| Methods |
Country: UK (95 centres)
Recruitment: hospital chest clinics (80%) and inpatient wards |
| Participants |
1618 clinic patients age 18 to 65 with a smoking‐related illness (pulmonary or vascular)
39% female, average age 49, average cpd 24 |
| Interventions |
1. Brief advice from physician
2. Brief advice + booklet
3. Brief advice + booklet + placebo chewing gum
4. Brief advice + booklet + nicotine chewing gum (2 mg for up to 3 months, up to 6 months on request)
Level of support: low (1 month and 3 month follow‐up visits) |
| Outcomes |
Sustained validated abstinence at 6 months and 12 months
Validation: Venous carboxyhaemoglobin |
| Notes |
Includes both placebo and no‐placebo groups. 4 vs 1 + 2 + 3 used in main comparison. 4 vs 3 has lower OR (0.8) but does not alter MA notably
Study was funded by Health Education Council and Lundbeck Ltd |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Each physician had a balanced block of 12 treatments. Assignment was by numbered envelope |
| Allocation concealment (selection bias) |
Low risk |
Physician opened envelope at first treatment session |
| Blinding (performance bias and detection bias)
All outcomes |
Low risk |
Quote: "Placebo and nicotine gums were indistinguishable in appearance and taste, and neither the physician nor the patient knew which gum had been issued" |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
Lower losses from gum groups (10 and 10) than from Advice groups (24 and 24), but 18 VA and VAB participants were prescribed Nicorette in error; removing these made differences non‐significant |
