| Methods |
Setting: hospital chest clinics and inpatient wards, UK
Recruitment: patients with smoking‐related conditions |
| Participants |
748 smokers (in relevant arms), average age 49, average cpd 24 |
| Interventions |
∙ Brief advice to quit from a physician
∙ Advice and self‐help booklet containing information and advice
∙ Same as second bullet here plus placebo chewing gum (not included in this review)
∙ Same as second bullet here plus nicotine gum (not included in this review) |
| Outcomes |
Sustained abstinence 6 to 12 months (2 months point prevalence)
Validation: venous carboxyhaemoglobin and thiocyanate |
| Notes |
2 vs 1, self‐help vs control. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Centrally generated; "each physician initially received a balanced block of 12 treatments" |
| Allocation concealment (selection bias) |
Low risk |
Numbered envelopes, opened after eligibility assessed |
| Blinding (performance bias and detection bias)
All outcomes |
Unclear risk |
Biochemical validation, but possible performance bias in that physicians handing out leaflets were not blind to treatment condition and this may have impacted advice; insufficient detail reported by which to judge |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
48 withdrawals re‐included in this analysis with no impact on effect size |
