May 2023Outcomes Among People With Schizophrenia Participating in General-Population Smoking Cessation

Outcomes Among People With Schizophrenia Participating in General-Population Smoking Cessation Treatment: An Observational Study
Résultats chez les personnes souffrant de schizophrénie qui participent à un traitement de désaccoutumance au tabac dans la population générale : une étude par observationScott Veldhuizen, PhD¹

, Anjali Behal, BHSc², Laurie Zawertailo, PhD^1,3,4, Osnat Melamed, MD¹

, Mahavir Agarwal, MBBS, MD, PhD^5,6, and Peter Selby, MBBS, CCFP(AM), FCFP, DFASAM, MHSc^1,2,4,5,7,8

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The Canadian Journal of Psychiatry / La Revue Canadienne de Psychiatrie
2023, Vol. 68(5) 359‐369
© The Author(s) 2023
Article reuse guidelines:
sagepub.com/journals-permissions
DOI: 10.1177/07067437231155693
TheCJP.ca | LaRCP.caimg2
AbstractObjective: People with schizophrenia are much more likely than others to smoke tobacco, raising risks of disease and premature mortality. These individuals are also less likely to quit successfully after treatment, but the few existing clinical and observational studies have been limited by small sample sizes, and have generally considered specialized treatment approaches. In this analysis, we examine outcomes, service use, and potential explanatory variables in a large sample of people with schizophrenia treated in a general-population cessation program.Method: Our sample comprised 3,011 people with schizophrenia and 77,790 controls receiving free nicotine replacement therapy through 400 clinics and health centres. We analysed self-reported 7-day abstinence or reduction at 6-month followup, as well as the number of visits attended and self-reported difficulties in quitting. We adjusted for demographic, socioeconomic, and health variables, and used multiple imputation to address missing data.Results: Abstinence was achieved by 16.2% (95% confidence interval [CI], 14.5% to 17.8%) of people with schizophrenia and 26.4% (95% CI, 26.0% to 26.7%) of others (absolute difference = 10.2%; 95% CI, 8.5% to 11.9%; P < 0.001). After adjustment, this difference was reduced to 7.3% (95% CI, 5.4% to 9.3%; P < 0.001). Reduction in use was reported by 11.8% (95% CI, 10.3% to 13.3%) and 12.5% (95% CI, 12.2% to 12.8%), respectively; this difference was nonsignificant after adjustment. People with schizophrenia attended more clinic visits (incidence rate ratio [IRR] = 1.15, 95% CI = 1.12% to 1.18%, P < 0.001) and reported more difficulties related to “being around other smokers” (odds ratio [OR] = 1.28; 95% CI, 1.11% to 1.47%; P = 0.001).Conclusion: There is abundant demand for tobacco cessation treatment in this population. Outcomes were substantially poorer for people with schizophrenia, and this difference was not explained by covariates. Cessation remained much better than for unaided quit attempts, however, and engagement was high, demonstrating that people with schizophrenia benefit from nonspecialized pharmacological treatment programs.RésuméObjectif : Les personnes souffrant de schizophrénie sont beaucoup plus susceptibles que d’autres de fumer du tabac, ce qui accroît les risques de maladie et de mortalité prématurée. Ces personnes sont aussi moins susceptibles de quitter avec succès après le traitement, mais les quelques études cliniques et par observation existantes ont été limitées par de petites tailles d’échantillon, et ont généralement favorisé des approches de traitement spécialisé. Dans la présente analyse, nous examinons les résultats, l’utilisation des services, et les variables explicatives potentielles dans un vaste échantillon de personnes souffrant de schizophrénie traitées dans un programme de cessation de la population générale.Méthode : Notre échantillon comportait 3,011 personnes souffrant de schizophrénie et 77 790 témoins recevant une thérapie gratuite de remplacement de la nicotine dans 400 cliniques et centres de santé. Nous avons analysé une abstinence ou une réduction de 7 jours auto-déclarée au suivi de six mois, de même que le nombre de visites au traitement et les difficultés auto-déclarées de cesser. Nous avons ajusté pour les variables démographiques, socio-économiques et de santé, et avons utilisé une imputation multiple pour tenir compte des données manquantes.Résultats : L’abstinence a été atteinte par 16,2 % (IC à 95 % = 14,5 % à 17,8 %) des personnes souffrant de schizophrénie et 26,4 % (26,0 %, 26,7 %) des autres (différence absolue = 10,2 %; 8,5 %, 11,9%; P < 0.001). Après ajustement, cette différence était réduite de 7,3 % (5,4 %, 9,3 %; P < 0.001). La réduction de l’usage était déclarée par 11,8 % (10,3 %, 13,3 %) et 12,5 % (12,2 %, 12,8 %), respectivement; cette différence était non significative après ajustement. Les personnes souffrant de schizophrénie ont fait plus de visites à la clinique (IRR = 1,15, IC à 95 % = 1,12, à 1,18, P < 0.001) et déclaré plus de difficultés liées au fait « d’être autour d’autres fumeurs » (RC = 1,28; IC à 95 % = 1,11 à 1,47; P = 0.001).Conclusion : Il y a une demande abondante du traitement pour cesser de fumer dans cette population. Les résultats étaient substantiellement plus mauvais pour les personnes souffrant de schizophrénie, et cet écart n’était pas expliqué par les covariables. Les cessations demeuraient quand même plus réussies que pour les tentatives sans aide, toutefois, et l’engagement était élevé, démontrant que les personnes souffrant de schizophrénie bénéficient de programmes de traitement pharmacologique non spécialisés.Keywordstobacco, nicotine replacement therapy, treatment engagementIntroductionCigarette smoking is highly prevalent among people with schizophrenia. In North America, approximately 62% of schizophrenia patients smoke tobacco, compared to 15% of the population without a psychiatric condition.