Evaluating the use and perceptions of cannabis and vaping post-cannabis legalisation in people with cystic fibrosis and CFTR-related disorder: survey results from a large Canadian adult cystic fibrosis clinic.

Abstract

Background

This study characterised the use and perceptions of cannabis and vaping in people with cystic fibrosis (CF) and CF transmembrane conductance regulator (CFTR)-related disorder followed by a large Canadian adult CF clinic. It also aimed to assess whether cannabis legalisation in Canada affected perceived benefits and harms, and whether media attention regarding e-cigarette or vaping product use-associated lung injury (EVALI) affected perceptions of vaping.

Methods

An electronic questionnaire was emailed to all clinic patients on 23 April 2021, and remained open until 28 October 2021.

Results

110 individuals completed the questionnaire, of whom 43% identified as a current user of cannabis. As a result of legalisation, 14% of respondents reported change in their perceptions of cannabis, primarily related to decreased stigma and increased awareness of medical indications and potential side effects. Cannabis was reported as being used medically for 85% of current users, with stress, insomnia/lack of sleep, and anxiety being the most common symptoms treated; the majority reported it to be somewhat or very effective to manage symptoms. Overall, 33% of respondents had tried vaping, but only 7% considered themselves current vapers. For 45% of respondents, the 2019 EVALI epidemic was reported to have changed perceptions of potential short-term and long-term effects associated with vaping, with increased awareness of potential harms.

Conclusions

Cannabis use was common, with a reported increase since its legalisation in this population. EVALI media attention was reported to increase awareness for potential harms associated with vaping. CF healthcare providers are well positioned to provide education and support so patients can make informed decisions about cannabis use and vaping.

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Keywords: Cystic Fibrosis

Article notes

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Received 2024 Jul 13; Accepted 2025 Nov 22; Collection date 2025.

Author notes

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WHAT IS ALREADY KNOWN ON THIS TOPIC

Use and perceptions of cannabis products and vaping in people with cystic fibrosis (pwCF) or CF transmembrane conductance regulator (CFTR)-related disorder is not well characterised in the literature.

WHAT THIS STUDY ADDS

We surveyed pwCF and people with CFTR-related disorder about use and perceptions of cannabis products and vaping; 43% of respondents were current users of cannabis and 7% were current vapers.
Legalisation of cannabis in Canada affected perceptions of safety and effectiveness, while media attention to the e-cigarette or vaping product use-associated lung injury (EVALI) epidemic increased awareness of vaping-associated harms.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

Cannabis products are commonly used by pwCF or people with CFTR-related disorder for symptom management.
CF healthcare providers play an important role in routinely assessing cannabis use and vaping, and providing education and support as needed for harm-reduction strategies.

Introduction

In October 2018, the Canadian government enacted the Cannabis Act, legalising cannabis (marijuana) nationwide;¹ before this, cannabis could only be used in Canada for specific medical indications such as chronic pain, nausea, poor appetite, insomnia, or anxiety.^{2 3} As people with cystic fibrosis (pwCF) are commonly affected by these symptoms, cannabis may be perceived by pwCF as an appealing alternative or complement to other treatments.

Cannabis has been associated with several adverse effects, including cognitive dysfunction, impaired driving, anxiety, paranoia, physiological and psychological dependence, and gastrointestinal-related effects such as cannabis hyperemesis syndrome, particularly with tetrahydrocannabinol (THC)-predominant formulations.^{3 4} Of primary concern in pwCF is the potential for inhaled forms of cannabis to worsen respiratory symptoms, directly harm the respiratory tract, and increase risk for airway infection.⁴,⁷ Vaping has become increasingly popular for cannabis administration and is often perceived by cannabis users as less harmful than smoking cannabis.⁸ However, reported lung damage and mortality secondary to e-cigarette or vaping product use-associated lung injury (EVALI) add to mounting evidence that vaping is not as ‘safe’ as initially perceived and marketed to be.⁹,¹¹

Use of cannabis in pwCF is not well characterised. Reported cannabis use in pwCF for recreational and/or medical purposes has ranged from 3% to 31%.¹²,¹⁹ In a study performed at our clinic prior to cannabis legalisation, 25% of 76 survey respondents reported medical use of marijuana; most reported significant improvement in treated symptoms (eg, appetite, pain, sleep) and quality of life was improved overall.¹⁴

In pwCF or people with CF transmembrane conductance regulator (CFTR)-related disorder, the impact of cannabis legalisation on cannabis use or perceived potential benefits and harms of cannabis has not been evaluated, nor has the impact of the 2019 media coverage of EVALI on the perceived safety of vaping. The purpose of this study was to address these questions.

