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
| Variable | Unadjusted Model | Multivariable-Adjusted Model |
|---|---|---|
| Baseline serum calcium | ||
| <9.1 mg/dl (referent) | 1.0 | 1.0 |
| 9.1 to 9.4 mg/dl | 0.88 (0.71, 1.10) | 1.16 (0.92, 1.46) |
| 9.41 to 9.7 mg/dl | 0.99 (0.80, 1.21) | 1.34 (1.08, 1.68) |
| >9.7 mg/dl | 1.02 (0.83, 1.26) | 1.38 (1.11, 1.72) |
| Age, 1 yr older | 1.03 (1.02, 1.04) | |
| Race, black versus white | 0.90 (0.74, 1.11) | |
| CCI, 1 unit higher | 1.11 (1.05, 1.16) | |
| DM versus no DM | 1.25 (1.05, 1.50) | |
| ASCVD versus no ASCVD | 1.33 (1.12, 1.58) | |
| SBP | ||
| Linear term, 1 mmHg higher | 0.981 (0.960, 1.003) | |
| Quadratic term, 1 mmHg higher | 1.0001 (0.9999, 1.0002) | |
| DBP, 1 mmHg higher | 0.999 (0.992, 1.006) | |
| Active smoking versus nonsmoking | 1.57 (1.30, 1.89) | |
| Calcitriol use versus no use | 0.46 (0.38, 0.56) | |
| Calcium-based binder use versus no use | 0.93 (0.77, 1.13) | |
| Sevelamer HCl use versus no use | 0.54 (0.40, 0.76) | |
| Estimated GFR, 1 ml/min/1.73m2 higher | 0.986 (0.980, 0.991) | |
| ALP, 1 U/L higher | 1.001 (0.999, 1.003) | |
| Serum phosphorus, 1 mg/dl higher | 1.01 (0.91, 1.13) | |
| Serum bicarbonate | ||
| Linear term, 1 mEq/L higher | 0.76 (0.64, 0.94) | |
| Quadratic term, 1 mEq/L higher | 1.005 (1.001, 1.008) | |
| Blood hemoglobin, 1 g/dl higher | 0.91 (0.86, 0.95) | |
| WBC count, 1000/mm3 higher | 1.02 (0.98, 1.06) | |
| Percent lymphocytes in WBC, 1% higher | 0.987 (0.976, 0.997) | |
| 24-h urine protein, 1 mg higher | 1.11 (1.04, 1.19) | |
| Enrollment period | ||
| 1990 to 1995 | 0.64 (0.49, 0.84) | |
| 1996 to 2000 | 0.91 (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.