Tobacco Use and Quit Behaviour Assessment in the Global Adult Tobacco Survey (GATS): Invalid Responses and Implications

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 inherentpolicy implications for tobacco cessation programme evaluation. This study aimed to review the concepts of quitattempt assessment and quantifying invalid responses considering GATS-India data. Materials and
Methods:GATS assessment of tobacco use and quit attempts were examined in the current literature. Two categories ofinvalid responses were identified by stratified analysis of the duration of last quit attempt among current usersand duration of abstinence among former users. Category A included absolute invalid responses when timeframeof assessment of current tobacco use and less than former tobacco use were violated. Category B includedresponses that violated the unit of measurement of time.
Results: Current daily use, current less than daily use andformer use in GATS were imprecisely defined with overlapping of time-frame of assessment. Overall responses of3,102 current smokers, 4,036 current smokeless users, 1,904 former smokers and 1,343 former smokeless userswere analyzed to quantify invalid responses. Analysis indicated overall 21.2% (category A: 7.32%; categoryB: 17.7%) and 22.7% (category A: 8.05%; category B: 18.1%) invalid responses among current smokers andsmokeless users respectively regarding their duration of last quit attempt. Similarly overall 6.62% (categoryA: 4.7%; category B: 2.3%) and 10.6% (category A: 8.6%; category B: 3.5%) invalid responses were identifiedamong 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 andquit attempt; and failure to utilize opportunity of direct data entry interface use during the survey to validateresponses instantly. Redefining tobacco use and quit attempts considering an appropriate timeframe wouldreduce invalid responses.