Table 2.

Performance of the polytomous model estimates [Embedded Image and Embedded Image in Eq. (2)] of OR2 and Embedded Image and Embedded Image

ScenarioEvent 2Comparison
OR2Embedded ImageEmbedded Image
BiasaCoverageBiasCoveragePower/type I errorBiasCoveragePower/type I error
(a)1.595.61.595.64.42.494.878.8
(b)0.695.81.395.659.62.096.23.8
(c)4.694.24.694.25.8−0.197.873.2
(d)2.294.66.392.286.4−0.097.03.0
(e)0.196.60.196.63.45.395.487.8
(f)−0.495.21.896.494.25.695.44.6
(g)2.994.02.994.06.04.396.299.6
(h)2.694.412.379.499.88.896.43.6

NOTE: Scenarios considered for event 1 are also considered for event 2, that is, both events include the scenarios of positive associations with the exposure and null associations with the exposure. For the same scenario, the results for event 2 are similar to those for event 1. Therefore, for simplicity, in Tables 2 and 3, we omit the result for event 1 and only report for results on parameters associated with event 2 and parameters associated with the contrast between events 1 and 2.

  • aBias is defined as (estimated value-parameter of interest)/parameter of interest × 100; coverage is the percentage of times the CI included the parameter of interest; power is the percentage of times the CI did not include 1 when the alternative is true and type I error rate is the same percentage but when the null is true.