Patient selection
Women aged ≥65 years with stage I epithelial ovarian cancer diagnosed
as their first or only cancer between January 1, 1992 and December
31, 2009 were analyzed. Only women who underwent primary
cancer-directed surgery including oophorectomy were included .
Women who did not have full coverage of both Medicare parts A and
B or were enrolled in a non-Medicare health maintenance organization
from 12 months prior through 6months after cancer diagnosiswere excluded
because the billing claims for these patients were not submitted
toMedicare for reimbursement completely .