Age as a criterion for eligibility in a lung cancer clinical trial

The results of a clinical trial can be generalized only if the study sample is representative of the population with the disease entity under study. A prerequisite for patient participation in a clinical trial is that all the eligibility criteria be met. In many cooperative group trials, it is common practice to use age as a criterion for eligibility on the premise that advanced age is an unfavorable prognostic factor. In this paper, we evaluate the bias introduced in a sample when this practice was followed in a lung cancer protocol. Of 653 lung cancer cases reviewed, 77 met the eligibility criteria; an additional 23 patients were ineligible for the trial solely on the basis of age. There was no significant difference in survival between these two groups of patients. This indicates that age is not an unfavorable prognostic factor for patients with lung cancer and should not be used as a criterion for eligibility in a clinical trial.