Ikonomidis 2020b.

Study characteristics
Methods	Design: RCT Setting:  Smoking Cessation Clinic of Second Cardiology Department of National and Kapodistrian University of Athens, Attikon General Hospital, Greece
Participants	40 Inclusion criteria: current smokers without cardiovascular disease
Interventions	EC type: NS Conventional cigarette (conv‐cig) or an electronic cigarette (e‐cig) with nicotine concentration 12 mg/dL for 1 month
Outcomes	a) Perfused boundary region (PBR) of the sublingual arterial micro vessels (range 5 – 25 micrometers), a marker inversely related with glycocalyx thickness  b) Pulse wave velocity (PWV), central systolic blood pressure (cSBP) and augmentation index (AIx)  c) Platelet function by 2 different methods, namely the novel Platelet Function Analyzer PFA‐100 and the traditional Light Transmission Aggregometry (LTA)  d) Exhaled CO level (ppm) as a smoking status marker e) Plasma malondialdehyde (MDA) levels, as an oxidative stress burden index
Study funding	Funding Acknowledgement: Type of funding source: None
Author declarations	NS
Notes	Information extracted from a conference abstract
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No detail given. Quote: "40 current smokers (mean age 48 years±5) without cardiovascular disease were randomized to smoke either a conventional cigarette (conv‐cig) or an electronic cigarette (e‐cig) (electronic cigarette fluid with nicotine concentration of 12 mg/dL) for one month."
Allocation concealment (selection bias)	Unclear risk	NS
Blinding of participants and personnel (performance bias) All outcomes	High risk	No blinding
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	NS
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	NS
Selective reporting (reporting bias)	High risk	Results reported in summary form, not fully, with only some significant changes reported. Information taken from a conference abstract only