Current Procedural Terminology (CPT) codes, ICD-9-CM diagnostic and
procedure codes, and revenue center codes from physician claims files,
the hospital outpatient claims files, or the Medicare provider review
files. If a patient had at least one claim for chemotherapy within
6 months of surgery, she was coded as having received chemotherapy.
A second analysis was performed to determine the influence of the duration
of chemotherapy on outcomes for high-risk patients . To
exclude patients with recurrent and progressive disease, only high risk
patients who received