Pitfalls in the evaluation of prognostic factors.
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D006801:Humans; D007938:Leukemia / Q000401:mortality* / Q000628:therapy; D007945:Leukemia, Lymphoid / Q000401:mortality* / Q000628:therapy; D011379:Prognosis; D012107:Research Design