Physician

Data on physician characteristics are obtained through physician self-report from the American Medical Association.

Active (or professionally active) physician

Currently engaged in patient care or other professional activity for a minimum of 20 hours per week. Other professional activity includes administration, medical teaching, research, and other activities such as employment with insurance carriers, pharmaceutical companies, corporations, voluntary organizations, and medical societies. Physicians who are retired, semiretired, working part time, or not practicing are classified as inactive and excluded. Also excluded are physicians with unknown addresses and physicians who did not provide information on type of practice or present employment (not classified).

Hospital-based physician

Employed under contract with hospitals to provide direct patient care, including physicians in residency training (including clinical fellows) and full-time members of the hospital staff.

Office-based physician

Engaged in seeing patients in solo practice, group practice, two-physician practice, or other patient care employment, or in providing inpatient services such as those offered by pathologists and radiologists.