Tobacco smoking is among the most significant predictors of cardiovascular disease [1-6] and lung cancer [7-12] in People Living with HIV (PLHIV). In fact, in the antiretroviral era, smoking may contribute to a greater loss of life in PLHIV than HIV itself [9, 13]. In a Danish cohort of PLHIV, 12.3 (95%CI, 8.1-16.4) life years were lost in association with smoking compared to only 5.1 (95%CI, 1.6-8.5) life years lost in association with HIV [9]. In addition, smoking rates are high in PLHIV, with studies reporting 21-84% of individuals being current smokers (vs. 19% in the general population) and 9-30% being former smokers [14-21]. In PLHIV, higher rates of un-employment, substance abuse, low education, lone-liness, depression, and food insecurity have all been associated with smoking or not being ready to quit [2, 22-24].

Smoking is a major modifiable health risk factor that, if addressed effectively, could drastically improve the health of PLHIV. Smokers living with HIV who abstain from tobacco smoking for more than a year are at lower risk of acquiring AIDS-defining illnesses, cardiovascular events, non-AIDS-defining malignancies, and bacterial pneumonia [12, 25-27]. We described the tobacco-related clinical and sociod-emographic characteristics of a convenience sample of tobacco smokers at the Chronic Viral Illness Service (CVIS), a tertiary HIV clinic in Montreal. We conducted an exploratory analysis of smoking cessation methods to identify potential areas of improvement in the clinic’s approach to smoking cessation.

The CVIS follows approximately 2,000 PLHIV and provides multi-disciplinary care for adult patients with chronic illnesses such as HIV and HCV. The clinic is located within the McGill University Health Centre (MUHC), a large public tertiary care hospital. Inclusion criteria for this study were patients with 1) HIV infection; 2) self-reported current tobacco smoking; 3) appoint-ments at the CVIS for clinical care; and 4) the ability to read and understand French or English. Self-reported non-smokers or former smokers were excluded from this study. This study was approved by the MUHC Research Ethics Board.

A total of 72 PLHIV participated in this study. The characteristics of the sample are summarized in Table 1. Most participants were men (83.3%) and/or HIV mono-infected (59.7%). The most common HIV transmission risk categories were Men who have Sex with Men (MSM) (40.3%) and People Who Inject Drugs (PWID) (38.9%).

A summary of questionnaire responses is provided in Table 2. Half of the participants (51.4%) were followed by an allied health professional, such as a social worker or psychologist. Participants smoked a median of 330 cigarettes (or about 13 packs) per month and started smoking at a median age of 20 years. About half of the participants (47.3%) reported having their first cigarette of the day within the first 30 minutes of waking. Smoking to reduce stress appeared to be the most common reason for smoking (56.9%), followed by smoking for pleasure (51.4%) and smoking to reduce anxiety (45.8%). Two-thirds of participants (67.6%) reported that they would like to quit within the next six months and a similar number (65.3%) indicated they were interested in a clinical trial on smoking cessation. About half of the participants (55.6%) had smoked marijuana in the previous six months.

The results of each McNemar’s test are summarized in Table 3. Among the 63 participants who had ever made a quit attempt (87.5%), both oral therapy (e.g. varenicline or bupropion) (16.7%) and smoking cessation counseling (5.6%) were used less than either nicotine patches (50.0%) or ‘other’ methods (50.0%), which included abstinence and/or nicotine gum.

The current study describes the smoking experience in a clinical sample of PLHIV and highlights some potential shortcomings in the CVIS’s strategy to smoking cessation.

Although two-thirds of the participants in our sample expressed an interest in quitting within six months, access to the majority of effective smoking cessation methods was relatively low. Half of the study participants (50.0%) had ever used nicotine patches to quit smoking, making Nicotine Replacement Therapy (NRT) the most frequently used smoking cessation aid. While this finding indicates that NRT is accessible to many participants, it could also suggest that NRT may not be optimally prescribed or administered to this group. Studies in PLHIV have found that compliance with NRT tends to be poor [29-32].

Counselling and oral therapy were underutilized evidence-based smoking cessation strategies in our sample. Only 12 (16.7%) participants had ever tried oral therapy to quit smoking and only 4 (5.6%) had ever received counselling to quit smoking. In the general population, bupropion nearly doubles the odds of abstinence at 12 months compared to placebo (OR 1.85, 95% CI 1.63-2.10) and varenicline nearly triples the odds (OR 2.89, 95% CI 2.40-3.48), whereby the abstinence rate of control participants is about 10% [33]. Few Randomized Controlled Trials (RCTs) have been conducted in PLHIV, but these treatments appear to be efficacious and well-tolerated [29]. Similarly, a recent RCT of 248 PLHIV in France found that quit rates with varenicline were higher than the standard of care alone (OR 2.5, 95% CI: 1.0 to 6.1) [34].

Smoking cessation counselling is another effective intervention used in the general population, with increased relative quit rates of 1.39 (95%CI: 1.24 to 1.57) and 1.98 (95%CI: 1.60 to 2.46) for individual and group counselling, respectively [33]. Studies of smoking cessation counseling in PLHIV have been hindered by methodological issues such as small sample sizes or lack of randomization [29]. However, they appear to demonstrate a positive, albeit modest, effect [29]. In clinics with a multi-disciplinary model of HIV care, such as the CVIS, there is potential for smoking cessation counselling to be delivered along side other types of counselling, in conjunction with optimally dosed NRT or oral therapy. Indeed, combined counselling and phar-macological smoking cessation interventions are effective in PLHIV, with quit rates ranging from 11.8 to 28% [35]. In RCTs involving the general population, quit rates at three to six months ranged from 10% to 36.8% for counselling plus pharmacotherapy compared to 3.3 to 10.3% for phar-macotherapy alone [35]. Early evidence suggests that these rates could be further improved if paired with concurrent treatment for depressive symptoms, which are highly prevalent in our sample [35, 36]. For example, in a recent RCT of PLHIV, combined NRT and cognitive behavioural therapy for smoking cessation and dep-ression/anxiety resulted in a 46% quit rate at six months, significantly higher than the 5% quit rate for NRT alone [36].

Our study had several limitations. Firstly, we were only able to recruit a limited number of participants, which hindered our ability to conduct more in-depth analyses. Secondly, given time and financial constraints, patients were recruited by convenience sampling, with many coming from the Canadian Coinfection Cohort and from the clinic outreach nurse [37]. Thus, our sample is dissimilar from the general pool of HIV positive patients and likely a non-representative subset of smokers at the CVIS, consisting of more HCV-seropositive persons and more individuals followed by an allied health professional who may have more social or psychological needs than the overall pool of smokers in our clinic. This is supported by the descriptive statistics of CVIS patients provided in Table 1. Notably, 39% of our sample was PWID and 40.3% were HCV co-infected, while only 7% and 11.1% of CVIS patients with visits during the study period were PWID or HCV co-infected, respectively. There is currently no systematic identification of tobacco smoking patients at the clinic, which hinders our ability to assess the comparability of our sample with the general pool of tobacco smokers. This may limit the generalizability of our findings. We also did not collect any information about educational or financial char-acteristics of participants, pain, healthcare provider attitudes and/or practices, or timing of smoking cessation interventions, all of which are important factors for smoking cessation [2, 33, 38-43].

Our findings suggest the need for further research to determine and address barriers to smoking cessation and access to effective smoking cessation aids in PLHIV. Future studies might consider factors that affect moti-vation to quit, such as co-morbid mental health and substance use disorders, or the attitudes of HIV health-care providers.