Changes resulting from increasing appointment length: practical and theoretical issues.

The experience of one urban teaching practice in changing its appointment length from 7.5 to 10.0 minutes is described. Observed benefits to patients attending routine surgeries included an increased consultation time (mean 8.6 minutes before, 9.1 minutes after) and reduced waiting time (mean 19.1 minutes compared with 14.6 minutes). Overall, workload was unchanged but improving the 'fit' between supply and demand was associated with loss of flexibility--a greater number of extra patients required to be seen, apparently because fewer appointments were available at the start of each day. Waiting and consultation times in teaching surgeries and trainee surgeries (booked throughout at 10.0 minute intervals) were unchanged in response to the new arrangements. The changes introduced were well received by medical and reception staff although their response was not formally measured. Planning the organization of an appointment system requires several distinct decisions to be made. The preferred or actual average length of consultations has to be decided and booking arrangements designed to enable this to take place without the doctors persistently running over time. The number of appointments per week required to meet anticipated demand has to be calculated on the basis of list size and expected annual consultation rate. However, an exact fit between supply and demand will lead to congestion of the system and it appears that flexibility in the form of an overprovision of appointments to projected demand of about 120% should be built in. Sufficient vacant slots must be provided at the start of each day to allow sufficient flexibility to avoid excessive numbers of patients having to be accommodated.(ABSTRACT TRUNCATED AT 250 WORDS)