Kemeny 2003.

Methods	Method: Retrospective case matched pair study in which older patients who were eligible for a trial were matched for disease stage and date of diagnosis with a younger patient also eligible for the trial and under the care of the same clinician. Setting: The 10 institutions in an American Cancer and Leukaemia Group which had the highest rate of recruitment to breast cancer trials c. 2003. RCT: Trials of treatment for breast cancer.
Data	Recruitment data: Clinician's decision to invite or not invite individual patients to participate in the trial. (Dis)incentive data: Age of patient.
Comparisons	Comparison of patients invited to participate with those not invited to participate according to age (dichotomised as under 65 versus 65 and over).
Outcomes	The decision of the clinician to invite or not invite individual patients to participate in the trial.
Notes	Age data reported for both patients for 67/77 (87%) matched pairs Confounding factors: Older patients had more comorbid conditions and were more likely to be widowed retired and to have functional limitations.