Table 2 Performance evaluation criteria
Simulation study 1 | Evaluation criteria (covariate j = 1, 2, 3 and sample m = 1, …, 100) |
|---|---|
Mean relative bias | \(\frac{\sum_{j=1}^3\sum_{m=1}^{100}\frac{\left|{\hat{\beta}}_{jm}-{\beta}_j\right|}{\beta_j}\times 100}{3\times 100}\) |
Average length of 95%CI | \(\frac{\sum_{j=1}^3\sum_{m=1}^{100}2{Z}_{1-\alpha /2} SE\left({\hat{\beta}}_{jm}\right)}{3\times 100}\) |
Coverage | Percentage of times the 95% confidence interval \({\hat{\beta}}_{jm}\pm {Z}_{1-\alpha /2} SE\left({\hat{\beta}}_{jm}\right)\) includes βj |
Simulation study 2 | Evaluation criterium |
Type I error | Percentage of times the H0:β = 0 is rejected, for m = 1, …, 1000 |