Payesh
2009; 8: 327-333
Accepted for publication: 20 February 2007
[EPub a head of print-8 August 2009]

Objective(s): Providing a simulation model for understanding process and patient flow in outpatient clinics and estimating patients' waiting time.
Methods: This was a descriptive study. In this study outpatient clinics of general teaching hospitals in Tehran were grouped according to statistical distribution of patients' arrival time and a sample of each group was selected. Then the data of arrival time, service time and flow of patient at clinic for 357 patients were collected. At last a simulation model of outpatient clinics was provided and validated.
Results: Simulation model outputs showed that the mean patient waiting time for examination by novice resident was about 58 minutes, for experienced resident was about 52 minutes and for attend was about 53 minutes. Review of examination process with simulation model showed that about 42-62 percent of patients' waiting time for examination was before physician arrival at clinic. There were no statistical differences between new and follow-up patients' waiting time and waiting time for primary and complementary examination by residents and attend.
Conclusion: We found that the time gap between patient admission and arrival of physician was the most important factor in rising outpatient waiting time. Efforts to lessening this time will decrease total waiting time for examination about 60 percent.