Methodology

A survey-based observational study was conducted. An electronic questionnaire was built on Qualtrics, with some questions adapted from relevant studies.²⁰,²² The final questionnaire contained 46 questions, comprised of multiple choice, unipolar scale, and free-text responses; skip logic was used for select questions (online supplemental appendix table 1).

Patient and public involvement

Patients were not involved in the development of the study research questions, study design or outcome measures. However, the questionnaire was piloted by the clinic’s Patient Advisory Council (PAC). Feedback from the PAC was collated and provided to the study team; this feedback and further discussion with the liaising PAC member guided questionnaire revisions to improve quality and clarity.

Participants

All patients followed by the Adult CF Clinic at St. Paul’s Hospital in Vancouver, British Columbia (BC) were eligible to participate in the study; the clinic population is comprised of pwCF or people with CFTR-related disorder aged 18 years or older. There were no exclusion criteria.

The questionnaire was emailed to all clinic patients on 23 April 2021, with four reminder emails sent at regular intervals before closing on 28 October 2021. The questionnaire cover page indicated that responses were anonymous and questionnaire completion implied consent for inclusion of responses in analyses. The cover page and email invitation both requested that participants not complete the survey more than once, given that it would impact the quality of the study results. The clinic cared for 300 adults with CF or CFTR-related disorder on 23 April 2021 when the survey opened; the exact number of patients who subsequently transitioned care to our CF clinic and received an email invitation to participate during the survey distribution window was not captured.

Analyses

Collected data were analysed with descriptive statistics. All analyses were performed using R Statistical Software (R V.4.0.3) and RStudio (V2.024.9.1.394).^{23 24} Categorical variables were summarised as frequencies and percentages. Exploratory analyses were performed to compare perceptions between different respondent categories (eg, cannabis ‘current user’ vs all other respondents; user of inhaled vs non-inhaled cannabis formulations; reported lung function); the Fisher’s exact test was ultimately used for these analyses, as it is preferred over the χ² test when there are cells with n<5. A value of p<0.05 was considered statistically significant for all analyses.

In this study, an ‘ever-user’ of cannabis or vaping was defined as having tried cannabis or vaping, respectively, at least once, while a ‘never-user’ was defined as having never tried. A ‘current user’ of cannabis was defined as using cannabis on a regular or relatively regular basis and/or an ongoing as-needed basis, and ‘current vaper’ was defined as vaping on a regular or relatively regular basis. A ‘past user’ of cannabis or vaping was defined as an ‘ever-user’ who did not identify as a ‘current user’ or ‘current vaper’, respectively. In the analyses of perceptions of cannabis, ‘non-user’ comprised ‘past users’ and ‘never-users’. ‘Recreational use’ of cannabis was defined as using it for the euphoric effects or ‘high’, while ‘medical use’ was defined as using cannabis for symptom management. Whether or not ‘medical use’ of cannabis was recommended by a healthcare provider and/or via prescription was not asked in the questionnaire.

Results

Of 123 survey responses submitted, 110 were included in analyses and 13 incomplete responses were excluded. This represented 37% of the approximately 300 patients followed by the clinic during the survey distribution window. Baseline demographics and characteristics are outlined in table 1. The study population had a seemingly similar age demographic to the overall CF Clinic population in 2021 (registry data not shown); the mean age of the overall clinic population at that time was 38 years, with 33% between 30 years and 41 years. Unlike the CF clinic population, of which the majority (59%) was male, there was a similar proportion of male (48%) and female (51%) respondents to the survey.

