Results
Of the 226 subjects with CF who completed the one-time survey and met
inclusion criteria, current use was reported by 29% (n=66) of subjects
for marijuana, 22% (n=49) for CBD, 27% (n=60) for e-cigarettes, and
22% (n=49) for cigarettes. Only 0.9% (n=2) subjects used all four
substances, 6.2% (n=14) used three substances, and 22.6% (n=51) used
two of the substances currently (Figure 1).
The frequency of marijuana, CBD, e-cigarette, and cigarette usage varied
among those who reported current use. Daily or near-daily use was
highest in users of cigarette (45%, n=22) and e-cigarette (33%, n
=20). Marijuana users were more likely to use daily or near-daily (23%,
n=15) compared to CBD users (16%, n=8). A total of 39% (n=26) of
marijuana users, 33% (n=16) CBD, and 35% (n=21) e-cigarette users had
at least once a week usage compared to 22% (n=11) of cigarette users
(Figure 2).
Overall, we found that current users of each of the four substances were
more likely to be college-educated, between the ages of 26 and 39 years
old, and Black when compared to non-users. Demographic and socioeconomic
characteristics between current users and non-users differ depending on
the substance used (Table 1). Compared to non-users, current users of
CBD, e-cigarettes, and cigarettes were more likely to be male, which
contrasts with current marijuana users, who were slightly more likely to
identify as female and other gender identities. Black subjects were more
likely to be current users of all substances than other races.
Non-Hispanic white subjects were more likely to be current users of
marijuana and cigarettes. Asian, Native American, other races, or
multi-race subjects were more likely to be current users of
e-cigarettes. Specific to marijuana, there was no significant
association between current marijuana usage and state of residence in
terms of legality (illegal, medically legal, legalized).
Significant patterns also emerged with respect to markers of CF disease
severity and PHQ-4 scores between current users and non-users (Table 2).
Current marijuana users were more likely to be on pancreatic enzymes,
while current cigarette users were less likely to be on pancreatic
enzymes. Subjects with self-reported FEV1 percent
predicted of 60-80% were more likely to be current users of
e-cigarettes and cigarettes as compared to non-users who were more
likely to have a self-reported FEV1 less than 60% and
greater than 80%. There were no differences in pulmonary function
between current users and non-users of marijuana or CBD.
Current users of CBD, e-cigarettes, and cigarettes were more likely to
have an abnormal mental health screen by PHQ-4 compared to non-users.
CBD users were more likely than non-users to have a severe score on the
PHQ-4, report depressive symptoms on the PHQ-4, but there was no
difference in anxiety symptoms. E-cigarette and cigarette users were
more likely to have a mild, moderate, and severe score on the PHQ-4 than
non-users, as well as, more likely to report anxiety and depressive
symptoms on the PHQ-4. There was no significant difference found in
mental health between users and non-users of marijuana.
There were differences in CFTR modulator use between current-users and
non-users of substances. Current marijuana users were 1.92 times more
likely to report being on CFTR modulators in univariate logistic
regression (95% CI 0.87-4.70, p=0.1) and 2.45 times more likely in the
multivariate logistic model adjusted for age, gender, race, ethnicity,
ppFEV1, and PHQ-4 (95% CI 0.97-7.17, p=0.08). Current
users of e-cigarettes were 4.07 times more likely to report taking CFTR
modulators (95% CI 1.54-14.07, p=0.01) in the univariate logistic
regression, and 2.92 times more likely in the multivariate analysis
adjusted for age, gender, race, ethnicity, ppFEV1, and
PHQ-4 (95%CI 0.98-11.00, p=0.08). Although the differences for both
marijuana and e-cigarettes did not reach statistical significance, the
confidence intervals exclude any meaningful differences of lower CFTR
modulator use in current substance users compared to non-users. There
were no significant differences in current cigarette or CBD users by
CFTR modulator use in logistic regressions (Table 3).