[Chronic dialysis in Uruguay: mortality trends from 1981 to 1998]]

Uruguay is a developing country with 3.16 million inhabitants. Chronic dialysis treatment (CDT) expanded after the creation of a National Fund of Resources in 1980 who receives contribution from all inhabitants to finance, among others, the CDT and renal transplantation. During the 1981-1998 period, about 4,819 patients were treatment, 2,365 patients had died, 454 were transplanted and 51 patients were lost to follow-up due to change in residence. At the start of the treatment, mean age was 57.0 +/- 17.7 years, 37% were 65 or older than 65 year old, 61.3% were male and 98% of patients were white persons. The most common diseases responsible for End Stage Renal Disease were: hypertension (22%), chronic glomerulonephritis (19%) and diabetic nephropathy (15%). In 1998, there were 44 dialysis units in the country (13.6 units per million population--pmp), 100% of them had water treatment (reverse osmosis 96.8%) and reuse dialyzer. The most frequent causes of death were: cardiovascular and infection. In this paper, eighteen years of the mortality time course of CDT are analyzed. Annual mortality rate was expressed as deaths per 1,000 patients years at risk (M/1,000). The indirect standardization method was applied to adjust the mortality rate. Two populations were used as standard: the 1996 population of USRDS to adjust for age, sex, race and nephropathy and the 1996 Uruguayan general population to adjust for age. Standardized mortality rate (SMR) for each year was obtained dividing observed deaths by expected deaths. From 1981 to 1998, the incident population increased from 32 to 133 patients per million populations and the prevalent population from 28 to 639 pmp. There was a simultaneously increase in the prevalence of diabetic patients and of patients older than 65 years. The annual mortality rate decreased from 249 to 138 deaths per 1,000 patient years (M/1,000). The standardized mortality (SM) with the USRDS population as standard decreased from 452 in 1981 to 132 in 1998 and the SMR from 2.07 to 0.60. The SMR with the Uruguayan general population decreased from 17 to 4. In conclusion, these results are similar with those observed in developed countries. There has been a decrease both in the gross and the standardized mortality ratio in the period of observation.