Schlam 2016.

Study characteristics
Methods	Study design: factorial RCT Country: USA Recruitment: smokers attending primary care clinics were invited to participate in a research programme to help them quit smoking. Electronic health record technology prompted clinic staff to invite smokers to participate
Participants	544 smokers; aged ≥ 18 years, ≥ 5 cigarettes per day for 6 months, motivated to quit 41% men, average age 46.2, average cigarettes per day 18.6, mean FTND 4.9, HSI 3.2, baseline CO 18.5 ppm
Interventions	2 x 2 x 2 x 2 x 2 factorial design. There were 5 intervention components tested (detailed below) that were tested in different combinations resulting in 32 study groups. 1) Nicotine patches and gum for 8 weeks starting on quit date versus nicotine patches and gum for 26 weeks starting on quit date 2) Maintenance counselling versus no maintenance counselling 3) Medication adherence counselling versus no medication adherence counselling 4) Automated adherence calls versus no adherence calls 5) Helping Hand medication dispenser with feedback and counselling versus no medication dispenser, feedback or related counselling For the purposes of this review, we are only interested in comparison 1.
Outcomes	Self‐reported 7‐day PPA at 52 weeks post‐quit date Validation: none Other abstinence measures: self‐reported 7‐day PPA at 26 weeks post‐quit date Adverse events: measured at 1, 4 and 8 weeks by completed assessments with case managers (and at 16 weeks if receiving extended medication). Also measured at weeks 16, 26, 39 and 52 during follow‐up calls with assessors
Notes	The study was funded by grants 9P50CA143188 and 1K05CA139871 from the National Cancer Institute. Conflicts of interest: "The authors have received no direct or indirect funding from, nor do they have a connection with, the tobacco, alcohol, pharmaceutical or gaming industries or anybody funded substantially by one of these organizations. W.‐Y.L. is supported partially by a grant from Eli Lilly and Company for research that is unrelated to smoking or tobacco dependence treatment." This study has a factorial design and statistical interactions between factors were reported in the paper. Authors supplied group‐by‐group data. We checked to see if the odds ratios generated from these raw data were significantly, clinically different from those generated for the regression model adjusting for interactions in the paper, for comparison 1. The odds ratios were similar, but the wider confidence intervals generated from the raw data changed the interpretation of the results. The analysis accounting for interactions in the paper resulted in a significant effect of 26‐week gum, but this effect was found to be non‐significant when using raw data from the authors. We therefore have not entered raw data, supplied by authors, into any analysis. We have reported this study narratively in the main text.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: “Participants were randomized to one of 32 unique experimental conditions… via a database that used stratified, computer‐generated, permuted block randomization…”
Allocation concealment (selection bias)	Low risk	Quote: “Staff could not view the allocation sequence. The database did not reveal participants’ treatment condition to staff until participants’ eligibility was confirmed; participants were blinded to treatment condition until they provided consent.”
Blinding (performance bias and detection bias) All outcomes	High risk	No placebo used, therefore participants were not blinded to treatment condition. Assessors were not involved in treatment but were not blinded to treatment assignment
Incomplete outcome data (attrition bias) All outcomes	Low risk	Attrition: 127/275 extended NRT, 129/269 standard NRT. < 50%, similar in both groups