title: Bed Capacity Planning Using Stochastic Simulation Approach in Cardiac-surgery Department of Teaching Hospitals, Tehran, Iran.
abstract: BACKGROUND
  To determine the hospital required beds using stochastic simulation approach in cardiac surgery departments.
  
  
  METHODS
  This study was performed from Mar 2011 to Jul 2012 in three phases: First, collection data from 649 patients in cardiac surgery departments of two large teaching hospitals (in Tehran, Iran). Second, statistical analysis and formulate a multivariate linier regression model to determine factors that affect patient's length of stay. Third, develop a stochastic simulation system (from admission to discharge) based on key parameters to estimate required bed capacity.
  
  
  RESULTS
  Current cardiac surgery department with 33 beds can only admit patients in 90.7% of days. (4535 d) and will be required to over the 33 beds only in 9.3% of days (efficient cut off point). According to simulation method, studied cardiac surgery department will requires 41-52 beds for admission of all patients in the 12 next years. Finally, one-day reduction of length of stay lead to decrease need for two hospital beds annually.
  
  
  CONCLUSIONS
  Variation of length of stay and its affecting factors can affect required beds. Statistic and stochastic simulation model are applied and useful methods to estimate and manage hospital beds based on key hospital parameters.
authors.affiliation: Dept. of Health Services Management, School of Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran; Dept. of Health Economics & Management, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Amin
authors.initials: A
authors.lastname: Torabipour
authors.affiliation: Dept. of Epidemiology & Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hojjat
authors.initials: H
authors.lastname: Zeraati
authors.affiliation: Dept. of Health Economics & Management, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Arab
authors.affiliation: Dept. of Health Economics & Management, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Arash
authors.initials: A
authors.lastname: Rashidian
authors.affiliation: Dept. of Health Economics & Management, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Akbari Sari
authors.affiliation: Dept. of Cardiac Surgery, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mahmuod Reza
authors.initials: MR
authors.lastname: Sarzaiem
keywords: Cardiac surgery department; Hospital beds; Hospital stay; Stochastic simulation