Personal factors as a cause of differences in prescribing by general practitioners.

The quantity and identity of drugs prescribed under the National Health Service vary widely between different towns (Martin, 1957; Benjamin and Ash, 1964). The reasons are not well understood, but differences of morbidity and mortality in the towns are not solely responsible (Lee, 1964). The differences in prescribing between towns remain relatively stable over months and years, so that the rank order of towns with different rates or different costs of prescribing is fairly stable (Ministry of Health Reports, 1963). In any town, there is considerable variation between individual doctors, and there is some evidence that the behaviour of particular doctors is also fairly stable over periods of time. Doctors differ not only in how much and how often they prescribe but also in what they prescribe (Weatherall, 1964), and it is desirable to understand the origin of such differences. A study of all the prescriptions issued in one month in each of three industrial towns has already been reported (Lee, 1964; Lee, Draper, and Weatherall, 1965). Most of the practitioners concerned in that study who had over 1,000 patients on their N.H.S. lists were interviewed about various aspects of their practice. The present paper describes these inter- views and their analysis in relation to the prescribing of the doctors interviewed.