^1,2 People with schizophrenia also tend to smoke more cigarettes per day and to be more dependent on tobacco.³ Premature mortality among people with schizophrenia is very high, and this is partly due to a heavy burden of tobacco-related disease.^4-8Explanations of the high prevalence of tobacco use in this group include biological, psychosocial, and systemic factors. People with schizophrenia experience dysfunction in neural networks involving dopamine, glutamate, and γ-aminobutyric acid, which may be partially remediated by activation of nicotine acetylcholine receptors during smoking.⁹ Tobacco smoke also expedites the metabolism of antipsychotic medications and people who smoke therefore have a reduced blood concentration of antipsychotic medications. This may reduce antipsychotics’ side effect burden, but also often necessitates an increase in medication doses.¹⁰ Due to illness-related functional difficulties and gaps in educational attainment, people with schizophrenia are also overrepresented among low-wage workers, who have a higher prevalence of tobacco use.¹¹ Many also report that smoking acts as a “social lubricant,” facilitating interpersonal interactions in work and leisure settings; smoking may thus be linked to a sense of belonging and quitting to fear of isolation,^12,13 especially in light of the stigma and marginalization that affect people with schizophrenia.Mental health systems have also long had smokingpermissive cultures, due to the historical use of cigarettes to control inpatients,¹⁴ efforts by the tobacco industry to promote smoking among people with mental illness,¹⁵ misconceptions regarding potential mental health benefits of smoking,¹⁴ and clinicians’ doubts about patients’ ability to quit.¹⁶ Diagnostic overshadowing of tobacco use by what seem to be more pressing mental health concerns may also lead clinicians to assign smoking cessation a lower priority for people with severe mental illness.^13,17 Treatment is also often difficult to afford or access for people with schizophrenia, who often have low incomes and sometimes struggle to obtain stable housing.^18-20 This also means, however, that the financial burden of smoking is often acute for these individuals, and that cessation offers potential additional improvements in quality of life.²⁰A recent meta-analysis of observational studies showed a lower probability of cessation among people with schizophrenia than among either healthy controls (odds ratio [OR] = 0.45) or people with other psychiatric conditions (OR = 0.79).² The authors, however, noted significant publication bias, a small number of included studies, small sample sizes, and a significant association between reported cessation rate and study quality. Difficulties in quitting may be related to more severe symptoms of nicotine withdrawal, which include irritability, loss of focus, anxiety, and impatience.¹³ Given the effects of smoking on the metabolism of antipsychotic medications,¹⁰ increased medication side effects may also occur if smoking is reduced. Finally, the same factors that contribute to the increased prevalence of smoking in this population may also account for some differences in treatment outcome. These include low levels of income, education, and occupational attainment, and high levels of comorbid mental health and substance-related conditions,^18,21-23 all of which have been shown in generalpopulation cohorts to be associated with lower probabilities of successful cessation after treatment.^24,25Evidence supports the use of pharmacological treatments for smoking cessation among people with schizophrenia.^12,26,27 These treatments include the prescription medications varenicline and bupropion, as well as nicotine replacement therapy (NRT), which is generally available over the counter. Varenicline and bupropion have been shown not to cause important neuropsychiatric side effects among people with psychiatric conditions,²⁸ although evidence for people with psychotic conditions specifically is less clear. NRT has a long history of use and a wellestablished safety profile, even if used while continuing to smoke.²⁹ Limited evidence from trials suggests that behavioural therapy and lifestyle changes may be less effective in this population,^12,30 although this question remains somewhat uncertain, due to heterogeneity across studies and the widespread practice of incorporating both psychosocial and pharmacological treatments into interventions, which continues to be the standard of care.