The hidden link—Serum calcium levels and readmission risk in heart failure patients: A retrospective cohort study

The relationship between serum calcium and readmission within 6 months in patients with heart failure (HF) is currently unknown. Therefore, we aimed to investigate whether serum calcium was independently related to readmission within 6 months in patients with HF after adjusting for other covariates. A total of 2008 patients who underwent HF were enrolled to determine the relationship between serum calcium levels and readmission within 6 months. Participants were divided into 2 categories based on serum calcium quartiles. The relationships between serum calcium and readmission within 6 months were analyzed via multivariable logistic regression models. The results of the multivariable logistic regression analysis showed that serum calcium at baseline increased the risk of readmission within 6 months after confounders were adjusted (odds ratio = 2.49, 95% confidence interval: 1.27-4.87). Moreover, when serum calcium was transformed into a categorical variable and the first quartile was used as a reference, the odds ratios and 95% confidence intervals of the second to fourth quartiles were 1.26 (0.93-1.7), 1.38 (1.0-1.9), and 1.55 (1.11-2.17), respectively, with a P-value for trend of .012. Furthermore, curve fitting revealed that serum calcium and readmission within 6 months were linearly related. Serum calcium is positively associated with readmission within 6 months in patients with HF, and the relationship between these factors is linear.