Dialysis, time and death: comparisons of two consecutive decades among patients treated at the same Brazilian dialysis center

Abstract

The survival of hemodialysis patients is likely to be influenced not only by well-known risk factors like age and comorbidity, but also by changes in dialysis technology and practices accumulated along time. We compared the survival curves, dialysis routines and some risk factors of two groups of patients admitted to a Brazilian maintenance hemodialysis program during two consecutive decades: March 1977 to December 1986 (group 1, N = 162) and January 1987 to June 1997 (group 2, N = 237). The median treatment time was 22 months (range 1-198). Survival curves were constructed using the Kaplan-Meier method and compared using the log-rank method. The Cox proportional hazard regression model was used to investigate the more important variables associated with outcome. The most important changes in dialysis routine and in patient care during the total period of observation were the progressive increase in the dose of dialysis delivered, the prohibition of potassium-free dialysate, the use of bicarbonate as a buffer and the upgrading of the dialysis equipment. There were no significant differences between the survival curves of the two groups. Survival rates at 1, 5 and 10 years were 84, 53 and 29%, respectively, for group 1 and 77, 42 and 21% for group 2. Patients in group 1 were younger (45.5 ± 15.2 vs 55.2 ± 15.9 years, P<0.001) and had a lower prevalence of diabetes (11.1 vs 27.4%, P<0.001) and of cardiovascular disease (9.3 vs 20.7%, P<0.001). According to the Cox multivariate model, only age (hazard ratio (HR) 1.04, confidence interval (CI) 1.03-1.05, P<0.001) and diabetes (HR 2.55, CI 1.82-3.58, P<0.001) were independent predictors of mortality for the whole group. Patients of group 2 had a lower prevalence of sudden death (19.1 vs 9.7%, P<0.001). After adjusting for age, diabetes and other mortality risk factors, the risk of death was 17% lower in group 2, although this difference was not statistically significant. We conclude that the negative effects of advanced age and of higher frequency of comorbidity on the survival of group 2 patients were probably offset by improvements in patient care and in the quality and dose of dialysis delivered, so that the survival curves did not undergo significant changes along time.

Estudo da sobrevida de pacientes submetidos a hemodiálise e estimativa de gastos no município de Ribeirão Preto-SP

“…Fizeram (6) Em estudo realizado com 399 pacientes renais crônicos na cidade de São Paulo, comparando duas décadas de tratamento dialítico, encontraram um tempo mediano de tratamento de 22 meses, superior portanto, ao encontrado em nosso estudo (7) Em estudo recente ( 8 ), 15% dos pacientes saíram de observação em função de transplantes, 3% pela recuperação da função renal (3%) e 44% por óbitos, tal percentual é bastante semelhante ao encontrado neste estudo.…”

“…A sobrevida de pacientes em hemodiálise é influenciada também pela tecnologia utilizada na diálise e a prática acumulada ao longo do tempo, nos serviços de TRS (7) .…”

“…Podemos entender que os pacientes estudados, em especial deste grupo etário, se adequadamente tratados, com acesso garantido às novas tecnologias terão uma permanência prolongada em tratamento dialítico (7)(8) Estudo da sobrevida de pacientes submetidos à hemodiálise... Chaves LDP, Anselmi ML, Barbeira CBS, Hayashida M.…”

“…Os efeitos negativos da idade avançada e elevada comorbidade podem ser compensados pelos cuidados ministrados aos pacientes, bem como pelo número, duração e qualidade das sessões de diálise, as quais podem melhorar a expectativa de vida deste grupo etário (7) .…”

"Acesso venoso central para hemodiálise: avaliação prospectiva da ocorrência de complicações"

“…Idade (anos) Ainda, a literatura nacional e internacional registra de que há predominância de Insuficiência Renal no sexo masculino (IWAMOTO, 1998;DE LIMA, 1999;ABUD, 2001;CHAVES, 2001;REIS, 2002;ROMÃO JÚNIOR, 2003;DACK et al, 2004;DI LORIO et al, 2004;LORENÇON et al, 2004, dentre outros Pesquisadores têm ostensivamente apontado a nefroesclerose hipertensiva como a principal causa da IRC (IANHEZ et al, 1996;D' AVILA et al,1999;ABUD, 2001;REIS, 2002, dentre outros).…”