Whittaker 2011.

Methods	Study design: RCT Country: New Zealand Recruitment: targeted at young people through advertising via radio, Internet, mobile phone, paper‐based and online magazines, Maori‐specific media of all types, local and national newspapers and media releases to national media outlets, tertiary education institutions, primary healthcare services, SC services, large employer health promotion programmes, and posters at cafes/bars/sports/grounds Study dates: 2007‐09
Participants	Baseline characteristics (n = 226) Mean age: 27 years Female: 47.3% Less than high school: not stated Time to first cigarette 5 min: 23% (N = 52) White: 52.2% NZ European Inclusion criteria: ≥ 16 years, current daily smokers ready to quit, and had a video message‐capable phone. Exclusion criteria: not explicitly stated
Interventions	Intervention: received an automated package of video and text messages over 6 months that was tailored to self‐selected QD, role model and timing of messages. Video messages were video diary‐style from a selected 'ordinary' person going through a quit attempt in advance of the participant. Frequency of messages varied from 1/day in the lead up to QD, 2/day from QD for 4 weeks, then reducing to 1 every 2 days for 2 weeks and then 1 every 4 days for about 20 weeks until 6 months after randomisation. Extra messages were available on demand to beat cravings and address lapses. Additional website for intervention group participants to review video messages they had been sent (and rate them if desired), change their selected time periods and change (or add to) their selected role model. Control: set a QD and received a general health video message sent to their phone every 2 weeks
Outcomes	Definition of abstinence: self‐reported continuous abstinence at 6‐month follow‐up
Funding source	Health Research Council of New Zealand. It was supported by Vodafone NZ who provided free access to their mobile phone network but was otherwise uninvolved. The intervention was previously funded by the Digital Strategy Community Partnership Fund, Dept of Internal Affairs, NZ
Conflicts of interest	None declared
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Central computerised randomisation
Allocation concealment (selection bias)	Low risk	Baseline data collected online, with computer randomisation on submission of form, and programme automatically assigned ‐ no study staff involved
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Contact with investigators was minimal in both groups
Incomplete outcome data (attrition bias) All outcomes	Low risk	32% intervention and 22% control lost to follow‐up at 6 months