a Percentages are adjusted using sampling weights to produce national estimates.
b According to the Ninth Edition of the International Classification of Diseases (ICD-9): larynx, lung—161, 162; female breast—174; prostate = 185; colon, rectum—153, 154; lymphomas, leukemias—200-208; skin - 173; other = all other malignancies. Visit was considered cancer related if the principal diagnosis was coded as a malignant neoplasm (ICD-9 140 to 208).
c Oncology includes medical oncology and gynecological oncology; primary care includes family practice, internal medicine, and general practice; specialty surgery includes the following surgical specialties: colorectal, head and neck, neurosurgery, orthopedic, plastic, thoracic, cardiovascular, abdominal, and vascular. Other specialty includes hematology, gastroenterology, pulmonary disease, and others. Radiologists are not included in the NAMCS sample.
d Radiology clinics are not included in the NHAMCS sample.
SOURCE: USDHHS, 1999a, b.