Table 4.

Effects of hyponatremia and hypernatremia on total direct medical costsa

CostsEffect of HyponatremiaEffect of Hypernatremia
Univariate ModelMultivariable ModelbUnivariate ModelMultivariable Modelb
6 mo
    medical costs98.8 (80.4 to 119.2)41.2 (30.3 to 53.0)16.5 (7.5 to 26.3)5.4 (−1.4 to 12.6)
    inpatient costs only175.4 (136.3 to 221.0)76.4 (55.0 to 100.7)39.7 (21.9 to 60.1)18.5 (5.7 to 32.9)
1 yr
    medical costs107.6 (87.2 to 130.1)45.7 (34.2 to 58.2)18.5 (8.7 to 29.2)6.3 (−0.8 to 13.8)
    inpatient costs only206.7 (163.3 to 257.3)95.6 (73.3 to 120.8)37.4 (19.0 to 58.7)14.7 (2.4 to 28.5)
  • a Values are expressed as the estimated percent change in costs (95% confidence interval).

  • b The multivariable model controlled for age, sex, geographic region, underlying and comorbid conditions, and medications known to cause hyponatremia.