³¹In this study, we consider outcomes after NRT-based smoking cessation treatment among people with schizophrenia. NRT alleviates withdrawal symptoms and reduces cravings by replacing nicotine from cigarettes. It is delivered via long-acting transdermal nicotine patches and/or shorteracting forms such as lozenges, gum, inhalers, and nasal sprays.³² NRT does not require a prescription, and can thus be provided by nurses and counsellors in community health centres, addictions agencies, and other contexts. Given the cost, and sometimes scarcity, of physician treatment, this makes it an important option for public health programs, and may be particularly valuable in the case of people with schizophrenia, for whom nonpharmacological interventions have shown unclear effectiveness.In the general population, NRT increases the probability of quitting successfully by 50%, more when the patch is paired with a short-acting form.^32,33 Few clinical trials of NRT have been conducted among people with schizophrenia, and sample sizes have been very small.^34,35 The one larger clinical trial of patients with psychotic disorders (57% with schizophrenia) that exists failed to detect a significant effect on cessation, but reported an effect estimate consistent with that in the general population (OR = 1.72), and observed a significant effect on smoking reduction.Our primary goal in the present analysis was to measure cessation and reduction outcomes among people with schizophrenia and to compare these outcomes to those among other patients. Our secondary goal was to evaluate factors that may account for some differences in outcomes. By using the largest cohort to date of people with schizophrenia treated for smoking cessation, we aimed to measure differences and evaluate potential effect modifiers with greater statistical power than has previously been available.MethodsSample PopulationWe drew data from the Smoking Treatment for Ontario Patients (STOP) program. STOP provides up to 26 weeks of free NRT and behavioural counselling, and operates through approximately 400 partnered clinics, which include team-based primary care (family health teams, community health centres, and nurse practitioner-led practices) and addiction treatment agencies. The STOP program recommends that providers supply both the nicotine patch and one short-acting form, with doses adjusted for the heaviness of smoking and types supplied according to patient preference. Participants are encouraged to set a quit date, but the long treatment period supports the use of NRT before cessation and for reduction goals, as well as for relapse or repeated quit attempts. Most clinicians providing care through the STOP program are nurses, pharmacists, social workers, or counsellors. STOP is funded by the Ontario Ministry of Health, with ethics approval from the Research Ethics Board at the Centre for Addiction and Mental Health (protocol numbers 058-2011 and 154-2012). Neither participants nor participating sites receive financial incentives to participate.STOP enrolls 15,000 to 20,000 people each year, and participants report, on average, lower levels of income and education and a higher prevalence of health conditions than the general population.³⁶ Participants are typically seen every 2 to 4 weeks. At each contact, providers, supply more NRT as needed and collect visit-specific data. Cessation outcomes are assessed through interviews conducted 3, 6, and 12 months after the initial baseline visit. The program uses the 6-month interview as its primary outcome and makes the most intensive efforts to obtain data at this time. Some follow-up assessments are completed during a clinical appointment, but most participants are contacted by email or phone. Given the program size and nature of follow-ups, biochemical confirmation was not feasible. However, the validity of self-reported smoking status has been shown to be good in the general population^37,38 and among people with psychotic disorders.²⁶We included enrolments between April 11, 2016, and November 30, 2021. This start date was chosen because the baseline questionnaire was expanded at this time to include important covariates, while the end date allows for inclusion of all participants who were eligible for a 6-month outcome assessment at the time of analysis. There were 118,014 enrolments within the study period. Of these, we removed 2,288 (1.9%) without signed consent to use the data for research purposes, 620 (0.5%) that had incomplete baseline surveys, 8,556 (7.2%) who were not daily smokers at baseline, 1,038 (0.9%) who had no recorded visits, and 195 (0.2%) who did not report their baseline smoking level. Participants can also reenroll in STOP after one year. In order to ensure that observations were independent, we used probabilistic deduplication to include only the first enrolment for each person. This meant removing a further 19,958 (16.9%) enrolments, leaving