Table 1Reported baseline characteristics

	All respondents (n=110)	Cannabis			Vaping
	All respondents (n=110)	Current users (n=47)	Past users (n=32)	Never users (n=31)	Current users (n=8)	Past users (n=28)	Never users (n=74)
Age (years), n (%)
18–24	18 (16)	13 (28)	1 (3)	4 (13)	4 (50)	6 (18)	8 (18)
25–30	14 (13)	10 (21)	0 (0)	4 (13)	1 (13)	4 (14)	9 (14)
31–40	31 (28)	14 (30)	11 (34)	6 (19)	1 (13)	10 (36)	20 (36)
41–50	16 (15)	4 (9)	7 (22)	5 (16)	0 (0)	4 (14)	12 (14)
51–60	17 (16)	4 (9)	7 (22)	6 (19)	2 (25)	1 (4)	14 (4)
>60	14 (13)	2 (4)	6 (19)	6 (19)	0 (0)	3 (11)	11 (11)
Gender, n (%)
Male	53 (48)	27 (57)	15 (47)	11 (35)	7 (88)	18 (64)	28 (38)
Female	56 (51)	19 (40)	17 (53)	20 (66)	1 (13)	10 (36)	45 (61)
Transgender	1 (1)	1 (2)	0 (0)	0 (0)	0 (0)	0 (0)	1 (0)
ppFEV1, n (%)
<30%	1 (1)	0 (0)	0 (0)	1 (3)	0 (0)	0 (0)	1 (0)
30%–50%	18 (16)	9 (19)	5 (16)	4 (13)	1 (13)	4 (14)	13 (18)
51%–70%	29 (26)	14 (30)	7 (22)	8 (26)	1 (13)	7 (25)	21 (28)
71%–90%	29 (26)	17 (36)	10 (31)	2 (6)	3 (38)	9 (32)	17 (23)
>90%	23 (21)	7 (15)	7 (22)	9 (29)	3 (38)	7 (25)	13 (18)
Don't know	10 (9)	0 (0)	3 (9)	7 (23)	0 (0)	1 (0)	9 (12)
PEx treated with PO ABx in prior year, n (%)
None	45 (41)	18 (38)	16 (50)	11 (35)	4 (50)	15 (53)	26 (35)
1–2	41 (37)	20 (43)	10 (31)	11 (35)	2 (25)	9 (32)	30 (41)
3–4	14 (13)	6 (13)	2 (6)	6 (19)	2 (25)	3 (11)	9 (12)
>4	8 (7)	2 (4)	4 (13)	2 (6)	0 (0)	1 (4)	7 (9)
Don't know	2 (2)	1 (2)	0 (0)	1 (3)	0 (0)	0 (0)	2 (0)
PEx treated with IV ABx in prior year, n (%)
None	83 (76)	33 (70)	25 (78)	25 (81)	6 (75)	23 (82)	54 (73)
1–2	18 (16)	9 (19)	5 (16)	4 (13)	2 (25)	4 (14)	12 (16)
3–4	3 (3)	2 (4)	1 (3)	0 (0)	0 (0)	0 (0)	3 (0)
>4	5 (5)	2 (4)	1 (3)	2 (6)	0 (0)	1 (4)	4 (1)
Don't know	1 (1)	1 (2)	0 (0)	0 (0)	0 (0)	0 (0)	1 (0)

Cannabis-containing products

Of the 110 respondents, 79 (72%) had tried cannabis-containing products at least once (ie, ever-user) and 47 (43%) considered themselves a current user. Indication(s) for use and source of cannabis-containing products are summarised in table 2. Of ever-users, 25% reported an increased frequency of cannabis use after legalisation in Canada. For current users, overall and preferred formulation(s) are depicted in online supplemental appendix figures 1 and 2, respectively. Edibles were reported as the most commonly used cannabis formulation (n=41, 87%) as well as the most preferred (n=28, 60%). Vaping with an e-cigarette and/or other handheld device was reported as the second most common route of use (n=21, 45%) and preference (n=12, 26%), while smoking a joint or blunt and drops or tinctures were both the third most common reported route of use (both n=14, 30%) and preference (n=12, 26% and n=8, 17%, respectively). Of current users, 53% (n=25) reported using at least one inhaled cannabis formulation. Reasons respondents indicated for preferred formulations included convenience, onset and duration of effect, and lesser potential for harming the lungs (for non-inhaled routes).

