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.