Some older patients experienced extended survival when dialysis was initiated at higher levels of kidney function, according to a study published in the Journal of the American Society of Nephrology.
The main aim of the study was to evaluate the association between dialysis vs. medical management and survival at different ages and levels of kidney function, and the goal was to determine whether the association between dialysis initiation and survival was modified by age or estimated glomerular filtration rate (eGFR). Also, researchers wanted to estimate the median increase in survival with dialysis initiation compared with medical management at different ages and kidney function levels.
The researchers identified a 20% sample (n=73,349) of U.S. veterans with eGFR of less than 30 ml/min per 1.73 m2 between 2005 and 2010. Investigators conducted follow-up through 2012. The researchers used an extended Cox model to study the associations among the time-varying exposures, age, eGFR, provision of dialysis and survival.
During a mean follow-up of 3.4 years, investigators found 15% of patients started dialysis and 52% of patients died.
For patients on dialysis who were aged younger than 65, aged 65 to 75, aged 75 to 84 and 85 years and older, lower mortality was associated with eGFR not exceeding 6 to less than 9, less than 6, 9 to less than 12 and 9 to less than 12 ml/min per 1.73m2, respectively. When dialysis was initiated at eGFR of less than 6 ml/min per 1.73 m2, patients had a greater median life expectancy of 25, 26 and 19 months for patients aged 65, 75 and 85 years, respectively.
“The eGFR at which dialysis, compared with medical management, associated with lower mortality varied by age,” the researchers wrote.
The authors report no relevant financial disclosures.