Outpatient Appointment Scheduling: Back to
Basics
Chew San Lee, Natalie
Abstract
This paper focuses on the performance measures of outpatient appointment scheduling
models. We hypothesize that a performance measure that incorporates risk and uncertainty
will be more effective than the commonly used weighted average performance measure
(WAPM) at producing a patient-preferred appointment rule. Patients’ waiting time
preferences were determined through a simple survey and which were indeed shown to be
incongruent with the results obtained from the use of the WAPM. We propose a new
performance measure, the Threshold Observing Punctuality (TOP) index, which through the
use of the Conditional Value-at-Risk concept, considers patients’ risk preferences. An
improvement to the WAPM, the TOP index is shown to be effective in fulfilling the aforedetermined waiting time preferences. Consequently, a distinct advantage of the TOP index
is its ability to produce a fairer appointment rule, where the longest expected waiting time is
consistently less than that derived from using the WAPM. By aligning performance measures
to the preferences of patients, meaningful application and positive clinical impact can be
achieved. Future studies may include an exploration of decision-making in the context of
time, which can contribute to a clearer elucidation of patient’s waiting time preferences, and
hence allow for greater value add to patients in the near future.