title: Tracking Hookah Bars in New York: Utilizing Yelp as a Powerful Public Health Tool.
abstract: BACKGROUND
  While cigarette use has seen a steady decline in recent years, hookah (water pipe) use has rapidly increased in popularity. While anecdotal reports have noted a rise in hookah bars, methodological difficulties have prevented researchers from drawing definitive conclusions about the number of hookah bars in any given location. There is no publicly available database that has been shown to reliably provide this information. It is now possible to analyze Internet trends as a measure of population behavior and health-related phenomena.
  
  
  OBJECTIVE
  The objective of the study was to investigate whether Yelp can be used to accurately identify the number of hookah bars in New York State, assess the distribution and characteristics of hookah bars, and monitor temporal trends in their presence.
  
  
  METHODS
  Data were obtained from Yelp that captures a variety of parameters for every business listed in their database as of October 28, 2014, that was tagged as a "hookah bar" and operating in New York State. Two algebraic models were created: one estimated the date of opening of a hookah bar based on the first Yelp review received and the other estimated whether the bar was open or closed based on the date of the most recent Yelp review. These findings were then compared with empirical data obtained by Internet searches.
  
  
  RESULTS
  From 2014 onward, the date of the first Yelp review predicts the opening date of new hookah bars to within 1 month. Yelp data allow the estimate of such venues and demonstrate that new bars are not randomly distributed, but instead are clustered near colleges and in specific racial/ethnic neighborhoods. New York has seen substantially more new hookah bars in 2012-2014 compared with the number that existed prior to 2009.
  
  
  CONCLUSIONS
  Yelp is a powerful public health tool that allows for the investigation of various trends and characteristics of hookah bars. New York is experiencing tremendous growth in hookah bars, a worrying phenomenon that necessitates further investigation.
authors.affiliation: Department of Pediatrics New York University School of Medicine New York, NY United States.
authors.forename: Philip B
authors.identifier: 0000-0002-7873-1896
authors.initials: PB
authors.lastname: Cawkwell
authors.affiliation: Department of PediatricsNew York University School of MedicineNew York, NYUnited States; Brooklyn CollegeBrooklyn, NYUnited States.
authors.forename: Lily
authors.identifier: 0000-0001-9716-1983
authors.initials: L
authors.lastname: Lee
authors.affiliation: Department of PediatricsNew York University School of MedicineNew York, NYUnited States; College of Global Public HealthNew York UniversityNew York, NYUnited States; Department of Environmental HealthNew York University School of MedicineNew York, NYUnited States; NYU/Abu Dhabi Public Health Research CenterAbu DhabiUnited Arab Emirates.
authors.forename: Michael
authors.identifier: 0000-0002-3357-6351
authors.initials: M
authors.lastname: Weitzman
authors.affiliation: College of Global Public HealthNew York UniversityNew York, NYUnited States; NYU/Abu Dhabi Public Health Research CenterAbu DhabiUnited Arab Emirates; Department of Population HealthNew York University School of MedicineNew York, NYUnited States; Department of MedicineVA New York Harbor Healthcare SystemNew York, NYUnited States.
authors.forename: Scott E
authors.identifier: 0000-0003-1752-7303
authors.initials: SE
authors.lastname: Sherman
keywords: Internet; Yelp; hookah; hookah bar; public health