Table 2Reported cannabis-containing product use and source of supply

Outcome	n (%)
Impact of legalisation of cannabis-containing products in Canada in October 2018 on frequency of use (n=79)^*
No change in frequency of use	55 (70)
Increased frequency of use	20 (25)
Unsure about impact on frequency of use	4 (5)
Duration of time using cannabis-containing products (n=47)^†
<1 year	4 (9)
1–3 years	22 (47)
4–6 years	7 (15)
7–10 years	4 (9)
>10 years	10 (21)
Frequency of cannabis-containing product use (n=47)^†
Less than monthly	4 (9)
Less than weekly, but at least once monthly	10 (21)
1–2 days per week	10 (21)
3–5 days per week	8 (17)
6–7 days per week	15 (32)
Indication for use of cannabis-containing products (n=47)^†
Recreationally	7 (15)
Medically to manage symptoms	9 (19)
Both recreationally and medically to manage symptoms	31 (66)
Source of cannabis-containing product supply (n=47)^†^‡
Government-licensed dispensary	29 (62)
Unlicensed dispensary	15 (32)
Unlicensed dealer	7 (15)
Grow own supply	4 (9)
Friend or family member	14 (30)
Prefer not to say	2 (4)
Other^§	1 (2)

Thirty (64%) current users indicated cannabis somewhat or significantly improved their quality of life, 10 (21%) indicated it did not affect their quality of life, and 3 (6%) indicated it somewhat or significantly decreased their quality of life (online supplemental appendix table 2). Forty (85%) current users reported using cannabis for medical reasons; 9 (23%) of these individuals reported only using cannabis medically, while the remainder reported using cannabis both medically and recreationally. Self-reported effectiveness of cannabis for managing CF-related symptoms is summarised in table 3. The most common symptoms respondents reported treating were stress (85%), insomnia/lack of sleep (83%), anxiety (83%), joint pain (73%), and low appetite (71%). Cannabis-containing products were often reported to be just as or more effective than other medications for symptom management (table 3).

Table 3Reported medical indications for cannabis use and effectiveness for symptom management

Symptom	Effectiveness of cannabis to manage symptom (N=40^*), n (%)			Effectiveness of cannabis to manage symptom versus other prescription or non-prescription medications (N=31^†^‡), n (%)
Symptom	Very or somewhat effective^§	Very or somewhat ineffective^¶	Unsure	Cannabis more effective^**	Cannabis just as effective	Cannabis less effective^††	Unsure
Insomnia/lack of sleep	31 (78)	2 (5)	0 (0)	18 (58)	2 (7)	2 (7)	3 (10)
Stress	30 (75)	4 (10)	0 (0)	13 (42)	4 (13)	2 (7)	4 (13)
Anxiety	29 (73)	2 (5)	2 (5)	11 (36)	4 (13)	2 (7)	8 (26)
Joint pain	24 (60)	5 (13)	0 (0)	11 (36)	10 (32)	0 (0)	3 (10)
Low appetite	23 (58)	4 (10)	1 (3)	14 (46)	2 (7)	0 (0)	4 (13)
Depression	20 (50)	3 (8)	3 (8)	12 (39)	1 (3)	2 (7)	6 (19)
Abdominal pain	16 (40)	2 (5)	2 (5)	4 (13)	10 (32)	2 (7)	2 (7)
Migraine/headache	14 (35)	2 (5)	2 (5)	6 (19)	3 (10)	2 (7)	5 (16)
Chest pain	11 (28)	2 (5)	2 (5)	5 (16)	5 (16)	3 (10)	3 (10)
Nausea	10 (25)	2 (5)	3 (8)	7 (23)	2 (7)	0 (0)	6 (19)
Airway inflammation	7 (18)	2 (5)	8 (20)	2 (7)	3 (10)	1 (3)	9 (29)
Sinus pain	7 (18)	0 (0)	5 (13)	1 (3)	3 (10)	2 (7)	3 (10)
Other	3 (8)^‡‡	0 (0)	9 (23)	0 (0)	0 (0)	0 (0)	10 (32)