an analysis sample of 85,359. We identified people with schizophrenia in the cohort if they reported that they had “ever been diagnosed with” schizophrenia. All others were assigned to the control/comparison group.OutcomesFor our primary outcome, we created a 3-level outcome variable using data from the 6-month (6M) follow-up: selfreported 7-day tobacco abstinence (a response of “no” to the question, “have you smoked a cigarette, even a puff, in the last 7 days?”); reduction (decrease of 50% or more in cigarettes per day or a transition from daily to occasional smoking); and continued smoking (all others). We then examined changes in the measured association between these outcomes and schizophrenia after adjustment for different blocks of covariates. To more fully address our secondary research question, we also examined difficulties experienced during the quit attempt. Participants were asked whether they had experienced any of these difficulties during the 6M follow-up interview. We created one outcome by summing positive responses to items asking about “depression,” “anxiety,” “stress,” and “boredom”; and separately analysed the presence or absence of difficulties related to “being around other smokers.” Finally, to more closely examine differences in service use, we compared the number of clinical visits attended in the 6M following enrolment.AnalysisTo examine the importance of site-level differences in outcomes, we first fit a multilevel model including a random intercept for the clinical site. As the intercept-level variance was small, we used single-level models in our analysis. For our primary outcome (quit vs. reduced vs. continued smoking), we used multinomial logistic regression. In this type of model, coefficients for other levels of the outcome reflect comparisons to the base level and thus depend on the proportion of subjects at that level. We therefore calculated average adjusted predictions—adjusted probabilities of quitting, reducing, and continuing to smoke—for people with and without schizophrenia. As these models yield a coefficient for each level of the outcome, we also used postestimation tests to obtain an overall p-value for the schizophrenia indicator variable.The analysis for our primary outcome had two aims: to measure the association between schizophrenia and outcome independent of potentially important covariates and to gauge the importance of other variables in modifying this association. For the latter purpose, we fit separate models for each of the 6 blocks of variables, as well as unadjusted and fully adjusted models. In Model 1, we included only age and gender. In subsequent models, we included age and gender plus a set of additional variables: (1) smoking history and severity of tobacco dependence (age began daily smoking, cigarettes smoked per day at baseline, time to first cigarette after waking); (2) engagement in treatment and care received (type of organization attended, type of NRT initially prescribed, total clinical visits); (3) motivation and planning (whether a quit date was specified, self-rated importance of quitting and confidence in the ability to quit); (4) health and substance use (body mass index [BMI] category, physical health diagnosis, nonschizophrenia mental health diagnosis); (5) substance-related diagnosis (alcohol or drug dependence), past-month cannabis use; and (6) socioeconomic status (SES; education level, household income, and employment status). Finally, we fit a fulladjusted model including all covariates. We used fractional polynomial models to examine continuous variables for linearity. Based on these results, we used a cubic transformation of patient age and an inverse transformation of the age of initiation. As 89% (2,524 of 2,842 who completed the item) of STOP participants with schizophrenia reported current medication use, and we lacked more detailed data, we did not include this variable in our analysis. We selected covariates a priori based on relevant literature and prior STOP research.Outcome data from the 6M follow-up interview were available for 50,934 (60%) of the participants. This proportion was somewhat lower among people with schizophrenia (n = 1,608, 53%). Our dataset also had sporadic missing data for baseline variables (see Table 1), including the schizophrenia item itself, which was not answered by 4,558 (5.3%) of participants. We retained these patients in our analyses, on grounds that nonresponse to this item may not have been random. To adjust analyses for missingness, we used multiple imputation (MI) with chained equations. We generated 20 imputed datasets. In the imputation process, we included all variables from our substantive models, as well as a set of auxiliary variables associated with our primary outcome: quit status at 3-month (3M) and 12-month (12M) follow-ups (where available), and whether the participant had quit smoking at their last clinical visit before the 6M interview. As with other missing variables, participants who did not respond to the schizophrenia item were randomly classified within each MI dataset based on their calculated probability of having this diagnosis. To understand the possible implications of this decision, we conducted a brief sensitivity analysis by rerunning the fully adjusted model for our primary outcome including only people who responded to the question about schizophrenia diagnosis.Tab1Tab1aTable 1. Descriptive Statistics.