Admission hyponatremia in the elderly: factors influencing prognosis.

The authors studied the occurrence of admission hyponatremia and its association with selected patient and hospitalization characteristics and in-hospital mortality in a geriatric patient cohort (n = 4,123). Prevalence of admission hyponatremia was 3.5% and higher among women (4.6% vs 2.6%). In-hospital mortality was 16% for patients with admission hyponatremia versus 8.0% for patients without admission, hyponatremia. Adjusting for patient and hospitalization characteristics with a logistic regression analysis, admission hyponatremia was a significant independent predictor of mortality (RR = 1.95). Admission hyponatremia is associated with poor prognosis in the elderly hospitalized population.