Fig. 3

a The comparison between the vaptans groups and placebo groups about the mean of baseline serum sodium concentration before interventions. Studies are identified by the first author’s name and year of publication. Weighted mean differences are pooled using the fixed effects model. Abbreviation: SD, standard deviation; CI, confidence interval. b The comparison between the vaptans groups and placebo groups about the mean of ending serum sodium concentration after short-term (1-14d) interventions. Studies are identified by the first author’s name and year of publication. Weighted mean differences are pooled using the random effects model. Abbreviation: SD, standard deviation; CI, confidence interval. c The comparison between the vaptans groups and placebo groups about the mean change of serum sodium concentration after 7 days interventions. Studies are identified by the first author’s name and year of publication. Weighted mean differences are pooled using the random effects model. Abbreviation: SD, standard deviation; CI, confidence interval. d The comparison between the vaptans groups and placebo groups about the normalization ratio of serum sodium concentration within 1 week (4, 5, 7d) interventions. Studies are identified by the first author’s name and year of publication. The Odds Ratios are pooled using the fixed effects model. Abbreviation: CI, confidence interval