Bosilkovska 2020.

Study characteristics
Methods	Design: RCT Study dates: January 2016 to August 2016 Recruitment: from clinic's database and advertisements Location: Warsaw, Poland Setting: in a clinic for 5 days then an ambulatory setting for following 85 days
Participants	Number randomised: 120 Characteristics: 46.7% women; mean age 38.9 years; 45.0% smoked 10–19 cigarettes per day, while 55.0% smoked > 19 cigarettes per day; mean FTND score 5.3 Specialist population: aged ≥ 28 years; Caucasian Inclusion criteria Healthy Verified current smoker (≥ 10 non‐menthol cigarettes per day for past 6 weeks) Aged ≥ 28 years Caucasian origin Smoked for previous ≥ 10 years No intention to quit smoking in the next 6 months Exclusion criteria Medical conditions that were a safety concern or would interfere with study BMI < 18.5 or ≥ 32 kg/m2 Use of nicotine‐containing products other than cigarettes in 6 weeks prior to admission Use of drugs likely to affect CYP1A2 or CYP2A6 activity within 14 days or 5 half‐lives of the drug (whichever was longer) before admission Current or past alcohol problems Positive urine drug test Given or received blood in 3 months prior to admission Current or past employee of the tobacco industry or their close relatives Pregnant or breastfeeding People of childbearing potential who do not agree to use contraception
Interventions	Randomised (2:1 ratio) to use a carbon tip HTP or continue smoking cigarettes Heated tobacco arm Device heating method: carbon tip Device name: CHTP 1.2 Device manufacturer: PMI Other instructions and details: CHTP products were provided to participants randomised to heated tobacco arm Behavioural support: record use of nicotine and tobacco products in electronic diary. 5 days in clinic setting Instructions for smoking cessation/switching: only use CHTP HTP for study period  Cigarette smoking arm Behavioural support: record use of nicotine and tobacco products in electronic diary. 5 days in clinic setting Instructions for smoking cessation/switching: continue smoking cigarettes
Outcomes	Follow‐up time points: 13 weeks Abstinence outcomes: N/A Safety outcomes: biomarkers of toxicant and carcinogen exposure; biomarkers of harm; adverse events; serious adverse events
Notes	Funding source Tobacco industry funded: quote: "Philip Morris International is the sole source of funding and the sponsor of this study". Author conflicts of interest Quote: "All authors are employees of Philip Morris International (PMI) or work for PMI under contractual agreements".
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No details on random sequence generation.
Allocation concealment (selection bias)	Low risk	Protocol mentions that: "At the end of the baseline period enrolled subjects will be randomized using an interactive web and voice response system (IxRS) on day −1 at any time during the day".
Blinding of outcome assessment (detection bias) All outcomes	Low risk	All outcomes were biological and assessors were blinded to randomised group allocation.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Low attrition in both groups, 76/80 participants in heated tobacco arm and 39/40 in cigarette arm completed final follow‐up.
Selective reporting (reporting bias)	Low risk	All preregistered outcomes reported.