^aFor each of our two secondary outcomes, we fit unadjusted and fully adjusted models. For the “quit difficulties” outcome, initial models appeared to violate the proportional odds assumption for ordinal regression. We therefore fit generalized ordinal logistic models using the gologit2 package for Stata. We used logistic regression for the “other smokers” outcome and negative binomial regression for the number of clinical visits attended. We performed all analyses using Stata 16.³⁹ResultsOf our total sample of 85,359, 3,011 (3.5%) self-reported a lifetime diagnosis of schizophrenia, 77,790 (91.1%) did not, and 4,558 (5.3%) did not respond. Including only people with complete data, the prevalence of schizophrenia was 3.7% (95% confidence interval [CI], 3.6% to 3.9%). Descriptive characteristics are shown in Table 1. Compared to controls, people with schizophrenia were more often male, had much lower levels of income, had a higher prevalence of obesity and comorbid mental health and substance use conditions, and were more dependent on tobacco.After MI, but before statistical adjustment, 16.2% (95% CI, 14.5% to 17.8%) of people with schizophrenia reported being abstinent from tobacco at 6M follow-up, and another 10.7% (95% CI, 9.4% to 12.1%) had reduced their use. For other participants, 26.0% (95% CI, 26.0% to 26.7%) were abstinent and 12.6% (95% CI, 12.3% to 12.8%) had reduced their use. The absolute group differences were 10.2% (95% CI, 8.5% to 11.9%; P < 0.001) for cessation and 1.8% for reduction (95% CI, 0.5% to 3.2%; P < 0.001). After the addition of all covariates, predicted group differences in cessation probabilities (Table 2) became 7.3% (95% CI, 5.1% to 9.3%) for cessation and 0.7% (95% CI, −0.9% to 2.2%; nonsignificant) for reduction. Our sensitivity analysis, which included only people who provided their schizophrenia status, changed the coefficients reflecting associations of this variable with cessation and reduction by under 1.5%.Model coefficients are shown in Table 3. In all models, joint group differences across the 3 outcome levels were highly significant (P < 0.001), and people with schizophrenia were less likely than others to quit successfully (all P < 0.001). The model predictions and their CIs, however, do not show clear differences across sets of variables, with the possible exception of the comparison of the baseline model to that including SES variables.Results for our secondary outcomes are shown in Table 4. People with schizophrenia reported more difficulties related to self-reported depression, anxiety, boredom, and stress, but this difference was not significant after adjustment (overall P = 0.14). However, we did find a significant but small difference in difficulties related to “being around other smokers.” People with schizophrenia also attended more clinical visits than other patients, with an average of 3.9 (median = 3, SD = 3.5), compared to 3.5 (median = 2, SD = 2.8) among other participants. After adjustment, this difference remained highly significant (P < 0.001).DiscussionIn this community-based smoking cessation program, patients with schizophrenia were less likely to quit successfully than other participants, but were about equally likely to reduce their smoking. Notably, our reference group consisted of all other program enrollees, and thus included a substantial proportion of people with psychiatric conditions other than schizophrenia. Model results suggest that lower SES and more prevalent comorbid health problems among people with schizophrenia explain a portion of the group difference in outcomes, while their longer engagement in treatment probably reduced it slightly. Differences in self-reported barriers to quit were not substantial, except for a small potential effect of exposure to other smokers.Tab2Table 2. Adjusted Average Predictions by Model for Participants with and Without Schizophrenia.We estimated that 16% of people with schizophrenia were abstinent from smoking at 6M. This proportion is slightly higher than those reported in clinical trials, but is not inconsistent with them. In the recent Smoking Cessation Intervention for Severe Mental Ill Health Trial (SCIMITAR+) trial, personalized interventions were provided, and the biochemically verified quit proportion was 14%; however, only 55% of patients received pharmacological treatments. Importantly, our outcomes are considerably better than those for unaided quit attempts, which are successful approximately 5% of the time.