People with schizophrenia are 2-3 times more likely to smoke tobacco than the rest of the population, so helping them quit is a significant public health issue.
The evidence for smoking cessation interventions in the general population is fairly well defined. We know quite a bit about what works and we have a range of options to offer to anyone seeking help in kicking the habit. However, many of these treatments haven’t been well tested in people with schizophrenia and there’s some concern that they may have side-effects specific to people with psychosis.
The Cochrane Tobacco Addiction Group have recently updated their review on this subject, which includes a number of new trials that add further weight to the overall findings. It’s by no means a conclusive review, but it does provide evidence about the effectiveness of bupropion, varenicline, contingent reinforcement, nicotine replacement therapy and other psychosocial interventions.
Methods
People with schizophrenia who smoke heavily are almost 3 times more likely to die from cardiac disease compared with non-smokers with schizophrenia
The reviewers conducted a gold standard search and found 34 randomised controlled trials to include in their analysis.
Study participants were adult smokers with a current diagnosis of schizophrenia or schizoaffective disorder. People with substance misuse issues were not excluded as service users with schizophrenia often use other substances.
Drug treatments and non-drug treatments were included and the primary outcome was smoking abstinence at 6 months.
The adverse effects of the treatments were carefully measured.
Two reviewers independently assessed the eligibility and quality of trials, as well as extracted data. Data was pooled using the random-effects model.
Results
- A meta-analysis of RCTs found that buproprion had significantly better cessation rates compared with placebo:
- At the end of treatment (7 trials, N = 340; risk ratio [RR] 3.03; 95% confidence interval [CI] 1.69 to 5.42; NNT = 7)
- After 6 months (5 trials, N = 214, RR 2.78; 95% CI 1.02 to 7.58; NNT = 15)
- No major side-effects were reported with bupropion and there were no significant differences in psychiatric symptoms between the bupropion and placebo groups
- Fewer trials looked at varenicline, but 2 studies did show significantly higher cessation rates compared with placebo:
- At the end of treatment (2 trials, N = 137; RR 4.74, 95% CI 1.34 to 16.71)
- Although at 6 months this was not sustained (1 trial, N = 128, RR 5.06, 95% CI 0.67 to 38.24) [Note the confidence interval of less than 1.0]
- Psychiatric symptoms were similar in the varenicline and placebo arms, but some serious side effects (suicidal ideation and behaviours) were reported in 2 patients on varenicline
Conclusions
The reviewers concluded:
Bupropion increases smoking abstinence rates in smokers with schizophrenia, without jeopardizing their mental state
Bupropion increases smoking abstinence rates in smokers with schizophrenia, without jeopardizing their mental state. Varenicline may also improve smoking cessation rates in schizophrenia, but its possible psychiatric adverse effects cannot be ruled out. Contingent reinforcement may help this group of patients to quit and reduce smoking in the short term. We failed to find convincing evidence that other interventions have a beneficial effect on smoking in schizophrenia.
Epidemiological studies have shown that people with schizophrenia who smoke heavily (≥1 pack a day) are almost 3 times more likely to die from cardiac disease compared with non-smokers with schizophrenia. Hopefully this evidence can help some of these individuals become less dependent on tobacco.
It’s important to stress that many of the other treatments included in this review were not found to be ineffective, but there simply wasn’t enough evidence to prove their safety and efficacy.
Link
Tsoi DT, Porwal M, Webster AC. Interventions for smoking cessation and reduction in individuals with schizophrenia. Cochrane Database of Systematic Reviews 2013, Issue 2. Art. No.: CD007253. DOI: 10.1002/14651858.CD007253.pub3.
I’m always interested in seeing buproprion mentioned in relation to smoking cessation. Many years ago, when I worked in clinical audit, a GP wanted an audit doing around the use of buproprion. He was confused as the trials said it was great while his experience was that it didn’t do much good. It was a powerful lesson for me that demonstrated that trial results and coal-face reality are not the same.
Hi Jon,
Thanks for posting your comment. Please could you elaborate a bit? I’m not quite sure what you’re getting at.
Are you saying that we shouldn’t use the findings of this well conducted systematic review to inform the services we provide for people with schizophrenia who are trying to stop smoking?
Are the trials included in this review very different from the coal-face reality you speak of?
I expect that you would get a wide range of experiences and opinions if you asked a number of GPs, doctors, nurses, carers and service users about the best way to give up smoking. It is after all a very subjective thing to do.
What sort of evidence do you think we should use to help inform our decisions for questions such as this?
Cheers,
André
An important part of practicing evidence-based healthcare is the generalizability of the research you’re looking at (alongside issues such as quality). Often clinical research is conducted in a sterile way which is not the same as the reality of clinical practice. For instance, many trials have quite explicit exclusion criteria. So, a trial might exclude co-morbidities, people over (or under) a certain age-range, particularly genders (women are often overlooked in trials). So, the result of the clinical trial is restricted to those that are included.
Unfortunately, in applying the research, the clinician has to struggle with the application of it, as the person sitting in front of them does not neatly fit into the research inclusion criteria (so, they might be an elderly woman with numerous co-morbidities). Does the intervention work then?
So, I think systematic reviews have an important role – they can tell us the average effectiveness of an intervention across a broad population (albeit a strictly defined – by inclusion/exclusion criteria – population). But they are not the complete picture.
Is the anecdote of the GP meaningless? Perhaps in isolation, but what if 50% of the GPs said the same thing – is that still meaningless? I personally believe that post-trial evaluation ‘in the wild’ are important. Alas, people say the potential for bias is too high and therefore move on – which is a shame.
Taking it back to the SR you highlighted. If I was an elderly woman, with multiple co-morbidities I’d be keen to see the usefulness of buproprion in people like myself. Yes, it’d be potentially biased but – if the systematic review didn’t cover people like me – that would be a bias. Let me see both sort of results and let me be an informed patient better able to make a decision for myself.
Bupropion is best treatment to help people with #schizophrenia give up smoking according to @cochranecollab http://t.co/HRvyiZAAwM
I’ve long been interested in the possibility that nicotine is to an extent therapeutic in schizophrenia. With e-cigarettes becoming more popular, would it not be better to just shift people from tobacco to this -hopefully harmless- alternative. Moving to e-cigarettes might even be healthier than quitting.