In dialysis patients, one answer predicts mortality.

SAN FRANCISCO -- If a person on dialysis answers "poor" to the question, "How would you say your health is in general?" the risk of death is four times that of people who answer "excellent" or "very good."

That's the result of a prospective cohort study that Melissa Thong of Leiden (the Netherlands) University Medical Center and her colleagues presented as a poster at the annual meeting of the American Society of Nephrology.

The investigators wrote that this single self-rated health question can be a "useful complement to clinical measures in risk assessment and promotion of better health outcomes for patients."

The study participants included 825 patients under the age of 65 years and 618 patients aged 65 or older; all were on either hemodialysis or peritoneal dialysis. All participants were at least 18 years old when they began dialysis at one of 38 Dutch dialysis centers between 1997 and 2004. They were followed until death, transplantation, withdrawal, or the end of the study on Jan. 1, 2005.

When asked the general health question, patients could answer "excellent," "very good," "good," "fair," or "poor." The investigators combined those who answered "excellent" and "very good" into one group because relatively few patients placed themselves in those categories.

Compared with the patients who judged their general health to be excellent or very good, those who judged their general health to be fair had a hazard ratio for mortality of 2.17, and those who judged their general health to be poor had a hazard ratio of 3.93. These results were statistically significant and were adjusted for age, sex, marital status, education, primary kidney disease, comorbidity, treatment modality, serum albumin, body mass index, nutritional status, residual glomerular filtration rate, and smoking.

In patients under 65, the unadjusted mortality rate was 1.8/100 years in those who rated their health as very good, compared with 23.2/100 years for those who rated their health as poor. Similarly, among patients 65 or older, mortality was 12.0/100 years for those who rated their health as very good, vs. 36.5/100 years for those who judged their health to be poor.

BY ROBERT FINN

San Francisco Bureau