Assessment
PMT
All participants in the two groups were instructed to attend face-to-face follow-ups with research staff at one, three, and six months after randomisation. The outcomes were as follows:Frequency reduction – achieved when a daily smoker (at baseline) had not successfully quit according to the evaluation of biochemically verified six-month sustained abstinence rate, but had reduced the smoking frequency to weekly smoking and maintained that smoking frequency during the follow-up period.Smoking amount reduction – achieved when a daily smoker (at baseline) had not successfully quit according to the evaluation of biochemically verified six-month sustained abstinence rate, but had continuously reduced the smoking amount or reduced to a lower level and maintained the lower level during the follow-up period.Changes in PMT construct scores, including perceived severity, perceived vulnerability, intrinsic rewards of smoking, extrinsic rewards of smoking, self-efficacy of quitting, response efficacy of quitting, and response cost of quitting.