title: Measuring statewide merchant compliance with tobacco minimum age laws: the Massachusetts experience.
abstract: OBJECTIVE
  This study evaluated merchant compliance with laws prohibiting the sale of tobacco to minors in Massachusetts.
  
  
  METHODS
  Stratified cluster sampling was used to select outlets from which youths aged 13 to 17 years attempted to purchase tobacco.
  
  
  RESULTS
  Illegal sales were more common when the youth purchasing the tobacco was older, when the clerk was male, and when tobacco was obtained from a self-service display or unlocked vending machine. Failure to request proof of age was the strongest predictor of illegal sales.
  
  
  CONCLUSIONS
  Measured compliance rates are strongly influenced by the age of the youths used to purchase tobacco.
authors.affiliation: Department of Family Medicine and Community Health, University of Massachusetts Medical Center, Worcester, MA 01655, USA. difranzj@ummhc.org
authors.forename: J R
authors.initials: JR
authors.lastname: DiFranza
authors.forename: C C
authors.initials: CC
authors.lastname: Celebucki
authors.forename: P D
authors.initials: PD
authors.lastname: Mowery
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D000367:Age Factors; D016009:Chi-Square Distribution; D016000:Cluster Analysis; D003132:Commerce / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data; D016015:Logistic Models; D008389:Marketing of Health Services / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data; D008404:Massachusetts; D011237:Predictive Value of Tests; D012737:Sex Factors; D012907:Smoking / Q000331:legislation & jurisprudence; D000074606:Smoking Prevention