From the 35 respondents who reported their average cannabis dose, responses varied widely. The most common dose reported for edibles was 10–20 mg, though some used upwards of 100 mg. The amount smoked ranged from 0.25 g to 2 g or 0.5–2 joints, and between 0.2 mL and 1 mL of oils or tinctures up to two times per day were reported. Most (n=29, 62%) preferred products with both THC and cannabidiol (CBD), of whom the majority (n=19, 66%) preferred higher THC content. THC-only products were preferred by seven (15%) respondents and two (4%) preferred CBD-only products.

When considering potential short-term and long-term side effects associated with cannabis, a significantly greater proportion of non-users (ie, ‘past users’ and ‘never users’) reported perceiving them to be ‘somewhat’ or ‘very’ concerning (online supplemental appendix table 3). For current cannabis users, a greater proportion of those who use inhaled formulations reported perceiving respiratory-related side effects to be ‘somewhat’ or ‘very’ concerning compared with those who do not use inhaled formulations (online supplemental appendix table 4). When comparing cigarettes and cannabis-containing products for the potential for addiction and dependence, physical harm, and negative impacts on mental health, current users reported perceiving cannabis to be significantly safer than cigarettes when compared with non-users (figure 1A). Fifteen (14%) respondents indicated their perceptions about cannabis changed after legalisation in Canada; the proportion of cannabis users versus non-users who reported having a change in perception was not significantly different (p=0.48). In general, respondents indicated they felt cannabis was less stigmatised, felt more open to ask questions and discuss cannabis with their doctors, and felt more informed about symptoms cannabis may be used to treat, potential side effects, and different formulations. Most respondents (n=85, 77%) indicated they were aware that THC and CBD can interact with other medications.

Twenty-two (20%) respondents provided general comments about cannabis use. Some expressed that the use of cannabis provides agency with self-medicating, it can be helpful for symptom management, and it provides a safer alternative to medications such as narcotics. Others expressed concerns, including potential negative impacts on lung and mental health, memory impairment, risk of developing schizophrenia (particularly in youth), and the need for moderation when used. Also expressed was hope for increased access to advice about medical indications for cannabis, how to use cannabis, and non-inhaled routes of administration.

Vaping

Of the 110 respondents, 36 (33%) had tried vaping of any kind, but only 8 (7%) considered themselves a current vaper, with most vaping at least 3 days weekly (n=6, 75%). Current vapers reported using a vaping pen (n=5, 63%) or e-cigarette device (n=3, 38%), and none reported use of a water pipe or bong. Marijuana and THC/CBD oil were the most commonly vaped products reported (both n=4, 50%), followed by nicotine (n=3, 38%), and THC-only oil (n=2, 25%). No respondents reported vaping CBD-only oil, tobacco, or flavoured liquid.

The majority of respondents indicated they perceived vaping as ‘very’ or ‘somewhat’ unsafe, though marijuana and THC and/or CBD were generally deemed safer than nicotine, tobacco, or flavoured liquid (online supplemental appendix table 5); for all products except nicotine, the difference in perceived safety of products did not vary significantly by lung function (online supplemental appendix table 6). Most respondents indicated there were short-term or long-term side effects of concern associated with vaping (online supplemental appendix table 5). Overall, the largest proportion of respondents reported perceiving that vaping was just as likely as cigarettes to cause addiction or dependence, physical harm, and negatively affect mental health, though there was more uncertainty for the latter (figure 1B). Forty-nine (45%) respondents indicated the 2019 media attention to EVALI and associated deaths changed their perceptions about potential short-term and long-term effects associated with vaping; of these 49 individuals, 27% (n=13) reported they had tried vaping before and 4% (n=2) identified as a current vaper. Reported changes in perception included being more aware of: potential harms of vaping, even in the non-CF population; solvents/carrier fluids can cause harm; lack of regulation for vaping products; and the possibility for vaping to cause more and/or different kinds of harm compared with cigarettes. Eleven (10%) respondents indicated they were not aware of any media attention.

