Table 3

Multilevel models predicting adjuvant chemotherapy for stages III colon and II/III rectal cancers in Georgia, USA, 2000–2004

Model 1Model 2Model 3Model 4
Measures of association (OR, 95% CI)
Individual level variables
 Women (vs men)0.97 (0.85 to 1.10)0.97 (0.85 to 1.10)0.97 (0.85 to 1.10)
 Age (≥80 vs 15–54)0.08 (0.06 to 0.10)*0.08 (0.06 to 0.10)*0.08 (0.06 to 0.10)*
 Age (75–79 vs 15–54)0.29 (0.24 to 0.37)*0.29 (0.24 to 0.37)*0.29 (0.23 to 0.36)*
 Age (70–74 vs 15–54)0.47 (0.38 to 0.59)*0.48 (0.39 to 0.59)*0.48 (0.39 to 0.59)*
 Age (65–69 vs 15–54)0.70 (0.57 to 0.87)*0.71 (0.57 to 0.87)*0.71 (0.58 to 0.87)*
 Age (55–64 vs 15–54)0.86 (0.72 to 1.03)**0.86 (0.71 to 1.03)**0.86 (0.72 to 1.03)**
 Colon (vs rectum)0.68 (0.59 to 0.78)*0.68 (0.60 to 0.78)*0.68 (0.59 to 0.78)*
 Black (vs white)0.83 (0.71 to 0.96)*0.85 (0.71 to 1.00)**
Tract level variables
 ≥20% (vs <5% BPL)0.75 (0.58 to 0.97)*1.00 (0.75 to 1.31)1.02 (0.77 to 1.34)
 10–19.9% (vs <5% BPL)0.81 (0.66 to 1.00)**0.94 (0.75 to 1.17)0.97 (0.77 to 1.21)
 5–9.9% (vs <5% BPL)0.77 (0.63 to 0.95)*0.86 (0.69 to 1.07)0.87 (0.70 to 1.09)
 High (vs low % black)1.02 (0.84 to 1.23)0.93 (0.75 to 1.15)0.94 (0.76 to 1.16)
 Moderate (vs low % black)0.99 (0.84 to 1.17)0.95 (0.79 to 1.13)0.94 (0.79 to 1.12)
 Urban (vs rural)1.09 (0.90 to 1.32)1.19 (0.97 to 1.47)**1.38 (1.09 to 1.74)*
 Suburban (vs rural)1.38 (1.12 to 1.68)*1.37 (1.10 to 1.70)*1.53 (1.20 to 1.94)*
Cross level interactions
 Urban (Black vs White)0.76 (0.62 to 0.94)*
 Suburban (Black vs White)0.81 (0.58 to 1.13)
 Rural (Black vs White)1.32 (0.90 to 1.93)
Measures of variation or clustering
 Tract level variance (SE)0.145 (0.047)*0.162 (0.053)*0.156 (0.053)*0.151 (0.053)*
 MOR1.471.441.451.44
 ICC0.0470.0430.0450.043
  • BPL, below poverty line; MOR, median odds ratio; ICC, intraclass correlation coefficient.

  • *p<0.05; **p<0.1.