title: Assessing seasonality of travel distance to harm reduction service providers among persons who inject drugs.
abstract: BACKGROUND
  Prior research has examined access to syringe exchange program (SEP) services among persons who inject drugs (PWID), but no research has been conducted to evaluate variations in SEP access based on season. This is an important gap in the literature given that seasonal weather patterns and inclement weather may affect SEP service utilization. The purpose of this research is to examine differences in access to SEPs by season among PWID in the District of Columbia (DC).
  
  
  RESULTS
  A geometric point distance estimation technique was applied to records from a DC SEP that operated from 1996 to 2011. We calculated the walking distance (via sidewalks) from the centroid point of zip code of home residence to the exchange site where PWID presented for services. Analysis of variance (ANOVA) was used to examine differences in walking distance measures by season. Differences in mean walking distance measures were statistically significant between winter and spring with PWID traveling approximately 2.88 and 2.77 miles, respectively, to access the SEP during these seasons.
  
  
  CONCLUSIONS
  The results of this study suggest that seasonal differences in SEP accessibility may exist between winter and spring. PWID may benefit from harm reduction providers adapting their SEP operations to provide a greater diversity of exchange locations during seasons in which inclement weather may negatively influence engagement with SEPs. Increasing the number of exchange locations based on season may help resolve unmet needs among injectors.
authors.affiliation: Department of Prevention and Community Health, Milken Institute School of Public Health at The George Washington University, 950 New Hampshire Ave, Suite 300, Washington, DC, 20052, USA. seanallen@gwu.edu.
authors.forename: Sean T
authors.initials: ST
authors.lastname: Allen
authors.affiliation: Department of Prevention and Community Health, Milken Institute School of Public Health at The George Washington University, 950 New Hampshire Ave, Suite 300, Washington, DC, 20052, USA. msruiz@gwu.edu.
authors.forename: Monica S
authors.initials: MS
authors.lastname: Ruiz
authors.affiliation: Department of Prevention and Community Health, Milken Institute School of Public Health at The George Washington University, 950 New Hampshire Ave, Suite 300, Washington, DC, 20052, USA. aroess@gwu.edu.
authors.forename: Amira
authors.initials: A
authors.lastname: Roess
authors.affiliation: Department of Health Policy and Management, Jiann-Ping Hsu College of Public Health at Georgia Southern University, PO Box 8015, Statesboro, GA, 30460, USA. jajones@georgiasouthern.edu.
authors.forename: Jeff
authors.initials: J
authors.lastname: Jones
mesh_terms: D000704:Analysis of Variance; D015897:Comorbidity; D004219:District of Columbia / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control; D040261:Harm Reduction; D006297:Health Services Accessibility / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D018671:Needle-Exchange Programs / Q000706:statistics & numerical data*; D012621:Seasons; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*; D014195:Travel / Q000706:statistics & numerical data*; D016138:Walking; D014887:Weather