Feasibility and Acceptability of a Text Messaging Intervention to Increase Smoking Cessation in Vietnam

For two-arm randomized control (RCT) pilot study (AIM 3), 100 current smokers will be
observed to examine the preliminary effect of bidirectional SMS smoking cessation
intervention. Subjects will be randomized into two groups (intervention vs. control), and
compare the carbon monoxide (CO) validated 7-day point prevalence smoking abstinence rates at
4-week follow-up between intervention group (SMS smoking cessation treatment) and control
group (assessment texts only).

Investigators will administer surveys at baseline, 4- and 12-weeks, and assess daily
cigarette consumption using text message surveys. After the intervention, they will randomly
select 10 participants from the intervention group to attend semi-structured interviews to
obtain more in-depth understanding about the usefulness, usability, and acceptability of the
intervention. Findings from the pilot RCT will be used to derive an estimate of the effect
size, power, and sample size for a full-scale efficacy trial.

Inclusion Criteria:

- smoke ≥10 cigarettes per day

- capability to read and communicate

- plan to quit in the next 30 days

- has a mobile phone

- has experience using mobile phone text messaging during the past 6 months.

Exclusion Criteria:

- Under smoking cessation treatment or is participating in other tobacco cessation
intervention

- pregnant or breastfeeding.