Nevid 1997.

Methods	Study design: Randomized controlled trial Country: USA Recruitment: Community volunteers, via media and healthcare settings Group size: 3 ‐ 12, single‐sex groups, same‐sex therapists
Participants	93 Hispanic smokers (excludes 56 people, 35 Gr, 21 S‐H who were randomized but did not attend any session and were not included in further analysis); 48% women, av. age 44, av. cpd 21 Therapists: bilingual Hispanic psychologists and social workers
Interventions	1. Group therapy. 8 x 2 hrs. Included videos using culturally‐specific components. Motivation, nicotine fading, quitting techniques, RP, 'buddy' support. TQD 5th week 2. S‐H with 1 group session for motivation and instructions and telephone contact. ALA Freedom from Smoking in 20 days in English & Spanish, also Guia para Dejar de Fumar Both conditions received same maintenance programme; ALA S‐H manual A Lifetime of Freedom from Smoking and 2 telephone calls a month for 6 m
Outcomes	Abstinence at 12 m (sustained from post‐treatment). PPA rates also reported Validation. Saliva cotinine
Notes	Comparison 1.1.2 vs different S‐H. Low take‐up rates. 33% of eligible attended orientation session, only 62% of enrollees attended any further session. Using 12‐m PPA rates would give 3/39 vs 4/54 quit
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"pairwise random assignment ... a random numbers table was used to generate a sequence of odd and even numbers, which was then used as the basis for randomly assigning members of each pair of consecutively enrolled participants within each gender to either [the treatment or control]"
Allocation concealment (selection bias)	Unclear risk	Seems unlikely from description that schedule was concealed
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Biochemical validation of abstinence
Incomplete outcome data (attrition bias) All outcomes	High risk	Post‐randomization dropouts are excluded. There was differential attendance