“…The authors also acknowledge Thera-Business (Ontario CANADA) for providing their systematic review expertise to all study activities across all levels of the updated review process. Longest period of abstinence among current smokers (13), (14), (15), (16) Duration of most recent quit attempt among current smokers (15) Percent reporting longest quit time longer than 90 days among current smokers (17) Quit within past year vs. at least 1 year among former smokers (18) Quit between 3 months and 1 year; quit between 3 months and 5 years among former smokers (19) Time since quit (continuous measure) among former smokers (20), 21 (27) Tried to quit smoking in the past 12 months (28), (29), (30), (31), (32) At least 24 hours without smoking in the past 12 months because [respondent was] trying to quit smoking (25), (33), (34), (19), (35), (14), (12), (36) At least 24 hours without smoking ever because [respondent was] trying to quit smoking (14), (37) Intentionally abstained for at least 24 hours in the past 3 months (38), (39) At least 24 hours without smoking in the past 6 months (37) Any attempts (unde ned) to quit smoking [since previous interview] (40), 4124-hour abstinence (42) Use of a cessation program or aid (43), (27), (26), (32), (44) Other or de nition not reported (number of quit attempts) (45), (17),…”