Table 1.

Characteristics of included studies

Author, year, country	n	Population	Design	Outcomes measured
Ashley and Cohen, 2003, Canada54	1607	Adult: 18+ years	Cross-sectional	Attitudes towards tobacco industry (TI)
Austin et al, 2005, USA23	119	Youth: 15–25 years	Controlled before and after	Current smoking prevalence†; intent to smoke‡; perceived peer prevalence
Bauer et al, 2000, USA15	20 978–23 745	Youth: 12–17 years	Repeated cross-sectional (three waves)	Current smoking prevalence§; intent to smoke¶
Carver et al, 2003, USA62	800, 790	Adult: 18+ with children	Historically controlled	Attitudes towards TI
Cowell et al, 2009, USA37	31 785	Youth: 12–17 years	Repeated cross-sectional (seven waves)	Intent to smoke**
Danishevski et al, 2008, Russia58	1600	Adult: 18+ years	Cross-sectional	Attitudes towards TI
Davis et al, 2007, USA50 Farrelly et al, 200935	35 074	Youth: 12–17 years	Repeated cross-sectional (eight waves)	Intent to smoke; perceived peer smoking prevalence
Davis et al, 2009, USA27	16 327	Youth: 12–17 years	Longitudinal	Smoking initiation; intent to smoke¶
Dietz et al, 2008, USA45 Delva et al, 200944	2374	Adult: 18+ years	Cross-sectional	Intent to quit smoking
Dietz et al, 2010, USA16	14 400	Youth: 12–17 years	Repeated cross-sectional (eight waves)	Current smoking prevalence†
Dixon et al, 2001, Australia42	323 prior to study, 266 post study	Adult/youth: 15–60 years	Controlled before and after	Intent to smoke††; attitudes towards TI
Dunn et al, 2004, USA32	852	Youth: 15–17 years	Cross-sectional	Intent to smoke*; empowerment
Dunn and Pirie, 2005, USA53	940	Youth: 12–25 years	Cross-sectional	Empowerment
Durkin et al, 2005, Australia55	1995–3001	Adult: 18+ years	Repeated cross-sectional (three waves)	Attitudes towards TI
Edwards et al, 2007, Australia43	3091	Youth: 12–25 years	Historically controlled	Intent to smoke††
Evans et al, 2002, USA70 Evans et al, 200571	2306	Youth: 12–17 years	Repeated cross-sectional (two waves)	Structural equation modelling
Evans et al, 2004, USA72	10 412	Youth: 12–17 years	Repeated cross-sectional (three waves)	Structural equation modelling
Farrelly et al, 2002, USA28	3439–6233	Youth: 12–17 years	Repeated cross-sectional (two waves)	Intent to smoke**
Farrelly et al, 2005, USA22	43 922	Youth: 12–17 years	Historically controlled	Current smoking prevalence†
Farrelly et al, 2009, USA28	8904	Youth: 12–17 years	Longitudinal	Smoking initiation; intent to smoke**
Hammond et al, 2006, Canada/US/UK/Australia8, Young et al, 200746	8222–9058	Adult: 18+ years, smoker*	Repeated cross-sectional (three waves)	Intent to quit; attitudes towards TI
Henriksen and Fortmann, 2002, USA66	218	Young adult: 18–25 years	Randomised controlled trial	Attitudes towards TI
Hersey et al, 2003, USA68	6875	Youth: 12–25 years	Cross-sectional	Structural equation modelling
Hersey et al, 2005, USA19	34 946	Youth: 12–17 years	Repeated cross-sectional (five waves)	Current smoking prevalence†
Hersey et al, 2005, USA67	16 464	Youth: 12–17 years	Repeated cross-sectional (three waves)	Structural equation modelling
Hudson et al, 2007, New Zealand65	10	Adult: 18 years	Qualitative interviews	Attitudes towards TI
Johnson et al, 2008, USA60	28	Youth: 12–14 years	Qualitative focus groups	Attitudes towards TI
Kim and Nam, 2005, USA63	22	Adult: 18 years*, smoker	Qualitative focus groups	Attitudes towards TI
King et al, 2007, USA61	410	Adult: 18+ years*	Cross-sectional	Attitudes towards TI
Klesges et al, 2009, USA26	36 013 prior to study, 20 672 post study	Adult: Air Force Recruits	Longitudinal	Current smoking prevalence§; smoking initiation
Leatherdale et al, 2006, Canada21	14 767	Youth: 14–18 years	Cross-sectional	Current smoking prevalence§
Ling et al, 2007, USA24	9455	Young adult: 18–29 years	Cross-sectional	Current smoking prevalence†; intent to quit; intent to smoke**
