Summary of Results
Using a controlled clinical trial design, the study sought to determine the efficacy of a group tobacco cessation behavioural intervention among tobacco using patients with concomitant mental illnesses in Kenya on tobacco cessation at 24-week follow-up, and to evaluate the effect of a group tobacco cessation behavioural intervention on HRQOL of patients with mental illnesses.
The main study findings include: 1) participants allocated to the intervention group reported a higher cessation rate and lower number of cigarettes smoked or kuber chewed compared with the control group over the study period; 2) adjusted results showed that participants in the intervention group at any point during the study period were almost 14 times more likely to reduce smoking than participants in the control group, though there were a small number of events driving this finding; and 3) intervention group participants reported greater change in HRQOL scores compared with control group participants, though these results were not statistically significant.
Explanation of Results
There were a greater number of participants in the intervention group who achieved the primary outcome, which was statistically significant at the end of week 12, but was not statistically significant by the end of the study at 24-weeks. The results could be considered potentially clinically meaningful given the harmful health effects of even light smoking; however, because the study is underpowered to detect true differences we report these results within this limitation. Similar to our findings, a study by Prochaska et al. (2014) evaluated the effects of a motivational tobacco cessation treatment combined with nicotine replacement therapy compared to usual care initiated in inpatient psychiatry. The study showed that abstinence was significantly higher for the intervention group than usual care at 3-months (13.9% vs 3.2%) and 6-months (14.4% vs 6.5%) at 7-day point prevalence biochemically verified . Due to the high loss to follow-up in this study, strategies to promote retention among study participants are key to better evaluate the intervention’s effectiveness.
The study shows frequent quit attempts and reduced numbers of cigarettes smoked during each meeting. Participants were not told to stop tobacco use immediately as the study did not offer nicotine replacement therapy. Gradual smoking reduction can decrease the severity of withdrawal and cravings compared with immediate cessation. Indeed, withdrawal symptoms and cravings are the main deterents to achieving cessation and contributing to relapse , and has been shown to predict future abstinence in the schizophrenia population . In cessation attempts, cutting down the number of daily cigarettes smoked may increase quit attempts, while encouraging continued attempts and potentially increasing self confidence and success. A higher confidence in ones cessation efforts are thought to increase the likelihood that a final goal – in this case cessation – will be achieved . Successful smoking cessation is difficult, with as few as 3–5% successfully quit without assistance, and less than 10% of all smokers who achieve long term abstinence, succeed after many unsuccessful quit attempts .
Most participants were unable to sustain cessation at the end of the 24-week follow-up period. However, some participants were able to reduce the number of sticks they smoked (< 2 sticks per day) with a higher rate in the intervention group. It may be possible that a longer period or more frequent doses of the group behavioural intervention may have been needed to achieve a higher cessation rate in these participants. This potential value of longer duration of follow-up or more intensive weekly sessions was supported by participants who requested continuity of the follow up, but this was not feasible.
Comparison with Clinical Guidelines and Prior Research
Clinical guidelines for tobacco cessation reported by Fiore et al. (2008) recommend more intensive interventions as well as pharmacotherapy to improve cessation outcomes . The findings of this study suggest that counselling is feasible and potentially effective. Policies to improve availability, accessibility, and affordability of tobacco cessation pharmacotherapy are needed to help Kenyan tobacco users with mental illness quit. Aveyard and Linson-Hawley (2014), noted that people who are reducing their tobacco consumption are more likely to attempt to quit and to succeed than are those who are not. These authors identified a need to teach people methods to help them reduce tobacco consumption as a strategy to increase the likelihood of achieving successful cessation .
Results from de Leon et al. (2005) showed that maintaining tobacco cessation among patients with concomitant mental illness is very difficult. The study, which focused on alcohol, drugs, and smoking cessation, found that almost half (45%) of people with severe psychiatric illness were able to quit alcohol or drugs, but only 10% successfully remained quit in a period of one year. This outcome was similar to our study, as 15% were able to successfully quit at the end of 12 weeks, but only 9% remained successfully quit at the end of the 24-week study period. People with mental illness mostly have poor outcomes with cessation treatments; there is need to develop new interventions specifically focused to this population .