Comfort discussing cannabis-containing products and/or vaping with the CF healthcare team

The majority (n=85, 77%) reported feeling comfortable talking to the CF healthcare team about use of cannabis and/or vaping, while 14 (13%) reported not feeling comfortable and 11 (10%) were unsure. Many respondents suggested that establishing an open, non-judgemental environment is necessary in order to feel safe discussing these topics with their healthcare team. Additional suggestions included: making these discussions part of routine care for all patients; for conversations to be scientific with knowledge about medical uses of cannabis and potential risks versus benefits; having empathy for why patients may smoke and to understand that benefits experienced may outweigh potential side effects, stigma, and shame; ensuring use of cannabis will not affect future healthcare-related decisions and opportunities; making conversations anonymous or virtual; and hosting online round-table discussions with patient partners who have used cannabis. One respondent indicated the question of how to create a safe space for these discussions may contribute to stigma since cannabis is now legal in Canada.

Discussion

In this population of adults with CF or CFTR-related disorder, increased frequency of cannabis use following legalisation was reported by 43% of cannabis ever users and 28% of current users. Perceptions of cannabis were only reported to have changed in a minority (14%) of respondents after legalisation, with changes reflecting improved knowledge about cannabis and less stigma surrounding it. EVALI media attention was reported to have changed almost half of respondents’ perceptions about the safety of vaping, with increased awareness of the potential for vaping to cause harm.

The proportion of respondents identifying as cannabis ever-users (72%) and current users (43%) in our study was higher than previously reported for pwCF, which has ranged from 3% to 31% (the majority being approximately 10%).¹²,¹⁹ Some of this contrast may be due to differences in legal access to cannabis. Previous studies in pwCF were conducted in regions where/when recreational cannabis use was illegal, and most had no legal medical cannabis programs. In one study conducted at six US CF centres, although 15% of respondents had used marijuana for medical purposes within the past 12 months, 46% indicated they would be interested in doing so if it was legally available.¹⁶ If comparing with the general population in BC, 32% of respondents to the 2021 BC Cannabis Use Survey reported having used cannabis within the past 12 months, which was an increase from 28% prelegalisation in 2018.²⁵

Legal access to cannabis may not be the only factor contributing to the observed results. The higher rate of cannabis use reported in this study could also be related to the COVID-19 pandemic, which was ongoing throughout the survey period. Although this was not explored specifically in this study, of the respondents to the 2021 BC Cannabis Use Survey who used cannabis, 24% reported increased use during the pandemic.²⁵ Similarly, of respondents to the Canadian Cannabis Survey 2021 who had used cannabis within the past 12 months, 29% reported an increase in use as a result of the pandemic.²⁶ Therefore, considering the cannabis usage trends in the general population, it is possible that the proportion of respondents identifying as ever- users or current users of cannabis in this study could have been lower if the study had been conducted before the COVID-19 pandemic.

The majority (85%) of current cannabis users in the present study reported using it medically. Over 50% of respondents using cannabis medically reported they were treating symptoms of insomnia, stress, anxiety, joint pain, low appetite, depression, and/or abdominal pain; these indications are among those reported previously for pwCF,^{14 16 18} as well as the general population of BC, Canada, and the USA.^{25 27} The majority of respondents in the present and past studies in pwCF reported the use of cannabis as being effective for treating their symptoms, important for their health, and improving their quality of life;^{14 16 18} this is important because symptoms such as pain, fatigue, difficulty sleeping, and anxiety are commonly experienced by pwCF and can cause significant distress.²⁸ The majority of respondents in the present study reported cannabis was equally if not more effective than other medications; however, details about trials of other pharmacological and non-pharmacological interventions were not solicited in the questionnaire. Medical use of cannabis has been reported to decrease use of other medications,^{26 27} including opioid and non-opioid analgesics, anti-inflammatories, sedatives, and antidepressants.²⁷ However, substituting without medical oversight can result in negative outcomes such as withdrawal from the discontinued therapy, recurrence of the underlying symptoms if the discontinued therapy is necessary and/or the cannabis is not effective, as well as clinically relevant drug-drug interactions. It is also important to ensure that patients who choose to self-initiate cannabis for symptom management have received education about first-line treatment alternatives to address the underlying cause of their symptom(s), and are aware of potential short-term and long-term adverse effects associated with cannabis that may outweigh the benefits they report with use.

