Carmody 2008.
Methods | Site: USA, San Francisco Veterans Affairs Medical Center. Study period: September 2001‐December 2003. Recruitment: participants enrolled from the medical centre, referral practice to the medical centre is unknown. Sample size calculation: not mentioned. | |
Participants | Number of participants: 286 smokers (hypnosis plus nicotine patch: 145; behaviour plus nicotine patch: 141). Inclusion criteria: current smokers interested in quitting (Stages of Change model, contemplation or action stage of quitting) and reported smoking ≥ 10 CPD during the pre‐enrolment week. Exclusion criteria: NRT contraindication. Overall demographics: predominantly unmarried, white, middle‐aged; smoked 20 CPD on average. | |
Interventions | a) Hypnosis (training based on Spiegel (1994), Lynn et al. (1993), Green (1996, 1999) and Gorassini and Spanos (1986) + audiotape of hypnosis training to use daily at home).
b) Behavioural counselling based on social learning theory & Stages of Change model. Both groups received 2 x 60 mins face‐to‐face sessions + 3 x 20 mins follow‐up telephone counselling calls at weeks 3, 4 & 6 + 2 months supply of nicotine patch (initial dose: 21 mg or 14 mg). Duration of intervention: 2 months. |
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Outcomes | Definition of smoking cessation: point‐prevalence abstinence (defined as no smoking, not even a puff, for 7 days) at telephone follow‐up at 6 and 12 months. Adverse events: no information provided on whether or not AE data were collected and whether any AEs occurred. | |
Notes | Funding: California Tobacco‐Related Diseases Research Program. The funding agency had no role in the conduct of the research or preparation of the manuscript. Author declaration of interest: not reported. |
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Risk of bias | ||
Bias | Authors' judgement | Support for judgement |
Random sequence generation (selection bias) | Low risk | Randomized, using computer‐generated algorithm (SPSS, V.15) (information from author) |
Allocation concealment (selection bias) | Low risk | Subject numbers and the corresponding treatment assignments in sequentially numbered and sealed opaque envelopes. As each subject enrolled in the study, the study co‐ordinator supplied their counsellor with the envelope to open at the start of the first counselling session (information from author). |
Blinding of outcome assessment (detection bias) All outcomes | Low risk | The research associates who telephoned subjects for study follow‐up assessments were not blinded to their treatment condition, but biochemical confirmation of quitting was done by lab personnel blinded to treatment assignment. |
Incomplete outcome data (attrition bias) All outcomes | Low risk | At 6 months:
a) Hypnosis: dropout: 4; withdrew: 1; died: 1; lost to follow‐up: 7
b) Behaviour: dropout:12, withdrew: 1; lost to follow‐up: 4
At 12 months (cumulative):
a) Hypnosis: dropout: 4; withdrew: 1; died: 4; lost to follow‐up: 11
b) Behaviour: dropout: 12; withdrew: 2; died: 1; lost to follow‐up: 5 Lost to follow‐up and withdrawn participants were included in the original analysis, with the imputation of being smokers at the endpoints, but 'dropout' patients were not included in the original analysis. The behaviour group 'dropout' (those who did not attend the second session of treatment) rate was 3 times that for the hypnosis group. We included all patients (i.e. 'dropout', withdrew, LTFU), except those who died, in our recalculations for ITT analyses (missing assumed smoking). |
Selective reporting (reporting bias) | Low risk | All outcomes reported as described in the methods section. |