| Methods |
Design: four group parallel trial
Purpose: examine the effect of behaviour therapy, hypnosis and placebo on smoking cessation |
| Participants |
Patients: smokers wanting to quit
Baseline comparability: yes |
| Interventions |
Placebo: sessions with general discussions of topics of concern to the participant
Untreated: no sessions
Experimental:
‐hypnosis sessions: negative aspects of smoking were repeated while patient was in trance
‐behavioural therapy sessions: focused smoking technique where participants were to concentrate on the aversive aspects of smoking
(Co‐intervention: NS) |
| Outcomes |
Number of abstinent smokers (based on thiocyanate concentration)
Number of abstinent smokers (based on self report)
Mean smoking rate |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
NS |
| Allocation concealment? |
Unclear risk |
NS |
| Blinding?
Treatment provider |
High risk |
Not described as double‐blind (placebo/behaviour therapy) |
| Blinding?
Outcome assessor |
Unclear risk |
NS |
| Incomplete outcome data addressed?
All outcomes |
Low risk |
Drop‐out < 15% |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
Unclear risk |
Not relevant (binary outcome) |
| Trial size > 49? |
High risk |
N = 30 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Trial size < 49 |
