2. Materials and Methods
2.1 Ethics Statement
This study was approved by the University of Iowa’s Institutional Review
Board (IRB), Study # 202008392. A waiver of documentation of consent
was granted by the IRB. Subjects indicated their informed consent to
participate in the study by their answer to the first question of the
survey.
2.2 Survey creation
We developed a survey in REDCap based in part on the Cystic Fibrosis
Questionnaire – Revised (CFQ-R), a disease-specific instrument designed
to measure the impact of CF on health, perceived well-being, and
symptoms.23 The survey was modified and expanded to
obtain information on airway clearance usage, time commitment, and
medications. The survey consisted of six sections including: 1.
Demographics including age, gender, race, household size, education
level, and current employment or educational status; 2. Estimated time
commitment for their treatments including airway clearance; 3. Lifetime
experience with airway clearance methods; 4. Past 30-day airway
clearance use; 5. Current CF treatments including medications, CFTR
modulator therapies, and airway clearance; and 6. Perceived importance
of each treatment currently in use by the patient.
Demographic information including age and sex was collected because we
hypothesized that adolescent patients would be less likely to use airway
clearance and that male and female patients might have different
preferences. We used the World Health Organization definition of
adolescent as any persons 10-19 years old. Information on socioeconomic
status was requested, as this has been shown to correlate with airway
clearance adherence in previous studies.10
After the initial survey creation, several rounds of feedback were
collected from CF center physicians, physical therapists, and
pharmacists affiliated with the University of Iowa’s Carver College of
Medicine. A complete codebook for the survey is included in Supplemental
Information.
2.3. Recruitment
Patients or parents/guardians of minor patients were approached during
standard of care CF clinic visits at the University of Iowa Pediatric
and/or Adult CF centers. All eligible patients or their caregivers were
given an information sheet on how to access the computerized survey,
which could be completed during the clinic visit or at home following
the visit. The survey was voluntary and anonymous. Participants were
enrolled over a 7-month period (January 2021- August 2021). The goal
enrollment was 100 participants, which is roughly 40% of the combined
size of the pediatric and adult cystic fibrosis centers at the
University of Iowa. Surveys could be answered independently by a patient
with CF or by a parent, guardian, partner, or spouse on their behalf. In
this report, “respondent” refers to a person who answered the
survey and “patient” refers to a child or adult with CF whose health
and airway clearance practices are the subject of the survey. The term
“participant” is inclusive of both patients and respondents.
2.4 Statistical Analysis
RStudio (v1.2.5033) was used for statistical analysis. Analysis included
descriptive statistics and clustering. Given non-normal distribution of
some variables, non-parametric tests including a Wilcoxon rank sum test
(2 groups) or Kruskal-Wallis test (3 or more groups) were performed.
Fisher’s exact test was used for proportions. Generalized linear
modeling was utilized to analyze the relationship between airway
clearance usage or perceived importance as a function of age, gender,
and CFTR modulator usage. The heatmap function was used to display
patient/caregiver opinions of the positive and negative attributes of
each method of airway clearance.