title: Comparison of Direct and Indirect Measures of E-cigarette Risk Perceptions.
abstract: OBJECTIVE
  Risk perception measures of tobacco products relative to cigarettes are commonly used and important to tobacco research given that they may be associated with and predict tobacco use. However, results may differ based on measures used. This study compares direct and indirect approaches to measuring e-cigarette/cigarette risk perceptions.
  
  
  METHODS
  We compared the responses of 519 current smokers on a nationally representative 2014 survey that gauged perceptions of e-cigarettes' harm relative to cigarettes in two ways: 1) a single-item direct measure of comparative harm and a two-itemindirectmeasure (which measured perceived levels of harm from e-cigarettes and cigarettes independently in two parallel questions).
  
  
  RESULTS
  We found that 60% of smokers rated e-cigarettes "less harmful" than cigarettes when using a direct comparative risk measure versus 73% when using an indirect measure. Agreement between measure types was fair (Cohen's Kappa=0.45) and was lower for males, Blacks, older and less educated smokers.
  
  
  CONCLUSIONS
  E-cigarettes were more likely to be rated by smokers as less harmful than cigarettes when using indirect versus direct measures. Additional methodology research into this area is warranted given the importance of risk perceptions to tobacco control interventions, communications, policy-making and regulation.
authors: Assistant Professor, Rutgers School of Public Health, Center for Tobacco Studies, New Brunswick, NJ.
authors: Olivia A
authors: OA
authors: Wackowski
authors: Rutgers School of Public Health, Center for Tobacco Studies, New Brunswick, NJ.
authors: Michelle T
authors: MT
authors: Bover Manderski
authors: Professor, Rutgers School of Public Health, Center for Tobacco Studies, New Brunswick, NJ.
authors: Cristine D
authors: CD
authors: Delnevo
keywords: e-cigarettes; risk perceptions; survey methods