Table 2.

Incidence rates and adjusted IRR for infectious events by baseline phosphate levela

Type of InfectionIncidence Rate, Per 1000 Patient-YearsIRR (95% CI)
Unadjusted+Demographics+Clinical+Laboratory
All (mg/dl)n = 1008bn = 1008n = 947n = 935
    <3.53140.91 (0.71 to 1.16)0.88 (0.69 to 1.13)0.72 (0.55 to 0.96)c0.61 (0.46 to 0.82)c
    3.5 to 5.53991.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
    >5.54801.19 (1.06 to 1.33)c1.24 (1.10 to 1.39)c1.22 (1.09 to 1.38)c1.28 (1.12 to 1.45)c
    P for trend0.003c0.001c0.002c0.001c
Sepsis (mg/dl)n = 972bn = 972n = 911n = 902
    <3.5290.67 (0.31 to 1.46)0.62 (0.29 to 1.36)0.61 (0.28 to 1.34)0.61 (0.28 to 1.36)
    3.5 to 5.5731.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
    >5.5861.14 (0.88 to 1.48)1.29 (0.98 to 1.70)1.39 (1.05 to 1.85)c1.44 (1.07 to 1.95)c
    P for trend0.3440.0830.032c0.027c
Respiratory tract (mg/dl)n = 995bn = 995n = 928n = 916
    <3.5940.90 (0.58 to 1.40)0.88 (0.56 to 1.37)0.80 (0.49 to 1.31)0.81 (0.49 to 1.32)
    3.5 to 5.51161.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
    >5.51241.03 (0.83 to 1.28)1.12 (0.90 to 1.40)1.05 (0.84 to 1.32)1.08 (0.85 to 1.38)
    P for trend0.7960.3320.7500.599
Osteomyelitis (mg/dl)n = 809bn = 809n = 758n = 749
    <3.580.46 (0.10 to 1.96)0.46 (0.11 to 1.94)dd
    3.5 to 5.5211.00 (reference)1.00 (reference)1.00 (reference)1.00 (reference)
    >5.5341.59 (1.02 to 2.48)c1.73 (1.09 to 2.75)c1.68 (1.04 to 2.72)c1.73 (1.05 to 2.86)c
    P for trend0.046c0.029c0.0650.081
  • a Demographics: age, gender, race; clinical: modality, ICED, smoking status; laboratory: albumin, creatinine, hemoglobin. Total number of nonfatal infections was 1398; sepsis infections, 246; respiratory tract infections, 389; osteomyelitis, 82. CI, confidence interval.

  • b Observations in groups with no variation in outcome dropped in conditional modeling.

  • c P < 0.05.

  • d No estimate because of small cell sizes.