⁴⁰ Consistent with previous work, we also found that people with schizophrenia were only marginally less likely than others to reduce the amount they smoked. Although this is not as desirable as cessation, reduction does have health benefits⁴¹ and including these individuals means that over 25% of this group saw some meaningful improvement in their use of tobacco over a single episode of treatment.Difficulties in quitting smoking in this population have been linked to more severe withdrawal symptoms,¹³ attention,⁴² affect,⁴³ executive function,^42,44 and interactions with antipsychotic drugs.⁹ Circumstances and conditions associated with cessation success in the general population, including comorbid illnesses, substance use, severity of dependence, and lower SES, are also highly prevalent among people with schizophrenia.^18,21-25 Given the number of variables we considered, we did not attempt to test specific causal pathways. However, we were able to adjust for most of the factors above, with the exception of medication use and specific psychiatric symptoms, and our secondary analysis showed that self-reported barriers to cessation were only slightly more common among people with schizophrenia. Although residual confounding cannot be excluded, our results imply that explanations for the remaining disparity in outcomes should probably be sought in issues arising from schizophrenia itself. The reported role of attention, affect, and executive function in prediction cessation within samples of people with psychotic illnesses suggests that psychiatric symptoms might similarly underlie differences between these individuals and others. It is also possible that competing needs, arising, for example, from psychiatric crises or other personal difficulties, might interfere with cessation attempts for some individuals.Tab3Table 3. Relative Risk Ratios (RRRs) for Associations Between Schizophrenia and Smoking Cessation Treatment Outcomes Across Models.Tab4Table 4. Associations Between Schizophrenia and Secondary Outcomes.At 3.7%, the prevalence of schizophrenia among STOP participants is considerably higher than in the general population.⁴⁵ This will be due in part to the association between schizophrenia and smoking,^9,46 and also to the nature of the program, which reaches people with lower levels of SES, as well as those who are in regular contact with the healthcare system. The numbers also demonstrate, however, that there is abundant demand for smoking cessation treatment among people with schizophrenia.Although people with schizophrenia are less likely than others to receive adequate care for physical health conditions,^47,48 STOP participants with schizophrenia attended slightly more clinical visits than others, and this difference was not accounted for by any of the covariates we considered. This may be because their quit attempts are protracted, or because they continue to use NRT for longer than other participants after quitting. It is also possible, however, that this is an advantage of integrated treatment. Participating STOP clinics also provide other forms of treatment or support, and people can thus access NRT and counselling in the same place they receive other care. In any case, this result shows that people with schizophrenia are able and willing to engage successfully in this form of care. Combined with the high prevalence of schizophrenia in our program, this speaks to the desire of many of these individuals to quit and contradicts any beliefs that may remain about the secondary importance of physical and preventive healthcare in this population. It is possible that integrating smoking cessation treatment into specialized psychiatric care would provide further benefits. However, our results demonstrate that many people with schizophrenia benefit from enrolment in nonspecialized, low-cost treatment programs.Strengths and LimitationsDue to the nature of observational data, we are unable to identify clear causal associations. Our data also do not include detailed information on medication use and rely on self-reports both for the diagnosis of schizophrenia and for smoking cessation outcomes. Data on income, employment, and other variables tend to support the validity of data on diagnosis, and, given the stigma attached to it, we believe that false-positive self-reports will have been uncommon. Biochemical confirmation of smoking status was also not practical, given the STOP program’s size and the nature of the follow-ups. As we have noted, however, self-reported cessation outcomes agree well with biochemically verified smoking status in this population. We were also able to adjust only fairly crudely for some variables, notably substance-related problems, and it is possible that more detailed measures would make it possible to better understand outcome differences.Although the follow-up rate in STOP is equal to or better than those of any observational datasets of comparable size,^49,50 our results are also limited by missing outcomes. Our use of MI should have mitigated any resulting biases, but this approach is entirely accurate only when missingness is a function of observed values (i.e., when data are “missing at random”), which is not a verifiable assumption. An important strength of this study, however, is that we were able to analyse a very