Background: Hyponatremia is the most prevalent electrolyte disorder in hospitalized adult medical patients and is associated with a significant healthcare resource burden. However, evidence remains scarce whether hyponatremia is a marker of disease severity or whether it has an independent effect on clinical outcomes.
Methods: In this nationwide cohort study, we analyzed medical inpatients with hyponatremia diagnosed between January 2009 through December 2015 using prospective administrative data. Hyponatremia patients were matched (1:1) to a non-hyponatremia cohort using propensity score matching. We used multivariate regressions models to assess differences in in-hospital mortality, intensive care unit (ICU) admission, length of hospital stay, and 30-day readmission rates.
Results: Among 2,426,722 medical inpatients, 83,871 (3.5%) were diagnosed with hyponatremia and propensity-matched with 83,871 patients without hyponatremia. We found no difference for in-hospital mortality (odds ratio [OR] 1.02, 95% confidence interval [95% CI]: 0.971.06, P=0.459), however a higher risk for ICU admission (OR 1.19, 95% CI: 1.151.22, P<0.001). The diagnosis of hyponatremia was associated with a prolonged length of hospital stay by 1.37 days (95% CI: 1.281.47, P<0.001). 30-day readmission rates were not significantly different between both groups (OR 1.02, 95% CI: 0.991.05, P=0.170).
Conclusion: Hyponatremia is an independent risk factor for increased ICU admission and length of hospital stay and therefore represents a potential target for intervention to reduce healthcare burden for a large population of hospitalized hyponatremic patients.
18 - 21 May 2019
European Society of Endocrinology