How much of a general practitioner's prescribing is outside his/her control?

OBJECTIVE: To analyse and quantify that portion of one General Practioner's prescribing that is outside his/her control. DESIGN: Detailed analysis of one General Practioner's General Medical Services prescribing over a three month period during 1996. SETTING: A Group Practice in Sligo, Ireland. MAIN OUTCOME MEASURES: The number and cost of items outside the General Practitioner's control expressed as a percentage of his total General Medical Services prescribing. The source of these items, and whether they are newly prescribed items or not. RESULTS: 12.8% numerically and 23.8%, costwise, of items prescribed by one GMS General Practitioner were found to be outside his control. Of these items, psychiatric outpatient consultations and medical in-patient discharges account for 22.8% and 18.4% numerically, respectively, and 25.7% and 22.6% costwise, respectively of the total numbers of items and costs outside his control. CONCLUSIONS: A relatively small proportion of items of a General Practitioners prescribing accounting for a disproportionately large amount of the costs are outside his control.