Almost a quarter of respondents in the present study indicated they were not aware that cannabis can interact with other medications. In vitro data suggest THC and CBD inhibit specific cytochrome P450 (CYP) enzymes, and clinically relevant drug-drug interactions have been reported.²⁹ Notably, CBD may inhibit CYP3A4, which the CFTR modulators ivacaftor, tezacaftor, and elexacaftor are substrates of.³⁰ The impact of cannabis on the pharmacokinetics of CFTR modulators has not been evaluated, but cannabis and CBD may inhibit their metabolism, thereby increasing exposure and the risk of adverse effects. It is prudent that prescribers and pharmacists caring for pwCF be aware of patients’ cannabis use so potential interactions can be identified, and a management and monitoring plan can be established with the patient.

The most commonly used formulations of cannabis identified in our study were similar to those recently reported in another study in pwCF.¹⁶ Specifically, edibles were reported as the most commonly used and preferred route of administration, followed by vaporised, and then smoked.¹⁶ A likely reason edible formulations are most commonly used by pwCF (vs smoked in the general population^{26 31}) is the lower potential to harm the lungs; this is reflected in our study, where potential lung-related and respiratory-related side effects were reported as the most common to cause respondents concern. Interestingly, those who reported use of inhaled formulations of cannabis perceived these side effects as more concerning than cannabis users who do not use inhaled formulations. These users may still smoke or vape cannabis because of convenience, quick onset and shorter duration compared with edibles, and if benefits experienced outweigh the potential risks.

One study involving adolescents and young adults with CF conducted after the EVALI outbreak reported that no respondents identified as being recent smokers, and risk of significant lung damage in the short-term of e-cigarette use was widely recognised.³² In the present study, although 7% of respondents identified as current vapers, this is much lower than those who reported having tried vaping. The difference in use of current vapers versus ever-vapers may be due to changes in perception of vaping since the 2019 media attention to EVALI and associated deaths. Studies conducted in youth before and after the EVALI outbreak indicate perceived risks associated with e-cigarette use increased after the outbreak,^{33 34} while perceived benefits decreased.³³ Ten per cent of respondents in the present study indicated they were not aware of the 2019 EVALI media attention, and a notable proportion were either unsure or reported no concern for potential short-term and long-term side effects with vaping. This highlights the need for CF healthcare providers to educate patients and fill any knowledge gaps related to the potential harms of vaping. Especially relevant to pwCF are data suggesting vaping e-liquids with propylene glycol and/or vegetable glycerin has the potential to cause CFTR channel dysfunction, potentially more so than cigarettes if the e-liquid also contains nicotine.^{35 36}

Despite the notable proportion of reported cannabis use and vaping in our survey sample, it is often not routine to discuss this with patients. As one respondent suggested, making discussions about cannabis and/or vaping part of routine care may increase comfort discussing with the CF healthcare team. A 2018 survey of clinicians from CF centres in the USA indicated only 15% of respondents ‘Always’ asked patients about cannabis use, while 48%, 25%, and 11% asked ‘Sometimes’, ‘Rarely’, or ‘Never’, respectively.³⁷ Moreover, once a patient was identified as using cannabis, the reason for use was ‘Always’ determined only 68% of the time, while method/route and frequency of use were ‘Always’ determined 85% and 75% of the times, respectively.³⁷ These results highlight voids in discussions regarding cannabis use. Soliciting details regarding cannabis use is important, not only for understanding its role in patients’ care, but also for identifying important opportunities for education. A review of considerations for cannabis use in adolescents with CF addresses the importance of routine screening for cannabis use, with key discussion elements being a neutral, empathetic and non-judgmental approach; active listening; and fostering an environment where patients feel safe and heard.³⁸ Respondents in the present study also expressed a desire for the CF healthcare team to be informed about medical uses of cannabis and weighing risks versus benefits when discussing with patients. In the 2018 survey of CF clinicians, only 26% of respondents felt ‘Extremely’ or ‘Very’ prepared to answer patients’ questions about cannabis, while 11% were ‘Not at all’ prepared.³⁷

