaths were caused by cardiovascular diseases, irrespective of treatment modality and absolute mortality. In peritoneal dialysis patients, infections are more prominent, and transplanted patients succumb to malignancies more frequently.

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From the start of CRRRT in 2000, peritoneal dialysis constantly grows, measured in number of patients and as share in RRT. At the end of 2005, there were 274 patients on peritoneal dialysis, making 7,2% population on replacement therapy. Six-year follow up enables analysis of treatment results attained by peritoneal dialysis.

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For patients in Croatia, peritoneal dialysis is not a short-term method. After 5 years, 68% of alive patients were still on peritoneal dialysis, and 32% were transferred to haemodialysis. Rate of method failure was not increasing with time.

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Five-year patient survival on peritoneal dialysis was 64%, without signs of increasing mortality after 3 years. Five-year patient survival on peritoneal dialysis is much higher than common survival for incident patients on all forms of RRT in CRRRT Report 2004 (64% vs. 52%).

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To enable proper comparison, only patients treated exclusively by peritoneal dialysis or haemodialysis from the start of RRT were abstracted. In incident peritoneal dialysis group patients are younger, there are less diabetics, and more women). Selection is evident, led more by medical professionalists than by patient preference.

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Peritoneal dialysis and haemodialysis survival curves significantly diverge from the beginning. Peritoneal dialysis survival is 17% higher from 12 months till 60 months, with high statistical significance (Log rank test p<0.0001).
Hazard ratio (HR) for death on haemodialysis is 50% higher than on peritoneal dialysis, after adjustment for age, gender, diabetes and hypertensive nephropathy: HR = 1.5 (95% CI 1.1-2.0).

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Is benefit of peritoneal dialysis equal for all patients? For all ages? Survival on peritoneal dialysis and haemodialysis was compared in 2 age groups. In patients under 60 years, benefit of peritoneal dialysis over haemodialysis was greater and sustained over 5 years. In 60 years and older, survival on peritoneal dialysis is better, but advantage decreases after 3 years. Survival difference is significant in both age groups (p<0.02).

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Is benefit of peritoneal dialysis equal for nondiabetics and diabetics? Separately analysis of nondiabetics and diabetics, discloses greater continuous and statistically significant (p<0.0001) benefit of peritoneal dialysis in nondiabetics. In diabetics survival on peritoneal dialysis is slightly better, but advantage decreases after 3 years. Cumulative difference is approaching the level of statistical significance (p=0.0516).

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Does the age in diabetics interfere with peritoneal dialysis benefit? Benefit of peritoneal dialysis compared to haemodialysis in diabetics under 60, and 60 and over is not statistically significant. Only in older diabetics survival curve of haemodialysis crosses peritoneal dialysis curve, signifying loss of advantage of peritoneal dialysis, but without statistical significance.

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After 6 years of CRRRT some important answers are emerging. Peritoneal dialysis has confirmed survival benefit when used as a first method of RRT. The advantage of PD first is greatest for younger patients and nondiabetics.

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All kidney transplantations in Croatian residents are recorded in CRRRT, irrespective of weather performed in Croatia or abroad. In 2005, 99 patients received kidney transplant. Eighty-nine kidneys were cadaveric, and 10 kidneys were from alive related (9) and unrelated (1) donors. Eleven transplantations were combined: 7 kidney+pancreas, and 2 kidney+liver.

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During 2005, function was lost in 27 transplanted kidneys, 6 transplanted in 2005. There were 21 deaths of persons with transplanted kidneys, 4 of them were transplanted in 2005. At 31 December 2005 there were 738 patients with functioning kidney transplant. Twenty percent of patients on RRT are transplanted.

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Transplantations performed from 2000 to 2005, the time covered by CRRT, are the basis for analysis patient and kidney survival.

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In six years, 489 transplantations were done, 409 cadaveric, and 80 from living donor. Graft function was not achieved or was lost in 20 patients. Eleven patients died with functioning graft.

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Five year survival of patients transplanted 2000-2004 is 96%.

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Five year survival of kidneys transplanted 2000-2004 is 90% (10% of kidneys were lost in 5 years because of graft failure or patient death).

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Data from ERA-EDTA Registry report 2004 on survival of cadaveric kidneys transplanted 1995-1999 are presented.
To make comparison with European results, data on 409 cadaveric transplants in CRRRT were stratified by age. Analyses of kidney survival were performed separately for each age stratum. Survival of transplanted cadaveric kidneys in Croatia is better in all age groups, even after including 5% improvement expected to occur in European 2000-2004 cohort.

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Tedious, several-years long labor of numerous invisible workers in nephrology generate important results every year more.
Slowing of inflow of new patients in 2005. was surprising and promising observation.
High prevalence and incidence of RRT in Croatia are measures of broad accessibility.
Good survival on all modes of RRT is result of high treatment quality. The best survival probability is offered by start of RRT on peritoneal dialysis. Survival of transplanted patients and kidneys is comparable to good European results, and could be an additional impetus for growth of transplantation.

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It is difficult to thank to all individual participants in registry functioning, with risk of omitting someone unintentionally. Therefore, acknowledgement goes to all dialysis and transplant centers for the work they had done already, and for the future efforts.