Using computer simulation to reduce access time for outpatient departments.

AIM: To develop general applicable models for analysing the capacity needed in appointment-based hospital facilities.
METHOD: A fairly simple analytical queuing model was used to obtain rapid global insight into the capacity needed to meet the norm of seeing 95% of all new patients within 2 weeks. For more detailed analysis, a simulation model was developed that could handle daily variations in demand and capacity schedules. The capacity needed to eliminate backlogs and the capacity needed to keep access time within 2 weeks was calculated. Both models were applied to two outpatient departments (neurology and gynaecology) at the Academic Medical Center in Amsterdam, the Netherlands. Model results for neurology were implemented.
RESULTS: For neurology, to eliminate the 6-week backlog, 26 extra consultations per week were needed over 2 months. A permanent increase of 2-weekly consultations was required to keep access time within 2 weeks. Evaluation after implementation showed the improvements the model had predicted. The gynaecology department had sufficient capacity. With the simulation, it was calculated that the same service level could be achieved with 14% less capacity. Thus the models supported decisions made for departments with shortages of capacity as well as those for departments with adequate capacity.
CONCLUSION: The analytical model provided quick insight into the extra capacity needed for the neurology department. The added value of the simulation model was the possibility of taking into account variations in demand for different weekdays and a realistic schedule for doctors' consultations. General applicability of the models was shown by applying both models to the gynaecology department.