Table 6 Hyponatremia and cognitive impairment: strength of association according to Bradford Hill’s criteria

Chung et al. (2017) [48]

HR 2.36 (2.09–2.66)

 < 0.001

C. Fujisawa et al. (2021) [49]

OR 1.1 (0.7–1.9)

0.7

Gosch et al. (2012) [13]

OR 1.96 (1.05–4.19)

0.036

Pereira et al. (2006) [50]

Not reported

Not reported

Suárez et al. (2020) [51]

OR 3.13 (0.54–25.86) in moderate hyponatremia, OR 8.55 (1.63–72.73) in moderate to profound hyponatremia

0.227

0.022