The SCIMITAR study, which was a tobacco cessation intervention incorporating behavioural support and pharmacological aid among persons with mental illness, showed the proportion of participants who quit at 6-months was significantly higher in the intervention group than the control group (14% vs 6%, P = 0.01). Despite our study not offering pharmacological support, it offered the ”cut-down” to quit approach similar to the SCIMITAR trial. The SCIMITAR investigators observed an improvement in physical health in the intervention group at 6-months; however, this difference was no longer evident at 12 months. On the other hand, there was no difference in mental health domains among SCIMITAR participants at six and 12 months .
Results from eight clinical trials with treatment periods lasting eight to 12 weeks started in inpatient settings and continued post discharge, have shown smoking quit rates of different cessation intervention, including behavioural and pharmacological interventions, range from 4–22% among people with mental illnesses . Banham et al. (2010) reviewed eight randomised controlled trials and found similar results to the current study. They found that none of the trials reviewed reported any significant differences between intervention and control groups at the end of follow-up; however, these randomized controlled trials (RCTs) all incorporated nicotine replacement therapy in their interventions. No significant differences was reported between a specialised severe mental illness smoking programme with NRT compared with standard smoking cessation group therapy with NRT at either end of trial or end of follow-up (one RCT). The review reported greater abstinent rates at trial end for: individual therapy together with NRT compared with usual care (RR 2.74, 95% CI 1.10 to 6.81; one RCT); bupropion together with group therapy compared with placebo with group therapy (RR 4.18, 95% CI 1.30 to 13.42; three RCTs); bupropion together with group therapy and nicotine replacement therapy compared with placebo; and group therapy and NRT (RR 2.34, 95% CI 1.12 to 4.91; two RCTs) .
Most of these RCTs had findings almost similar to our study even though most of them incorporated cessation pharmacotherapies. This shows that our study has promise of increased positive outcome, particularly if pharmacotherapies are included.
Strengths and Limitations
This study has several strengths. First, the study was conducted among a high-burden population in a novel setting and was implemented in participants’ usual environments and during regularly scheduled outpatient clinic follow-up days. Second, the study focused on strategies that were readily available and did not have significant direct costs for participants in terms of attending group therapy. Third, the study demonstrated feasibility, acceptability, and a signal of benefit from the intervention suggesting potential benefits with further refinement.
The current study also had important limitations which may influence the certainty of the findings. First, participants self-reported their quit attempts and reduction in amount smoked during every group meeting. Systematic reviews have indicated that self-reports of smoking status are generally accurate unless the participants fear loss of particular benefits if they do not quit . To reduce the risk of ascertainment bias, biochemical verification was conducted on participants who reported complete cessation.
Second, by design, the intervention group met more frequently compared to the control group. Participants may have benefited from the study intervention but may have also been susceptible to the Hawthorne effect, wherein their behaviour changed because of the process of observing the behaviour . In the study, we sought to minimize the effect of this by integrating into usual clinical practice days. We also held intervention sessions on different days than the control groups’ clinical practice days, which reduced the risk of contamination. It is arguable but seems unlikely that control participants might have been motivated to quit tobacco if they perceived that the intervention group was receiving special treatment.
Third, the study had a high loss to follow-up rate, and we treated all participants who were lost to follow up as smokers in the intention to treat analysis. This conservative approach is the typical method of handling missing data in smoking cessation trials . The research team tried to contact all participants who were missing before group meetings began. When a participant failed to attend meetings three consecutive times, they were counted as dropped out (lost to follow-up). Higher retention may have led to a larger effect than was observed, though it may be possible that the opposite effect is also true. Fourth, the study did not analyse the actual cost of the intervention. Knowing the actual cost might help with implementation and replication in different mental health care facilities.