Although i do think that using both ordinal and interval scale in predicting mortality will produce better results, is it possible to use just one scale if so what are the implications?
It is possible to use either an ordinal or an interval scale to predict patient’s prognosis. For example, patients’ mortality can be regressed on an ordinal scale by introducing several dummy variables, one for each value of the ordinal scale. There is no a priori reason to expect that either the ordinal or the interval scale will be more accurate but the regression on the interval scale will require fewer data items as there are fewer parameters to estimate. As the number of levels of the ordinal scale increases more parameters need to be estimated and therefore more data is needed. This question was asked on 2/25/2008 1:12:07 AM and answered on 2/25/2008 7:02:49 AM.
