title: Association of doxycycline prescriptions and tick-related emergency department visits in North Carolina.
abstract: OBJECTIVE
  To compare the seasonal frequency of doxycycline prescriptions with tick-related emergency department (ED) visits in North Carolina, and to determine if doxycycline prescriptions are associated in time with an increase in the number of ED visits for a tick-related patient complaint or a subsequent diagnosis of a tick-borne infection.
  
  
  METHODS
  Aggregate monthly counts of total dispensed doxycycline prescriptions for each North Carolina Piedmont Metropolitan Statistical Area (MSA) were compared with the proportions of tick-related ED visits from August 2007 through July 2009.
  
  
  RESULTS
  Epidemic curves of tick-related ED visits for each of the 6 MSAs were characterized by increased frequency in the spring and summer months followed by a decline in the fall. However, the pattern of doxycycline prescriptions varied by MSA. Doxycycline prescriptions in Durham-Chapel Hill and Raleigh-Cary MSAs increased in the spring and summer, while for the 4 other Piedmont MSAs there was no consistent or pronounced spring-summer increase.
  
  
  CONCLUSIONS
  Doxycycline prescription use did not always correlate well with suspected tick activity in North Carolina. Therefore, doxycycline prescription use cannot necessarily be used as a surrogate measure of tick activity for infectious disease surveillance until the reasons for this variability are better understood.
authors: University of North Carolina at Chapel Hill, Department of Emergency Medicine, Chapel Hill, NC 27599-7594, USA. srhea@email.unc.edu
authors: Sarah
authors: S
authors: Rhea
authors: Seth
authors: S
authors: Glickman
authors: Anna
authors: A
authors: Waller
authors: Carl
authors: C
authors: Williams
authors: Larry
authors: L
authors: Glickman
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D004318:Doxycycline / Q000008:administration & dosage*; D011307:Drug Prescriptions / Q000706:statistics & numerical data*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D058872:Epidemics / Q000706:statistics & numerical data; D005500:Follow-Up Studies; D006801:Humans; D009657:North Carolina / Q000453:epidemiology; D010349:Patient Compliance / Q000706:statistics & numerical data; D055553:Prescription Drugs / Q000600:supply & distribution*; D012189:Retrospective Studies; D012621:Seasons; D017282:Tick-Borne Diseases / Q000188:drug therapy* / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D055553:Prescription Drugs; D004318:Doxycycline