large sample of people with schizophrenia, which provided the statistical power to constrain effects and explore potential explanatory variables. Finally, the realworld nature of the data also means that results should be broadly generalizable.ConclusionOur results confirm that outcomes following NRT-based smoking cessation treatment are poorer among people with schizophrenia, and suggest that this is not due to differences in treatment, SES, or other health variables. However, cessation and reduction remain far more common than in unaided quit attempts, and the high levels of participation and engagement show that many people with schizophrenia are committed to smoking cessation and can successfully engage with, and benefit from, NRT-based smoking cessation programs targeted at the general population—an approach that is advantageous because of its wide reach and low cost, relative to specialized mental health care.Data AccessSTOP data include sensitive personal and medical information, and cannot be made publicly available. Access to deidentified data can be arranged on reasonable request by contacting the primary author.Declaration of Conflicting InterestsThe author(s) have no conflict of interest to declare. However, Peter Selby has the following general disclosures to report: grants and/or salary and/or research support from the Centre for Addiction and Mental Health, Health Canada, Ontario Ministry of Health and Long-term Care, Canadian Institutes of Health Research, Canadian Centre on Substance Use and Addiction, Public Health Agency of Canada, Ontario Lung Association, Medical Psychiatry Alliance, Extensions for Community Healthcare Outcomes, Canadian Cancer Society Research Institute, Cancer Care Ontario, Ontario Institute for Cancer Research, Ontario Brain Institute, McLaughlin Centre, Academic Health Sciences Centre, Workplace Safety and Insurance Board, National Institutes of Health, and the Association of Faculties of Medicine of Canada. PS also reports receiving funding and/or honoraria from the following commercial organizations: Pfizer Inc., Canada, Shoppers Drug Mart, Bhasin Consulting Fund Inc., Patient-Centered Outcomes Research Institute, ABBVie, and Bristol-Myers Squibb. Further, PS reports receiving consulting fees from Pfizer Inc., Canada, Evidera Inc., Johnson & Johnson Group of Companies, Medcan Clinic, Inflexxion Inc., V-CC Systems Inc., MedPlan Communications, Kataka Medical Communications, Miller Medical Communications, Nvision Insight Group, and Sun Life Financial. Through an open tender process Johnson & Johnson, Novartis, and Pfizer Inc. are vendors of record for providing smoking cessation pharmacotherapy, free or discounted, for research studies in which PS is the principal investigator or coinvestigator.FundingThe author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Ontario Ministry of Health and Long-Term Care (grant number HLTC5047FL).ORCID iDsScott Veldhuizen

https://orcid.org/0000-0003-3969-2756
Osnat Melamed

https://orcid.org/0000-0002-9663-2226
Peter Selby

https://orcid.org/0000-0001-5401-2996
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¹ Nicotine Dependence Services, Centre for Addiction and Mental Health, Toronto, Canada² Dalla Lana School of Public Health, University of Toronto, Toronto, Canada³ Department of Pharmacology and Toxicology, University of Toronto, Toronto, Canada⁴ Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Canada⁵ Department of Psychiatry, University of Toronto, Toronto, Canada⁶ Schizophrenia Division, Centre for Addiction and Mental Health, Toronto, Canada⁷ Department of Family and Community Medicine, University of Toronto, Toronto, Canada⁸ Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, CanadaCorresponding author:Scott Veldhuizen, PhD, Nicotine Dependence Services, Centre for Addiction and Mental Health, Toronto, Canada. Email: scott.r.veldhuizen@gmail.comJournal CoverOtsuka Lundbeck AdEditorial BoardBluewater Health AdEisai Dayvigo AdJournal infoThe University of British Columbia AdSAGE JournalsSAGE Peer Reviewer RewardsSystematic Review: Canadian Network for Mood and Anxiety Treatments (CANMAT) Task Force ReportCommentary: Underfunding of Innovative Mental Health Research: A Call for ActionOriginal Research: Feasibility, Acceptabiity, and Safety of Faecal Microbiota TransplantationOriginal Research: Cross-sectional Study of Factors Associated With Suicide Ideation in OntarioOriginal Research: Mental Disorders Among Mothers of Children Born Preterm: A Population-BasedOriginal Research: Neuropsychiatric Symptom Burden across Neurodegenerative DisordersOutcomes Among People With Schizophrenia Participating in General-Population Smoking CessationLetter to the Editor: Evidence-based Treatment for Stimulant Use Disorder: Time to Hit the CommunityPosition Paper: Collaborative Mental Health Care in Canada: Challenges, Opportunitiesénoncé de Principe: Les soins de santé mentale en collaboration au Canada: Défis, possibilitésSAGE VideoExplore and discover more from SAGECPA's 2023 Annual Conference Save the DateThank You to CPA Members