We study the effects of waiting time and rescheduling on no-show behavior in an outpatient appointment system for both new and follow-up patients. Previous literature has primarily focused on new patients and investigated the role of waiting time on no-show probability. We offer a more nuanced understanding of this costly phenomenon. Using comprehensive clinical data, we demonstrate that waiting time has little effect on no-show behavior of follow-up patients. Instead, their no-show probability decreases significantly if their appointments were rescheduled at their own requests but increases significantly if they were rescheduled by the clinic. New patients, in contrast, are only concerned about waiting time and are insensitive to who initiates the rescheduling.

Our results provide useful implications for managing no-shows. First, clinics can strategically promote active rescheduling by follow-up patients to reduce no-shows; second, the slots freed up by such rescheduling can be offered to new patients, whose attendance would be boosted due to shorter waiting times. These policies can work collaboratively to reduce no-shows and increase throughput.