Looks like though Polyclinic is more overloaded with patients than hospital, they are better managed as far as consultation waiting time is concerned.
Polyclinic - without appointment, the waiting time is about 1 to 3 hours. With appointment, it is around 20 to 45 minutes.
Hospital (eg. CGH, SNEC) - even with appointment, the waiting time is 1 to 2 hours. Those without appointment normally goes under 'emergency' cases, which I understand has l-o-n-g waiting time too, besides footing a heavy bill.
So if it is not a matter of life and death, might as well consult a doctor in the polyclinic if one does not have prior appointment, since the waiting time in hospital emergency ward is equally daunting.
As for prior medical appointment in hospital, it is time they do a review of their time management since it is very unproductive for patients to be kept waiting for hours well past their appointment time.
If the govt is serious about improving productivity, Ministry of Health should tell all the hospitals to stop wasting so many man-hours of patients' time - waiting and waiting to see their doctors. It defeats the whole purpose of giving the patient an appointment time if it is so badly managed.