Table 2

Parsimonious polynomial model versus patient characteristics model variables

Predictor variablesPolynomial modelPatient characteristics model
OR (95% CI)P valuesβ coefficientOR (95% CI)P valuesβ coefficient
Model constantN/AN/A−28.15N/AN/A−10.44
Age, per year1.79 (0.88 to 3.93)0.1100.58451.06 (1.02 to 1.11)0.0050.05895
Age2, per year2 1.00 (0.99 to 1.00)0.158−0.004026N/AN/AN/A
Gender, femaleN/AN/AN/A
Lung cancer in family
Prior diagnosis of cancer1.74 (0.88 to 3.02)0.0620.55551.67 (0.84 to 2.87)0.0820.5131
Smoking status, active1.66 (1.22 to 2.28)0.0010.5046
Pack-years, per pack-year1.04 (1.02 to 1.07)<0.0010.039221.01 (1.00 to 1.01)0.0010.008342
Pack-years2, per pack-year2 1.00 (1.00 to 1.00)0.013−1.632×10–4 N/AN/AN/A
Smoking duration, per year1.03 (1.00 to 1.07)0.0680.03260
Quit duration, per year0.96 (0.92 to 1.01)0.103−0.03875
Prior diagnosis of COPD1.51 (0.85 to 2.46)0.1100.41441.69 (0.96 to 2.71)0.0380.5263
Prior diagnosis of pneumoniaN/AN/AN/A
Occupational exposure to asbestos1.51 (0.78 to 2.56).1490.4137
Emphysema on scanN/AN/AN/A
Longest nodule diameter, per mmN/AN/AN/A
Longest perpendicular diameter, per mm1.11 (1.06 to 1.15)<0.0010.09962N/AN/AN/A
Longest perpendicular diameter2, per mm2 1.00 (1.00 to 1.00)0.015−6.524×10–4 N/AN/AN/A
Presence of non-solid nodule1.52 (0.92 to 2.42)0.0770.4217N/AN/AN/A
Presence of part solid nodule2.49 (1.36 to 4.21)0.0010.9108N/AN/AN/A
Presence of nodule in upper lobe1.60 (1.05 to 2.39)0.0210.4685N/AN/AN/A
Presence of spiculated nodule2.12 (1.29 to 3.37)0.0020.7512N/AN/AN/A
Nodule count per scan, per additional nodule1.67 (0.99 to 2.98)0.0490.5128N/AN/AN/A
Nodule count per scan2, per additional nodule2 0.82 (0.66 to 0.97)0.019−0.1947N/AN/AN/A
  • The small dash signifies that the variable was included in the initial regression analysis but not in the final model and thus does not have a value in the equation.

  • N/A, not applicable (was not included in the initial regression analysis).