New Risk Tool Helps Predict Short-Term Mortality in Elderly who Start Dialysis

A clinical risk prediction tool based on readily available data performs well in identifying older adults at high risk of death within 6 months after dialysis initiation, reports a study in the American Journal of Kidney Diseases.

It is generally accepted that older adults are at increased risk of death and other adverse outcomes in the months after starting dialysis. The investigators wanted to investigate whether a clinical risk prediction tool that takes into account the characteristics of older adults with kidney failure might help to inform the decision to initiate maintenance dialysis.

Using renal registry data from Alberta, Canada, the investigators identified 2199 patients aged 65 or older who initiated maintenance dialysis therapy between 2003 and 2012. Patients with acute kidney injury were excluded. A wide range of clinical and laboratory factors were evaluated as potential predictors of all-cause mortality within 6 months after the start of dialysis. The model was derived using data from the full cohort of patients. Internal validation was performed using the tenfold cross-validation sample use-reuse method.

The mean age for patients in the study was 75.2 years, and about 61% of those were men. Six months after dialysis initiation, all-cause mortality was 17.1%.

Seven predictors were included in the final model and incorporated into a 19-point scoring system: age 80 or older (2 points), estimated glomerular filtration rate of 10 to 14.9 mL/min/1.73 m2 (1 point) or 15 mL/min/1.73 m2 or higher (3 points), atrial fibrillation (2 points), lymphoma (5 points), congestive heart failure (2 points), hospitalization within 6 months (2 points), and metastatic cancer (3 points).

Patients who had higher scores on these predictors were generally at higher risk of death. The six-month mortality was less than 25% for patients with scores of less than 5, but more than 50% for those with scores of greater than 12.

The researchers concluded that the 19-point clinical decision tool evaluated in their study may predict early mortality after initiation of dialysis in older adults, but that the tool has yet to be externally validated.

An editorial that accompanied the research raised some questions to consider when deciding whether to incorporate this clinical decision tool or previously developed risk scores into clinical practice—including “whether the score accurately predicts outcomes in people like their patients.”

The editorial authors noted the need for prospective studies of factors affecting outcomes in older adults with chronic kidney failure. Such studies should include patients who choose a “supportive pathway,” rather than just those who initiate dialysis, they said.

References

1. Wick JP, et al. A clinical risk prediction tool for 6-month mortality after dialysis initiation among older adults. Am J Kidney Dis 2017; 69:568–575; Foote C, et al. Scoring risk scores: considerations before incorporating clinical risk prediction tools into your practice. Am J Kidney Dis 2017; 69:555–557].