title: "Black cloud" vs. "white cloud" physicians - Myth or reality in apheresis medicine?
abstract: BACKGROUND
  Many practitioners believe in the phenomenon of either being labeled a "black cloud" or "white cloud" while on-call. A "white-cloud" physician is one who usually gets fewer cases. A "black-cloud" is one who often has more cases. It is unclear if the designation is only superstitious or if there is some merit. Our aim is to objectively assess this phenomenon in apheresis medicine at our center.
  
  
  METHODS
  A one-year prospective study from 12/2014 to 11/2015 was designed to evaluate the number of times apheresis physicians and nurses were involved with emergent apheresis procedures between the hours from 10 PM and 7 AM. Other parameters collected include the names of the physician, apheresis nurse, type of emergent apheresis procedure, day of the week, and season of the year.
  
  
  RESULTS
  During the study period, 32 emergent procedures (or "black-cloud" events) occurred. The median time between two consecutive events was 8 days (range: 1-34 days). We found no statistically significant association between the "black-cloud" events and attending physicians, nurses, day of the week, or season of the year by Chi-square and Fisher's analyses. However, exploratory analysis using association rule demonstrated that "black-cloud" events were more likely to happen on Thursday (2.19 times), with attending physician 2 (1.18 times), and during winter (1.15 times).
  
  
  CONCLUSIONS
  The results of this pilot study may support the common perception that some physicians or nurses are either "black cloud" or "white cloud". A larger, multi-center study population is needed to validate the results of this pilot study.
authors.affiliation: Department of Pathology, Division of Laboratory Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Huy P
authors.initials: HP
authors.lastname: Pham
authors.affiliation: Department of Acute, Chronic, and Continuing Care, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Dheeraj
authors.initials: D
authors.lastname: Raju
authors.affiliation: Center for Family Life at Sunset Park, SCO Family of Services, Brooklyn, New York.
authors.forename: Ning
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Department of Pathology, Division of Laboratory Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
authors.forename: Lance A
authors.initials: LA
authors.lastname: Williams
mesh_terms: D001781:Blood Component Removal / Q000706:statistics & numerical data*; D004632:Emergency Medical Services / Q000706:statistics & numerical data; D006801:Humans; D008505:Medical Staff, Hospital / Q000706:statistics & numerical data; D010820:Physicians / Q000706:statistics & numerical data*; D010865:Pilot Projects; D011446:Prospective Studies; D016526:Workload / Q000706:statistics & numerical data*
keywords: apheresis; black cloud; perceived workload; psychology; white cloud