Analyzing Main and Interaction Effects of Length of Stay Determinants in Emergency Departments

Document Type : Original Article

Authors

1 Department of Business Administration, Yaşar University, İzmir, Turkey

2 Department of Emergency Medicine, Çiğli Regional Training Hospital, İzmir, Turkey

3 Department of General Surgery, Çiğli Regional Training Hospital, İzmir, Turkey

Abstract

Background
Measuring and understanding main determinants of length of stay (LOS) in emergency departments (EDs) is critical from an operations perspective, since LOS is one of the main performance indicators of ED operations. Therefore, this study analyzes both the main and interaction effects of four widely-used independent determinants of ED-LOS.
 
Methods
The analysis was conducted using secondary data from an ED of a large urban hospital in Izmir, Turkey. Between-subject factorial analysis of variance (ANOVA) was used to test the main and interaction effects of the corresponding factors. P values  
Results
While the main effect of gender was insignificant, age, mode of arrival, and clinical acuity had significant effects, whereby ED-LOS was significantly higher for the elderly, those arriving by ambulance, and clinically-categorized high-acuity patients. Additionally, there was an interaction between the age and clinical acuity in that, while ED-LOS increased with age for high acuity patients, the opposite trend occurred for low acuity patients. When ED-LOS was modeled using gender, age, and mode of arrival, there was a significant interaction between age and mode of arrival. However, this interacton was not significant when the model included age, mode of arrival, and clinical acuity.
 
Conclusion
Significant interactions exist between commonly used ED-LOS determinants. Therefore, interaction effects should be considered in analyzing and modelling ED-LOS.

Highlights

Supplementary File 1 (Download)

Supplementary File 2 (Download)

