How often do patients arrive late to appointments?

I don't know about late patients being the "bane" of anybody's existence, but they were sufficiently irritating that in 2013 doctors at the Johns Hopkins School of Medicine produced a study that attempted to improve patient punctuality. The study tracked the appointment and arrival times of 1,500 adult patient visits in an outpatient clinic in Maryland and found that 7.7 percent, or one-thirteenth, of those patients arrived at least one minute late. Almost no one was right on time — a huge 90.7 percent of patients arrived before their appointments. And they weren't just getting to the clinic with seconds to spare; on average, early arrivers got there 24.1 minutes beforehand. That's a greater miss than the average latecomer, who got there 20.5 minutes after the designated time.