Vetter 1990.

Study characteristics
Methods	Design: Randomized controlled trial Setting: A health center in a small town in the countryside, UK Recruitment: Postal questionnaire to practice patients
Participants	471 people who smoked aged 60 years and older, registered as a patient with the group practice; 48.0% F, av. age not reported, av. cpd not reported
Interventions	Intervention: Participants received physician advice and additional smoking cessation counseling by a practice nurse Control: Participants received physician advice only
Outcomes	PPA at 6m Validation: Expired CO, cut‐off not reported
Funding Source	The Grand Charity
Author's declarations of interest	Not reported
Notes	Strategy: Adjunctive counseling Level: Patient Comparison type: Single component vs. standard care
Risk of bias
Bias	Authors' judgement	Support for judgement
Sequence Generation	Unclear risk	No details reported
Allocation concealment	Unclear risk	No details reported
Blinding of outcome assessors All outcomes	Low risk	Abstinence was biochemically validated by carbon monoxide levels
Incomplete outcome data All outcomes	Unclear risk	QUOTE: "approximately 10% of subjects failed to respond to the second questionnaire". No further details were reported.