Table 2.

Hazard ratios (95% CI) of all-cause mortality associated with baseline serum calcium levels and various confounders in unadjusted and multivariable-adjusted Cox models

VariableUnadjusted ModelMultivariable-Adjusted Model
Baseline serum calcium
    <9.1 mg/dl (referent)1.01.0
    9.1 to 9.4 mg/dl0.88 (0.71, 1.10)1.16 (0.92, 1.46)
    9.41 to 9.7 mg/dl0.99 (0.80, 1.21)1.34 (1.08, 1.68)
    >9.7 mg/dl1.02 (0.83, 1.26)1.38 (1.11, 1.72)
Age, 1 yr older1.03 (1.02, 1.04)
Race, black versus white0.90 (0.74, 1.11)
CCI, 1 unit higher1.11 (1.05, 1.16)
DM versus no DM1.25 (1.05, 1.50)
ASCVD versus no ASCVD1.33 (1.12, 1.58)
SBP
    Linear term, 1 mmHg higher0.981 (0.960, 1.003)
    Quadratic term, 1 mmHg higher1.0001 (0.9999, 1.0002)
DBP, 1 mmHg higher0.999 (0.992, 1.006)
Active smoking versus nonsmoking1.57 (1.30, 1.89)
Calcitriol use versus no use0.46 (0.38, 0.56)
Calcium-based binder use versus no use0.93 (0.77, 1.13)
Sevelamer HCl use versus no use0.54 (0.40, 0.76)
Estimated GFR, 1 ml/min/1.73m2 higher0.986 (0.980, 0.991)
ALP, 1 U/L higher1.001 (0.999, 1.003)
Serum phosphorus, 1 mg/dl higher1.01 (0.91, 1.13)
Serum bicarbonate
    Linear term, 1 mEq/L higher0.76 (0.64, 0.94)
    Quadratic term, 1 mEq/L higher1.005 (1.001, 1.008)
Blood hemoglobin, 1 g/dl higher0.91 (0.86, 0.95)
WBC count, 1000/mm3 higher1.02 (0.98, 1.06)
Percent lymphocytes in WBC, 1% higher0.987 (0.976, 0.997)
24-h urine protein, 1 mg higher1.11 (1.04, 1.19)
Enrollment period
    1990 to 19950.64 (0.49, 0.84)
    1996 to 20000.91 (0.75, 1.11)
    2001 to 2007 (referent)1.0
  • DM, diabetes mellitus; ASCVD, atherosclerotic cardiovascular disease; SBP, systolic blood pressure; DBP, diastolic blood pressure; CCI, Charlson comorbidity index; ALP, alkaline phosphatase.