| Methods |
Country: USA
Setting: telephone smoking cessation helpline
RCT. Randomised by day of the week, but counsellors blinded to the guide being used |
| Participants |
630 smoking mothers with children younger than 6 years of age calling the helpline |
| Interventions |
Callers to a telephone smoking cessation assistance service were randomised to receive 1 of 3 self‐help guides. One was specifically written for the target audience, another was received from the American Lung Association, and 1 was developed by the National Cancer Institute. Callers to the line received individual stage‐based counselling and were sent the guide by mail. |
| Outcomes |
Six months later, the participant was called and was interviewed for 10 minutes about the use of the guide, opinion of the guide, quit attempts and strategies to quit, and current smoking. |
| Type of intervention |
Community‐based |
| Notes |
Retention: 630/873 (72%) |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
High risk |
Quasi‐randomised: "Guides were assigned randomly to those in the target audience based on a preassigned list randomized by the day of the week." |
| Allocation concealment (selection bias) |
Low risk |
"CIS counsellors were blinded regarding which self‐help guides subjects would receive." |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
28% lost to follow‐up; "completion rates were similar for subjects in the three guide groups" |
| Blinding of outcome assessment (detection bias)
All outcomes |
Low risk |
"Follow‐up interviews were conducted by trained interviewers who were blinded regarding subject assignment.... Surrogate interviews were conducted to verify the smoking status of those who reported that they had quit smoking..." |
