Hill 1993.

Methods	Country: USA Recruitment: community volunteers, smoking at least 30 yrs, not currently walking for exercise Randomisation: in blocks of 8 to 12, method not described
Participants	82 (43 women, 39 men), mean age 59, mean CPD 28, irregular walkers
Interventions	(a) Intervention 1: Walk: group/individual, facility/home, 15 ‐ 35 mins, 60% ‐ 70% HR reserve, 1 ‐ 3 times/week for 12 weeks (n = 20) (b) Intervention 2: as (a) + CP 1 ‐ 4 times/week for 12 weeks (n = 18) (c) Intervention 3: CP as (b) + nicotine gum (n = 22) (d) Control: CP alone (n = 22) Exercise began before quit date
Outcomes	5‐day PPA Validation: CO < 10 ppm Follow‐up: 1, 4, 9 months
Notes	(b) compared to (d) for effect of exercise programme Funding: Information not provided Conflict of interest: Information not provided
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not stated
Allocation concealment (selection bias)	Low risk	No details given
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Details of blinding not specified, but as self‐reports of smoking were validated objectively by expired CO risk is considered as low
Incomplete outcome data (attrition bias) All outcomes	Low risk	4 individuals dropped out and were excluded from the analysis. The main findings were the same with or without the 4 dropouts
Selective reporting (reporting bias)	Low risk	Smoking outcomes reported as stated in Methods