Ling et al, 2009, USA25	1731	Young adult: 18–29 years	Cross-sectional	Current smoking prevalence†‡‡; intent to quit
Murphy-Hoefer et al, 2008, USA47 Murphy-Hoefer et al, 2010, USA48	1011	Young adult: 18–24 years	Controlled experiment	Intent to quit
Netemeyer et al, 2005, USA49	1207	Adult: 18+ years, smoker	Cross-sectional	Intent to quit
Niederdeppe et al, 2004, USA17	7478	Youth: 12–17 years	Repeated cross-sectional (three waves)	Current smoking prevalence†; intent to smoke**
Niederdeppe et al, 2008, USA31	5010	Youth: 12–18 years	Repeated cross-sectional (five waves)	Intent to smoke‡
Pechmann et al, 2003, USA38	1667	Youth: 15–18 years	Randomised controlled trial	Intent to smoke*; resistance self-efficacy
Pechmann et al, 2006, USA39	1725	Youth: 14–15 years	Randomised controlled trial	Intent to smoke*; empowerment
Reinert et al, 2010, USA64	53	Adult: School nurses	Cross-sectional	Attitudes towards TI
Richardson et al, 2010, USA41	19 701	Young adult: 18–24 years	Repeated cross-sectional (eight waves)	Intent to smoke**; intent to quit
Shadel et al, 2009, USA51 Shadel et al, 2010, USA52	110	Youth: 11–17 years	Controlled comparison	Resistance self-efficacy
Sly et al, 2000, USA59	1816	Youth: 12–17 years	Cross-sectional	Attitudes towards TI
Sly et al, 2001, USA30	1820	Youth: 12–17 years	Repeated cross-sectional (two waves)	Smoking initiation
Sly et al, 2001, USA18	Approximately 1800	Youth: 12–17 years	Repeated cross-sectional (four waves)	Current smoking prevalence§
Sly et al, 2002, USA29	1805	Youth: 12–17 years	Repeated cross-sectional (six waves)	Smoking initiation
Sly et al, 2005, USA33	1079–1150	Youth: 12–17 years	Repeated cross-sectional (four waves)	Intent to smoke**
Sutfin et al, 2008, USA40	488	Youth: 15–17 years	Randomised controlled trial	Intent to smoke*
Tangari et al, 2007, USA34	1208 adult, 900 youth	Adult/youth	Cross-sectional	Intent to smoke*; intent to quit
Thrasher and Jackson, 2006, USA69	6670	Youth: 12–17 years	Repeated cross-sectional (two waves)	Structural equation modelling
Thrasher et al, 2006, USA20	10 035	Youth: 12–17 years	Repeated cross-sectional (two waves)	Current smoking prevalence†; intent to smoke*
Wakefield et al, 1999, Australia56	808	Adult: 18+ years	Cross-sectional	Attitudes towards TI
Waller et al, 2004, Canada57	10 434, youth, 1607 adult	Adult/youth: 12–18 years	Repeated cross-sectional (three waves)	Attitudes towards TI
Zucker et al, 2000, USA14	1247–1806	Youth: 12–17 years	Repeated cross-sectional	Current smoking prevalence

^*Intent to smoke measured with three validated items on a five-point Likert scale: ‘in the future, you might smoke one puff or more of a cigarette’; ‘you might try out cigarette smoking for a while’; ‘if one of your best friends were to offer you a cigarette you would smoke it’.

^†Current smoking prevalence measured using 30 day referent.

^‡Intent to smoke measured with one item on a four-point or seven-point scale: ‘if your best friend offered you a cigarette, would you smoke it?’.

^§Current smoking prevalence measured on 3–5 classification continuum: never smoker, experimenter, ever smoker, current smoker, former smoker.

^¶Intent to smoke measured with four items on a five-point scale: ‘do you think you will smoke a cigarette soon?’; ‘do you think you will smoke a cigarette anytime during the next year?’; ‘do you think you will be smoking cigarettes 5 years from now?’; ‘if one of your best friends offered you a cigarette would you smoke it?’.

^**Intent to smoke measured with one item on a four-point Likert scale: ‘you will smoke a cigarette in the next year’.

^††Intent to smoke measured with one item on a seven-point scale: ‘do you think you will be smoking cigarettes this time next year?’.

^‡‡Current smoking prevalence measured using 100-cigarettes referent.