Keywords

Main Subjects


  1. Hu YH, Tai CT, Chen SC, Lee HW, Sung SF. Predicting return visits to the emergency department for pediatric patients: applying supervised learning techniques to the Taiwan National Health Insurance Research Database. Comput Methods Programs Biomed. 2017;144:105-112. doi:10.1016/j.cmpb.2017.03.022
  2. Wolfe A. Institute of Medicine Report: Crossing the Quality Chasm: A New Health Care System for the 21st Century. Policy Polit Nurs Pract. 2001;2(3):233-235. doi:10.1177/152715440100200312.
  3. Banerjea K, Carter AO. Waiting and interaction times for patients in a developing country accident and emergency department. Emerg Med J. 2006;23(4):286-290. doi:10.1136/emj.2005.024695
  4. Forster AJ, Stiell I, Wells G, Lee AJ, van Walraven C. The effect of hospital occupancy on emergency department length of stay and patient disposition. Acad Emerg Med. 2003;10(2):127-133. doi:10.1111/j.1553-2712.2003.tb00029.x
  5. Nippak PM, Isaac WW, Ikeda-Douglas CJ, Marion AM, VandenBroek M. Is there a relation between emergency department and inpatient lengths of stay? Can J Rural Med. 2014;19(1):12-20.
  6. Rashid A, Brooks TR, Bessman E, Mears SC. Factors associated with emergency department length of stay for patients with hip fracture. Geriatr Orthop Surg Rehabil. 2013;4(3):78-83. doi:10.1177/2151458513502038
  7. Serinken M, Karcioglu O, Turkcuer I, Ozkan HI, Keysan MK, Bukiran A. Analysis of clinical and demographic characteristics of patients presenting with renal colic in the emergency department. BMC Res Notes. 2008;1:79. doi:10.1186/1756-0500-1-79
  8. Bickell NA, Hwang U, Anderson RM, Rojas M, Barsky CL. What affects time to care in emergency room appendicitis patients? Med Care. 2008;46(4):417-422. doi:10.1097/MLR.0b013e31815c1e66
  9. Capuano F, Lot AS, Sagnes-Raffy C, et al. Factors associated with the length of stay of patients discharged from emergency department in France. Eur J Emerg Med. 2015;22(2):92-98. doi:10.1097/mej.0000000000000109
  10. Gardner RL, Sarkar U, Maselli JH, Gonzales R. Factors associated with longer ED lengths of stay. Am J Emerg Med. 2007;25(6):643-650. doi:10.1016/j.ajem.2006.11.037
  11. Goodacre S, Webster A. Who waits longest in the emergency department and who leaves without being seen? Emerg Med J. 2005;22(2):93-96. doi:10.1136/emj.2003.007690
  12. Sarıyer G, Ataman MG, Kızıloğlu İ. Factors affecting length of stay in the emergency department: a research from an operational viewpoınt. Int J Healthc Manag. 2018:1-10. doi:10.1080/20479700.2018.1489992
  13. Weiss AP, Chang G, Rauch SL, et al. Patient- and practice-related determinants of emergency department length of stay for patients with psychiatric illness. Ann Emerg Med. 2012;60(2):162-171.e165. doi:10.1016/j.annemergmed.2012.01.037
  14. Wu BU, Banks PA, Conwell DL. Disparities in emergency department wait times for acute gastrointestinal illnesses: results from the National Hospital Ambulatory Medical Care Survey, 1997-2006. Am J Gastroenterol. 2009;104(7):1668-1673. doi:10.1038/ajg.2009.189
  15. Baum SA, Rubenstein LZ. Old people in the emergency room: age-related differences in emergency department use and care. J Am Geriatr Soc. 1987;35(5):398-404. doi:10.1111/j.1532-5415.1987.tb04660.x
  16. Biber R, Bail HJ, Sieber C, Weis P, Christ M, Singler K. Correlation between age, emergency department length of stay and hospital admission rate in emergency department patients aged >/=70 years. Gerontology. 2013;59(1):17-22. doi:10.1159/000342202
  17. Downing A, Wilson RC, Cooke MW. Which patients spend more than 4 hours in the Accident and Emergency department? J Public Health (Oxf). 2004;26(2):172-176. doi:10.1093/pubmed/fdh141
  18. Elkum N, Fahim M, Shoukri M, Al-Madouj A. Which patients wait longer to be seen and when? a waiting time study in the emergency department. East Mediterr Health J. 2009;15(2):416-424.
  19. Hamdy RC, Forrest LJ, Moore SW, Cancellaro L. Use of emergency departments by the elderly in rural areas. South Med J. 1997;90(6):616-620. doi:10.1097/00007611-199706000-00007
  20. Kawano T, Nishiyama K, Anan H, Tujimura Y. Direct relationship between aging and overcrowding in the ED, and a calculation formula for demand projection: a cross-sectional study. Emerg Med J. 2014;31(1):19-23. doi:10.1136/emermed-2012-202050
  21. Lowthian JA, Curtis AJ, Jolley DJ, Stoelwinder JU, McNeil JJ, Cameron PA. Demand at the emergency department front door: 10-year trends in presentations. Med J Aust. 2012;196:128-132. doi:10.5694/mja11.10955
  22. Casalino E, Wargon M, Peroziello A, et al. Predictive factors for longer length of stay in an emergency department: a prospective multicentre study evaluating the impact of age, patient's clinical acuity and complexity, and care pathways. Emerg Med J. 2014;31(5):361-368. doi:10.1136/emermed-2012-202155