Important limitations of this study were the relatively low questionnaire completion rate and potential selection bias; therefore, responses may not reflect views of the overall clinic cohort. The low completion rate could be due to the length of the questionnaire and lack of an incentive (eg, cash stipend, prize draw, etc) for completion. Generalisability is further limited by not including adolescents, an age group with prevalent cannabis use and vaping,^{26 31} and whose perceptions may differ from adults. This study also included people with CFTR-related disorder, a population for which there is an absence of literature regarding this topic; whether respondents had CF versus CFTR-related disorder was not asked in this study. However, individuals with CFTR-related disorder represent a minority of our clinic population (~15%) and therefore it is unlikely they would have heavily influenced the survey results. Furthermore, all patients followed in our clinic receive the same level of care and education regarding the use of cannabis and/or vaping. Being a single-centre study, responses may not be reflective of adults receiving care from other CF clinics in or outside of Canada. Results also may not be generalisable to other countries, particularly those with different laws surrounding cannabis. CFTR modulator use was not assessed; however, it is unlikely this would have influenced survey results, as CFTR modulators were not widely accessible when the survey was conducted. Since this time, CFTR modulators have become more widely available. It is possible that CFTR modulator use could impact the prevalence and/or reasons for cannabis use and therefore the generalisability of the study results to present-day (eg, CFTR modulator therapy can improve abdominal symptoms in some individuals,³⁹ which could decrease prevalence of cannabis use for these symptoms). Whether being post-transplant affected responses could not be evaluated, as transplant status was not assessed. As previously mentioned, this study was conducted during the COVID-19 pandemic, which is reported to have affected the use of cannabis in the general population.^{25 26} Finally, the results of this study are based on perceptions and responses reported by study participants; they do not answer whether cannabis used for symptom management was clinically appropriate or whether first-line pharmacological and non-pharmacological options were optimised before initiating cannabis.

Despite the aforementioned limitations, this study is an important addition to the growing body of literature regarding this topic, highlighting opportunities for improvement in healthcare providers’ assessment and communication about cannabis and vaping as well as unanswered questions that may be addressed in future research.

Conclusion

Use of cannabis was common in this sample of adults with CF and CFTR-related disorder, and has increased since its legalisation in Canada. Although the EVALI media attention increased awareness for potential harms associated with vaping, there still exist gaps in knowledge about this. Cannabis use and vaping should be routinely and openly discussed during CF clinic visits so that healthcare providers can ensure patients receive education about evidence for potential risks versus benefits, and ultimately support patients in making informed decisions about cannabis use and vaping.

Supplementary material

Footnotes

Footnote Group

Data availability statement

All data relevant to the study are included in the article or uploaded as supplementary information.

References

Untitled section

References

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Associated Data

Supplementary Materials

Data Availability Statement

All data relevant to the study are included in the article or uploaded as supplementary information.

Studies

Conditions

Cannabinoids and active compounds

Related research

Abstract

Background

Methods

Results

Conclusions

Untitled section

Article notes

Untitled section

Author notes

Boxed Text

WHAT IS ALREADY KNOWN ON THIS TOPIC

WHAT THIS STUDY ADDS

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

Introduction

Methodology

Patient and public involvement

Participants

Analyses

Results

Cannabis-containing products

Vaping

Comfort discussing cannabis-containing products and/or vaping with the CF healthcare team

Discussion

Conclusion

Supplementary material

Footnotes

Footnote Group

Data availability statement

References

Untitled section

References

Associated Data

Supplementary Materials

Data Availability Statement

Additional materials