Table 1

Bias factors calculated under different hypothetical variation in cancer incidence rates and high-risk genotype frequencya

Risk ratiobFrequency of at-risk genotypecBias factor among all 28 subsets of size 2 among the eight groupsBias factor among all 40,320 orderings of the eight groups
MaxMinMaxMinMaxMin2.5 %ile5 %ile10 %ile25 %ile50 %ile75 %ile90 %ile95 %ile97.5 %ileMax biasMean bias
1.00.10.31.001.001.001.001.001.001.001.001.001.001.001.001.001.00
1.00.20.51.001.001.001.001.001.001.001.001.001.001.001.001.001.00
1.00.30.91.001.001.001.001.001.001.001.001.001.001.001.001.001.00
1.10.10.30.971.030.990.990.990.991.001.001.001.011.011.011.011.00
1.10.20.50.971.030.990.990.990.991.001.001.001.011.011.011.011.00
1.10.30.90.941.060.970.980.980.990.991.001.011.011.021.021.031.00
1.20.10.30.941.060.980.980.980.990.991.001.011.011.021.021.021.00
1.20.20.50.941.060.970.980.980.990.991.001.011.011.021.021.031.00
1.20.30.90.891.120.950.970.970.980.991.001.011.021.031.041.051.00
1.30.10.30.921.080.970.980.980.980.991.001.011.021.021.031.041.00
1.30.20.50.921.090.960.970.980.980.991.001.011.021.021.031.041.00
1.30.30.90.851.180.930.950.960.970.981.001.021.041.041.051.071.00
1.40.10.30.901.110.960.970.970.980.991.001.011.021.031.031.051.00
1.40.20.50.891.110.950.970.970.980.991.001.011.021.031.031.051.00
1.40.30.90.811.240.920.940.950.960.971.001.031.051.061.071.091.00
1.50.10.30.881.130.950.960.970.970.981.001.021.031.031.041.051.00
1.50.20.50.871.140.940.960.970.970.981.001.021.031.041.041.061.00
1.50.30.90.781.290.900.930.940.950.971.001.031.061.071.081.111.00
1.60.10.30.861.150.940.960.960.970.981.001.021.031.041.041.061.00
1.60.20.50.861.160.940.950.960.970.981.001.021.031.041.051.071.00
1.60.30.90.751.350.880.920.930.940.971.001.041.061.081.091.131.00
1.70.10.30.841.170.930.950.960.970.981.001.021.031.041.051.071.00
1.70.20.50.841.180.930.950.960.960.981.001.021.041.051.051.081.00
1.70.30.90.731.400.870.910.920.930.961.001.041.071.091.111.151.00
1.80.10.30.831.190.920.950.950.960.981.001.021.041.051.061.081.00
1.80.20.50.821.200.920.940.950.960.981.001.021.041.051.061.081.00
1.80.30.90.711.450.860.900.910.930.961.001.041.081.101.121.171.00
1.90.10.30.811.200.920.940.950.960.981.001.021.041.051.061.081.00
1.90.20.50.811.220.910.940.950.960.981.001.031.041.061.061.091.00
1.90.30.90.691.510.850.890.900.920.951.001.051.091.111.131.181.00
2.00.10.30.801.220.910.940.950.960.971.001.031.051.061.061.091.00
2.00.20.50.801.240.910.930.940.950.971.001.031.051.061.071.101.00
2.00.30.90.671.560.840.880.900.920.951.001.051.091.121.141.201.00
2.10.10.30.791.230.910.930.940.950.971.001.031.051.061.071.101.00
2.10.20.50.781.250.900.930.940.950.971.001.031.051.061.071.101.00
2.10.30.90.651.600.830.870.890.910.951.001.061.101.131.151.211.00
2.20.10.30.781.250.900.930.940.950.971.001.031.051.061.071.101.00
2.20.20.50.771.270.900.930.940.950.971.001.031.051.071.081.111.00
2.20.30.90.631.650.820.870.880.910.941.001.061.111.131.161.231.00
2.30.10.30.771.260.900.930.940.950.971.001.031.051.071.081.111.00
2.30.20.50.761.290.890.920.930.950.971.001.031.061.071.081.121.00
2.30.30.90.621.700.810.860.880.900.941.001.061.111.141.171.241.00
2.40.10.30.761.270.890.920.930.950.971.001.031.061.071.081.111.00
2.40.20.50.751.300.890.920.930.940.971.001.031.061.071.091.121.00
2.40.30.90.611.740.810.860.870.900.941.001.071.121.151.171.251.00
2.50.10.30.751.280.890.920.930.940.971.001.031.061.071.081.121.00
2.50.20.50.741.310.880.920.930.940.971.001.041.061.081.091.131.00
2.50.30.90.591.790.800.850.870.890.941.001.071.121.161.181.271.00
  • a The table entries are confounding risk ratios, calculated according to the formula provided by Wacholder et al. (2) . They show the bias factor when there are two or eight equally common ethnic groups in the population, and no attempt has been made to adjust for ethnicity or other risk factors.

  • b Ratio of the highest to the lowest risk of disease in the eight ethnic groups. The eight rates are spaced equidistantly on a linear scale.

  • c Minimum and maximum frequency of at-risk genotype in the eight ethnic groups. The eight frequencies are spaced equidistantly on a linear scale.