Chen 2020.
| Study characteristics | ||
| Methods | Country: USA Aim: to compare the efficacies of cNRT and varenicline with one another and with placebo, as a function of the rs16969968 genotype Dates: May 2015‐August 2019 Study design: genotype‐stratified randomised, double‐blind, placebo‐controlled clinical trial |
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| Participants | 822 current smokers, smoking > 5 CPD, with exhaled CO ≥ 8 ppm. 54.6% female, mean age 46.5, baseline average CPD 17.6 | |
| Interventions |
Randomisation was stratified by rs16969968 genotype in blocks of 6 patients (2 per treatment per block) |
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| Outcomes | Primary: 7‐day PPA at week 12 Secondary: 7‐day PPA with CO verification at 6 months; 7‐day PPA at 1 year by self‐report; AEs, and adherence Abstinence was defined as no self‐reported smoking for at least 7 days before the assessment with biochemical verification (CO < 8 ppm) for those self‐reporting abstinence. |
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| Notes | New for 2022 update Funding by National Institute on Drug Abuse, Siteman Cancer Center and NCI Cancer Center Support Grant. Pfizer supplied the study medication free of charge. Author declaration of interests: "L.‐S.C. received free supply of study medication (varenicline and placebo) for this research project via an investigator‐initiated research agreement (IIR) from Pfizer. This free Pfizer product constitutes the support for this study. Pfizer supports the Principal Investigator to exercise the academic freedom and encourages publication of study results whether or not they are favorable for the Pfizer Product. R.M.C. or a member of his family owns stock in Pfizer Inc. L.J.B. is listed as an inventor on Issued US Patent 8,080,371 “Markers for Addiction” covering the use of certain single nucleotide polymorphisms in determining the diagnosis, prognosis, and treatment of addiction, and served as a consultant for the pharmaceutical company Pfizer Inc. (New York City, NY) in 2008. The spouse of N.L.S. is also listed as an inventor on Issued US Patent 8,080,371 “Markers for Addiction.” All other authors declared no competing interests for this work." |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "SAS Version 9 statistical software will be used to generate the random assignment table stratified by CHRNA5 genotype rs16969968" From protocol |
| Allocation concealment (selection bias) | Low risk | "The group assignment and genotype will be coded to ensure that the double blind is maintained, and the interface will prevent staff from having access to the participant’s assignment and genotype until after the baseline and post treatment assessments have been completed." |
| Blinding (performance bias and detection bias) All outcomes | Low risk | Placebo‐controlled and matched contact between groups |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Attrition < 50% and similar between arms |
| Selective reporting (reporting bias) | Low risk | Results for all prespecified outcomes reported |