title: Investigating the relationship between weather and violence in Baltimore, Maryland, USA.
abstract: BACKGROUND
  It is a common refrain at major urban trauma centers that caseloads increase in the heat of the summer. Several previous studies supported this assertion, finding trauma admissions and crime to correlate positively with temperature. We examined links between weather and violence in Baltimore, MD, through trauma presentation to Johns Hopkins Hospital and crime reports filed with the Baltimore Police Department.
  
  
  METHODS
  Crime data were obtained from the Baltimore City Police Department from January 1, 2008 to March 31, 2013. Trauma data were obtained from a prospectively collected registry of all trauma patients presenting to Johns Hopkins Hospital from January 1, 2007 to March 31, 2013. Weather data were obtained from the National Climatic Data Center. Correlation coefficients were calculated and negative binomial regression was used to elucidate the independent associations of weather and temporal variables with the trauma and crime data.
  
  
  RESULTS
  When adjusting for temporal and meteorological factors, maximum daily temperature was positively associated with total trauma, intentional injury, and gunshot wounds presenting to Johns Hopkins Hospital along with total crime, violent crime, and homicides in Baltimore City. Associations of average wind speed, daily precipitation, and daily snowfall with trauma and crime were far weaker and, when significant, nearly universally negative.
  
  
  CONCLUSIONS
  Maximum daily temperature is the most important weather factor associated with violence and trauma in our study period and location. Our findings suggest potential implications for hospital staffing to be explored in future studies.
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Michel
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Han
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Shalini
authors.initials: S
authors.lastname: Selvarajah
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Joseph K
authors.initials: JK
authors.lastname: Canner
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Murrill
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Albert
authors.initials: A
authors.lastname: Chi
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: David T
authors.initials: DT
authors.lastname: Efron
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: eschnei1@jhmi.edu.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Schneider
mesh_terms: D015142:Baltimore / Q000453:epidemiology; D003415:Crime / Q000523:psychology*; D005260:Female; D006708:Homicide / Q000523:psychology* / Q000706:statistics & numerical data; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008962:Models, Theoretical; D011446:Prospective Studies; D018570:Risk Assessment; D012621:Seasons; D013696:Temperature; D014193:Trauma Centers / Q000706:statistics & numerical data; D014754:Violence / Q000523:psychology* / Q000706:statistics & numerical data; D014887:Weather; D014947:Wounds and Injuries / Q000453:epidemiology / Q000209:etiology / Q000523:psychology*
keywords: Baltimore; Temperature; Trauma; Violence; Violent crime; Weather