Waiting for the doctor.

The best time interval between appointments in general practice surgeries where patients were allocated specific times to see their doctor was studied. A mathematical model which simulates the pattern of the arrival of patients and consultations at the surgery, and which can be run rapidly on computer, was constructed. The model can be applied to any general practitioner's surgery that operates an appointments system. The only inputs necessary are observations of the arrival times and consultation times of all patients at 10 of the doctor's surgeries. The scope of the reduction in waiting times that was attained in one practice is discussed.