  23. Karaca Z, Wong HS, Mutter RL. Duration of patients' visits to the hospital emergency department. BMC Emerg Med. 2012;12:15. doi:10.1186/1471-227x-12-15
  24. Pines JM, Russell Localio A, Hollander JE. Racial disparities in emergency department length of stay for admitted patients in the United States. Acad Emerg Med. 2009;16(5):403-410. doi:10.1111/j.1553-2712.2009.00381.x
  25. Stephens RJ, White SE, Cudnik M, Patterson ES. Factors associated with longer length of stay for mental health emergency department patients. J Emerg Med. 2014;47(4):412-419. doi:10.1016/j.jemermed.2014.04.040
  26. Mahmoud I, Hou XY, Chu K, Clark M. Language affects length of stay in emergency departments in Queensland public hospitals. World J Emerg Med. 2013;4(1):5-9. doi:10.5847/wjem.j.1920-8642.2013.01.001
  27. Wallbrecht J, Hodes-Villamar L, Weiss SJ, Ernst AA. No difference in emergency department length of stay for patients with limited proficiency in English. South Med J. 2014;107(1):1-5. doi:10.1097/smj.0000000000000037
  28. Azzopardi M, Cauchi M, Cutajar K, Ellul R, Mallia-Azzopardi C, Grech V. A time and motion study of patients presenting at the accident and emergency department at Mater Dei Hospital. BMC Res Notes. 2011;4:421. doi:10.1186/1756-0500-4-421
  29. Rose L, Gray S, Burns K, et al. Emergency department length of stay for patients requiring mechanical ventilation: a prospective observational study. Scand J Trauma Resusc Emerg Med. 2012;20:30. doi:10.1186/1757-7241-20-30
  30. Ay D, Akkas M, Sivri B. Patient population and factors determining length of stay in adult ED of a Turkish University Medical Center. Am J Emerg Med. 2010;28(3):325-330. doi:10.1016/j.ajem.2008.12.011
  31. Schull MJ, Kiss A, Szalai JP. The effect of low-complexity patients on emergency department waiting times. Ann Emerg Med. 2007;49(3):257-264, 264.e251. doi:10.1016/j.annemergmed.2006.06.027
  32. Brouns SH, Stassen PM, Lambooij SL, Dieleman J, Vanderfeesten IT, Haak HR. Organisational factors induce prolonged emergency department length of stay in elderly patients--a retrospective cohort study. PLoS One. 2015;10(8):e0135066. doi:10.1371/journal.pone.0135066
  33. Davis B, Sullivan S, Levine A, Dallara J. Factors affecting ED length-of-stay in surgical critical care patients. Am J Emerg Med. 1995;13(5):495-500. doi:10.1016/0735-6757(95)90155-8
  34. Kocher KE, Meurer WJ, Desmond JS, Nallamothu BK. Effect of testing and treatment on emergency department length of stay using a national database. Acad Emerg Med. 2012;19(5):525-534. doi:10.1111/j.1553-2712.2012.01353.x
  35. Li L, Georgiou A, Vecellio E, et al. The effect of laboratory testing on emergency department length of stay: a multihospital longitudinal study applying a cross-classified random-effect modeling approach. Acad Emerg Med. 2015;22(1):38-46. doi:10.1111/acem.12565
  36. Yoon P, Steiner I, Reinhardt G. Analysis of factors influencing length of stay in the emergency department. CJEM. 2003;5(3):155-161. doi:10.1017/s1481803500006539
  37. Derose SF, Gabayan GZ, Chiu VY, Yiu SC, Sun BC. Emergency department crowding predicts admission length-of-stay but not mortality in a large health system. Med Care. 2014;52(7):602-611. doi:10.1097/mlr.0000000000000141
  38. McCarthy ML, Zeger SL, Ding R, et al. Crowding delays treatment and lengthens emergency department length of stay, even among high-acuity patients. Ann Emerg Med. 2009;54(4):492-503.e494. doi:10.1016/j.annemergmed.2009.03.006
  39. Wiler JL, Handel DA, Ginde AA, et al. Predictors of patient length of stay in 9 emergency departments. Am J Emerg Med. 2012;30(9):1860-1864. doi:10.1016/j.ajem.2012.03.028
  40. Sun BC, Hsia RY, Weiss RE, et al. Effect of emergency department crowding on outcomes of admitted patients. Ann Emerg Med. 2013;61(6):605-611.e606. doi:10.1016/j.annemergmed.2012.10.026
  41. Gilboy N, Tanabe P, Travers D, Rosenau AM. Emergency Severity Index (ESI): A triage tool for emergency department care, version 4. Implementation handbook 2012 edition. AHRQ Publication; 2011.
  42. Bower KM. Analysis of Variance (ANOVA) using MINITAB. Scientific Computing & Instrumentation. 2000;17:64-65.
  43. Sarıyer G, Öcal Taşar C, Ersoy Cepe G. Use of data mining techniques to classify length of stay of emergency department patients. Bio-Algorithms and Med-Systems. 2019;15(1). doi:10.1515/bams-2018-0044
  44. Gill D, Galvin S, Ponsford M, et al. Laboratory sample turnaround times: do they cause delays in the ED? J Eval Clin Pract. 2012;18(1):121-127. doi:10.1111/j.1365-2753.2010.01545.x
Volume 9, Issue 5
May 2020
Pages 198-205
  • Receive Date: 17 January 2019
  • Revise Date: 28 October 2019
  • Accept Date: 30 October 2019
  • First Publish Date: 01 May 2020