Table 2.

Association between lithium use and COVID-19 susceptibility

Study cohort	Lithium (n/N)	Control group (n/N)	Relative risk 95% CI
University of Pennsylvania Health System	33/435	46/435	0.71 [0.46–1.09]
Mount Sinai Medical Center	10/150	22/150	0.45 [0.22–0.92]
University of Iowa Health Care	50/670	120/670	0.42 [0.31–0.57]
Metaanalysis			0.51 [0.35–0.74]

Metaanalysis statistics: Test for random effect, z = −3.47, P = 0.005; test for heterogeneity, df = 2, P = 0.12, I² = 51.6%. N = Total number of patients in the cohort; n = number in group with outcome.