Table 3.
Empirical sizes of the proposed spline-based nominal 0.05-level tests for covariate effects of Si in the model λ(t|Si) = λ0(t) (no effect) and λ(t|Si) = λ0(t) exp{Si} (linear effect), i = 1, 2, . . . , n, expressed as percent. λ0(t) = 1; values of Si are as in Table 1. Results are based on 2000 simulations for each scenario. The binomial (N = 2000, p = 0.05) standard error for the entries is 0:49%.
| Null hypothesis
|
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|---|---|---|---|---|---|
|
n = 100
|
n = 200
|
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| Censoring distribution | Number of distinct covariate values | No effect | Linear effect | No effect | Linear effect |
| Unit exponential | 4 | 5.25 | 4.65 | 5.10 | 4.90 |
| 10 | 5.20 | 4.35 | 5.00 | 4.60 | |
| 20 | 5.15 | 4.60 | 5.05 | 4.50 | |
| 50 | 5.05 | 4.45 | 4.95 | 4.60 | |
| 100 | 5.15 | 4.25 | 5.00 | 4.80 | |
| 200 | 4.95 | 4.70 | |||
| Uniform (0,1.5) | 4 | 4.90 | 4.80 | 4.50 | 4.65 |
| 10 | 5.30 | 5.15 | 5.10 | 5.05 | |
| 20 | 5.00 | 5.50 | 4.60 | 4.90 | |
| 50 | 5.05 | 5.60 | 4.50 | 4.95 | |
| 100 | 5.00 | 5.70 | 4.70 | 4.95 | |
| 200 | 4.70 | 4.85 | |||