1. Introduction
Cystic fibrosis (CF) is an autosomal recessive disease caused by
mutations in CFTR , a gene that encodes a chloride and bicarbonate
channel.1 Loss of CFTR function results in abnormal
mucus in the respiratory tract.2,3 Because patients
with CF have defects in mucociliary transport,2,4 CF
care guidelines recommend physical methods of airway clearance starting
at an early age.5 Several airway clearance methods are
routinely used in CF, including huff coughing, oscillating positive
expiratory pressure devices (PEP), high frequency chest wall oscillation
(vest), and aerobic or resistance exercise
training.6,7 Several studies have found no evidence
that any specific airway clearance technique is superior to
another,8,9 although people with CF may prefer certain
forms of airway clearance depending on age, developmental status, or
disease progression. Some studies also report differences between males
and females in airway clearance practices.7
While airway clearance treatments are almost universally prescribed,
they can be challenging for patients and families across the age
spectrum. Barriers to completing airway clearance may include time
commitment, lack of financial resources, perceived lack of
effectiveness, and discomfort. While care teams may recommend up to two
hours per day of airway clearance, actual use of these methods is often
far less than prescribed.10-12 Completing airway
clearance becomes increasingly difficult as children
age12 and are prescribed other therapies due to
disease progression. The teenage years are a time of low adherence to
airway clearance.10 Teens manage their CF while
maintaining busy academic, social, and extracurricular schedules with
progressively less parental supervision. Historically, this correlates
with a period of worsening lung function and increased
hospitalizations.13 Additionally, socioeconomic
factors significantly impact the ability to complete airway clearance.
Families with maternal college education, annual income
>$50,000, and more adults in the household have higher
completion of airway clearance.10 Airway clearance may
be painful or unpleasant for some patients. In hospitalized patients at
our center, we routinely observe refusal to complete physical therapy
and other forms of airway clearance due to lack of energy, fatigue,
shortness of breath, coughing, skin irritation, pain, or discomfort.
Furthermore, the effectiveness of some methods of airway clearance has
been questioned, particularly if not performed
correctly.14
The role of airway clearance for patients with CF could change with the
introduction of CFTR modulator drugs.15-19 These
medications increase the activity of endogenous CFTR and cause immediate
improvements in mucociliary transport,20 pulmonary air
trapping,21 and lung function.15-19This raises questions about the future role or need for airway clearance
in people with CF following initiation of highly effective CFTR
modulator drugs. Surveys of patients using CFTR modulators show that
most (292/359, 81%) have not discontinued chronic treatments, although
respondents ranked airway clearance techniques as their most burdensome
treatment.22
To assess usage of airway clearance, identify barriers to regular use,
and understand why some methods of airway clearance are preferred over
others, we administered an anonymous survey to patients and caregivers
in our pediatric and adult CF center. We hypothesized that adolescent
patients (patients ages 10-19 years) would report less time using airway
clearance methods compared to adults or younger children, and that
patients would prefer forms of airway clearance that are convenient or
coordinate better with other therapies. Additionally, we hypothesized
that many forms of airway clearance are not completed because they are
painful, unpleasant, or poorly tolerated. We considered that male and
female patients could use different forms of airway clearance during
adolescence and experience side effects differently. Finally, we
predicted that patients taking CFTR modulators would report less airway
clearance because of improved health.