Early Dialysis Starts Associated with Worse Outcomes
ST. JOHN'S, NEWFOUNDLAND—Recent study findings add to mounting evidence of the deleterious consequences of early dialysis initiation, prompting researchers to question this approach, especially among older patients.
Investigators documented a doubling of the withdrawal rate from 1.5 to 3.0 per 100 patient-years of dialysis in the Canadian Organ Replacement Registry (CORR) from 2001 and 2009. Each 10-year increase in age was associated with an 84% greater likelihood of withdrawal, and early-start dialysis is associated with a 15% greater probability of withdrawal than late starts. Meanwhile, the researchers observed a sharp rise in the proportion of deaths due to withdrawal among deceased dialysis patients, from 7.9% in 2001 to 19.5% in 2009.
“More and more patients are starting dialysis early, especially elderly patients, with higher residual renal function, and then a lot of them go on to just withdraw,” said Amanda Ellwood, MD, who led the study while she was completing her nephrology fellowship at the University of Western Ontario in London. “So the question is, should we be starting them on dialysis or should we be considering another approach, such as multidisciplinary conservative management?”
Working under Louise Moist, MD, Associate Professor of Nephrology at the university, and in conjunction with other researchers, Dr. Ellwood examined CORR data from 2001-2009. They focused on patients who started dialysis in that period.
The 3,339 patients who withdrew from dialysis and the 42,842 who did not had divergent demographic and medical characteristics. For example, the mean age of those who stopped dialysis was 73.2 years compared with 63 years for those who remained on dialysis, with 51.5% and 26.9% of the two groups, respectively, aged 75 or older. Furthermore, 39.8% of the withdrawal subjects had early dialysis initiation compared with 34.4% in the no-withdrawal group. The only statistically significant similarities between the two groups were their rates of hypertension and diabetes, at about 80% and 45%, respectively.
Overall, the median time to withdrawal was 15.9 months and 15.6 months for patients aged 75 and older and those with early-start dialysis, respectively. The respective median times for patients with late-start dialysis and those younger than 75 years were 20.2 and 21.6 months.
Dr. Ellwood's group also found that factors most significantly associated with withdrawal were increased age, early versus late dialysis initiation, late versus early referral to a nephrologist, initiating dialysis from 2006-2009 rather than 2001-2005, and starting dialysis in Nova Scotia (compared with Ontario, the reference province).
Factors associated with not withdrawing from dialysis were being male, being black or native Indian rather than white, and starting dialysis in Alberta, British Columbia, or New Brunswick.
Dr. Ellwood presented these results at the 2012 annual meeting of the Canadian Society of Nephrologists. One of the audience members asked whether the results with respect to early initiation could have been confounded by the emaciated state—and hence falsely low creatinine levels—among many patients with end-stage renal disease. Dr. Elwood agreed that this may have been a confounding factor and that they were not able to correct for this in their analysis because virtually all methods for calculating glomerular filtration rate include creatinine levels.
She added that two other limitations were that CORR is a voluntary database and under-or over-reporting may affect results, and that dates of death were not available for approximately 25% of the patients in the analysis.