Eisenberg 2016
| Methods | Country: 40 centres in USA and Canada Setting: Hospitals Aim: To determine the efficacy and safety of varenicline for increasing smoking abstinence rates through smoking reduction Study Design: Double‐blind placebo‐controlled multicentre RCT Study name: Evaluation of varenicline in smoking cessation for patients post‐acute coronary syndrome (EVITA) Dates conducted: not stated Analysis: "The sample size was estimated assuming a 7 day point prevalence abstinence rate of 24% at 24 weeks in patients receiving placebo.With this assumption, 150 patients per study arm would achieve a >80% power to identify a >15% absolute increase in abstinence rates (24% to 39%) using a two‐tailed α of 0.05". |
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| Participants | 302 adult smokers, aged 18+, smoking 10+ CPD, interested in trying to quit, hospitalised in USA or Canada for acute coronary syndrome (MI or unstable angina). Mean age 55, 25% women, mean CPD 21.5 Allocated to varenicline (151) or placebo (151) Exclusions: Excessive alcohol, history of panic disorder, psychosis, bipolar disease, dementia, renal or hepatic impairment, current or recent drug use, history of suicidal ideation/attempt or family history of suicide |
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| Interventions | 1. Varenicline 12 wks, titrated 1st wk 2. Placebo 12 wks, titrated 1st wk Medication was begun in hospital. All participants received low‐intensity counselling Follow‐up at wks 1, 2 and 8 by phone, and clinic visits at wks 4, 12 and 24 |
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| Outcomes | Primary: 7‐day PPA at wk 24 Secondary: CAR at all follow‐up visits, 7‐day PPA at other follow‐up visits, ≥ 50% reduction in CPD Measures of side effects and SAEs Validation: CO ≤ 10 ppm |
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| Treatment type | Medication: VARENICLINE | |
| Notes | New for 2016 update Funded by Pfizer | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "Patients were randomized to either varenicline or matching placebo... Randomization was performed by enrolling center personnel and stratified by center using a computer‐generated list of permuted blocks of 2 and 4" |
| Allocation concealment (selection bias) | Unclear risk | Not stated |
| Blinding (performance bias and detection bias) All outcomes | Unclear risk | Described as "double‐blind", but no further detail |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Losses fully reported; ITT analyses conducted |
| Selective reporting (reporting bias) | Low risk | None noted |
| Other bias | Low risk | None noted |