The effect of mixed distributions on the methods of survival analysis.
A study of the effectiveness of preoperative radiation as an adjuvant for surgery for patients with invasive bladder carcinoma revealed a subpopulation of patients having advanced disease who could not benefit from radiation treatment. The effect of such a group of patients on the efficiency of 2 common nonparametric tests is investigated here. Both Gehan's tests and Greenwood's tests were shown to have a very low efficiency when compared with a parametric test when this group of patients is present.
D006801:Humans; D008954:Models, Biological; D013223:Statistics as Topic; D001749:Urinary Bladder Neoplasms / Q000401:mortality* / Q000532:radiotherapy / Q000601:surgery