Table 1

Data extraction fields

Study detailsExtraction formatConsidered as an independent variable
AuthorFirst author last name
YearYear published
TitleTitle of publication
CountryFrom text
Years of studyYear/s study was conducted
Funding sourceFrom text
Conflict of interestsFrom text
Study designRCT, cluster RCT
Aims of studyFrom text
Years of recruitmentYears
Method of recruitmentFace-to-face, social media, random-digit dialling;; snowball recruiting; use of social networks; advertisements, media or notices ; identification of potential participants through public registries, medication record and so onYes
Recruitment settingHospital, community healthcare, primary care, non-government organisation (NGO), otherYes
Recruiter qualifications, training and professional roleYes
Familiarity of recruiter to participantUnknown (eg, external researcher), limited previous contact (eg, staff member in hospital), regular clinician, peer, otherYes
Retention strategy employedYes/no; typeYes
AgeMean (standard deviation), median (range)Yes
GenderMale, female, other/unspecified.Yes
Race/ethnicityFrom textYes
Socio-economic statusEmployment status, level of education or similarYes
Mental health diagnosisType of mental illness/es of participantsYes
Severity of distress/ mental health disorderDASS-21, Kessler 10, Global Assessment of Functioning (GAF) or similar measuresYes
Inclusion/exclusion criteriaFrom text
Current smoker definitionDaily, weekly, occasional smokerYes
Cigarette consumption (baseline)Mean (standard deviation), median (range)Yes
Nicotine dependence (baseline)Fagerstrom Test of Nicotine Dependence (FTND) or similar measuresYes
Motivation to quit (baseline)Readiness and Motivation to Quit Smoking Questionnaire or similar measuresYes
Requirement to set a quit date on recruitmentYes/noYes
Treatment typePharmacotherapy, psychoeducation, cognitive and behavioural therapies, staff training, other
Dosage (if applicable)
Number of session (where applicable)
Facilitator qualifications and trainingFrom text
Mode of deliveryFace-to-face, telephone, online, mail, individual and/or group, other
Description of comparatorPlacebo, no treatment, waitlist, usual care, other smoking cessation/reduction intervention, other
Primary outcomesSpecified and collected
Secondary outcomesSpecified and collected
Definition of abstinenceFrom text
Definition of smoking reductionFrom text
Type of biochemical validation (if applicable)Carbon monoxide (CO), cotinine, otherYes
Timing of follow-up assessmentsMonthsYes
Mode of follow-up assessmentFace-to-face, telephone interview, postal or electronic survey and so onYes
Follow-up setting (if applicable)Yes
Potential costs to participant associated with follow-up assessmentsAbsence from work, fuel and parking costs and so onYes
Intention to treat and per protocol analyses conductedYes/no
Risk of bias
Method of randomised sequence generation
Method of allocation concealment
Blinding of participantsYes/noYes
Blinding of research staffYes/noYes
Blinding of outcome assessorsYes/noYes
Levels of loss to follow-up
Reporting of loss to follow-up
GRADE GRADE methodology rating