title: A Quantile Regression Approach to Estimating the Distribution of Anesthetic Procedure Time during Induction.
abstract: Although procedure time analyses are important for operating room management, it is not easy to extract useful information from clinical procedure time data. A novel approach was proposed to analyze procedure time during anesthetic induction. A two-step regression analysis was performed to explore influential factors of anesthetic induction time (AIT). Linear regression with stepwise model selection was used to select significant correlates of AIT and then quantile regression was employed to illustrate the dynamic relationships between AIT and selected variables at distinct quantiles. A total of 1,060 patients were analyzed. The first and second-year residents (R1-R2) required longer AIT than the third and fourth-year residents and attending anesthesiologists (p = 0.006). Factors prolonging AIT included American Society of Anesthesiologist physical status ≧ III, arterial, central venous and epidural catheterization, and use of bronchoscopy. Presence of surgeon before induction would decrease AIT (p < 0.001). Types of surgery also had significant influence on AIT. Quantile regression satisfactorily estimated extra time needed to complete induction for each influential factor at distinct quantiles. Our analysis on AIT demonstrated the benefit of quantile regression analysis to provide more comprehensive view of the relationships between procedure time and related factors. This novel two-step regression approach has potential applications to procedure time analysis in operating room management.
authors.affiliation: Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Anesthesiology, Hsinchu Mackay Memorial Hospital, Hsinchu, Taiwan.
authors.forename: Hsin-Lun
authors.initials: HL
authors.lastname: Wu
authors.affiliation: Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wen-Kuei
authors.initials: WK
authors.lastname: Chang
authors.affiliation: Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Ken-Hua
authors.initials: KH
authors.lastname: Hu
authors.affiliation: Pain and Anaesthesia Research Centre, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary College, University of London, London, EC1A 7BE, United Kingdom.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Langford
authors.affiliation: Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Mei-Yung
authors.initials: MY
authors.lastname: Tsou
authors.affiliation: Department of Anesthesiology, Taipei Veterans General Hospital and School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Kuang-Yi
authors.initials: KY
authors.lastname: Chang
mesh_terms: D000758:Anesthesia / Q000379:methods*; D000776:Anesthesiology / Q000193:education; D002404:Catheterization; D006801:Humans; D007396:Internship and Residency; D012044:Regression Analysis; D012189:Retrospective Studies; D013514:Surgical Procedures, Operative; D013997:Time Factors