Table 2. Power and type I error rates of alternative methods at different sample sizes.
| Sample size | 300 | 400 | 500 | 600 | 700 | 800 | 900 | 1000 | |
|---|---|---|---|---|---|---|---|---|---|
| Power | Logistic | 2.5% | 4.0% | 8.6% | 12.4% | 14.0% | 17.7% | 21.5% | 29.1% |
| Chi-squared | 1.7% | 2.2% | 5.7% | 18.9% | 25.0% | 37.8% | 42.1% | 44.7% | |
| MDR | 2.1% | 6.3% | 14.5% | 36.0% | 47.1% | 63.3% | 67.9% | 71.8% | |
| W | 16.0% | 28.8% | 38.5% | 67.8% | 72.8% | 82.2% | 83.2% | 83.8% | |
| Type I Error Rate | Logistic | 4.1E−05 | 4.9E−05 | 3.9E−05 | 5.0E−05 | 4.4E−05 | 4.3E−05 | 4.6E−05 | 4.7E−05 |
| Chi-squared | 2.0E−06 | 2.0E−06 | 1.0E−06 | 0 | 3.0E−06 | 4.0E−06 | 0 | 2.0E−06 | |
| MDR | 0 | 7.0E−06 | 1.4E−05 | 2.0E−05 | 2.8E−05 | 3.4E−05 | 6.5E−05 | 6.1E−05 | |
| W | 5.5E−05 | 4.9E−05 | 4.6E−05 | 4.6E−05 | 4.1E−05 | 4.4E−05 | 4.3E−05 | 4.2E−05 |
The simulation study is performed using a non-linear genetic model, 1%< MAF < 5%, and medium LD genetic architectures. As the sample size decreases, the W-test showed persistent better power and reasonable type I error rates.