title: Tobacco use and quit behaviour assessment in the Global Adult Tobacco Survey (GATS): invalid responses and implications.
abstract: BACKGROUND
  Tobacco use and quit attempts are two key indicators of the Global Adult Tobacco Survey (GATS) that assess quit attempts among current as well as former tobacco users. The relevant data have inherent policy implications for tobacco cessation programme evaluation. This study aimed to review the concepts of quit attempt assessment and quantifying invalid responses considering GATS-India data.
  
  
  METHODS
  GATS assessment of tobacco use and quit attempts were examined in the current literature. Two categories of invalid responses were identified by stratified analysis of the duration of last quit attempt among current users and duration of abstinence among former users. Category A included absolute invalid responses when time- frame of assessment of current tobacco use and less than former tobacco use were violated. Category B included responses that violated the unit of measurement of time.
  
  
  RESULTS
  Current daily use, current less than daily use and former use in GATS were imprecisely defined with overlapping of time-frame of assessment. Overall responses of 3,102 current smokers, 4,036 current smokeless users, 1,904 former smokers and 1,343 former smokeless users were analyzed to quantify invalid responses. Analysis indicated overall 21.2% (category A: 7.32%; category B: 17.7%) and 22.7% (category A: 8.05%; category B: 18.1%) invalid responses among current smokers and smokeless users respectively regarding their duration of last quit attempt. Similarly overall 6.62% (category A: 4.7%; category B: 2.3%) and 10.6% (category A: 8.6%; category B: 3.5%) invalid responses were identified among former smokers and smokeless users respectively regarding their duration of abstinence.
  
  
  CONCLUSIONS
  High invalid responses for a single assessment are due to the imprecise definition of current use, former use and quit attempt; and failure to utilize opportunity of direct data entry interface use during the survey to validate responses instantly. Redefining tobacco use and quit attempts considering an appropriate timeframe would reduce invalid responses.
authors.affiliation: Project STEPS, Public Health Foundation of India, New Delhi, and Heath Systems Research India Initiative, Bangalore, India E-mail : drpratapjena@gmail.com.
authors.forename: Pratap Kumar
authors.initials: PK
authors.lastname: Jena
authors.forename: Jugal
authors.initials: J
authors.lastname: Kishore
authors.forename: Sanghamitra
authors.initials: S
authors.lastname: Pati
authors.forename: Bidyut Kanti
authors.initials: BK
authors.lastname: Sarkar
authors.forename: Sagarika
authors.initials: S
authors.lastname: Das
mesh_terms: D000328:Adult; D005500:Follow-Up Studies; D015438:Health Behavior; D006306:Health Surveys; D006801:Humans; D011379:Prognosis; D064424:Tobacco Use / Q000523:psychology*; D020340:Tobacco Use Cessation / Q000523:psychology*; D014029:Tobacco Use Disorder / Q000517:prevention & control / Q000523:psychology*