3 Results
3.1 Summary of survey respondents.
Surveys were provided to participants at regular CF clinic visits to the adult or pediatric CF centers at the University of Iowa. Demographic information is summarized in Table 1. Of the 174 surveys distributed in clinic, 60 respondents started the survey, and 52 completed the survey. Survey respondents identified themselves as either patients (N=45) or parents/guardians (N=14). 56 respondents identified the patient’s gender, including 31 male and 25 female. The median age of the patients was 20 years. Self-reported race/ethnicity of the patients included White (51), American Indian/Alaska Native (1), Black/African American (1), and Other (2). The median FEV1 was 90% of predicted among the 28 patients whose lung function results were recorded.
3.2 Familiarity with airway clearance methods.
Survey respondents reported familiarity with multiple forms of airway clearance, Table 2. The median lifetime number of airway clearance methods experienced per patient was 4. High frequency chest wall oscillation (vest), huff coughing, manual chest physiotherapy, exercise, and PEP devices were the most reported methods.
3.3 Current use of airway clearance methods, effect of age and gender.
Past 30-day usage was highest for exercise and vest. Although 46 respondents reported experience with manual chest physical therapy (CPT) during their lifetimes, only 7 reported using manual CPT over the past 30 days, and none of the patients reported recent use of intrapulmonary percussive ventilation (IPV). There were trends towards higher current use of vest by females and exercise by males, but these were not statistically significant, Figure 1A. Current use of manual CPT tended to be reported for younger patients, but there were no statistically significant differences (p=0.17) in age between current users of any of the common airway clearance methods, Figure 1B.
3.4 Perceived importance of airway clearance in relationship to other therapies.
People with CF receive many classes of treatment in addition to airway clearance, including nutritional therapies, antibiotics, mucolytic drugs, and CFTR modulators. Survey respondents were asked which classes of treatment they use. For each treatment class, respondents were asked to rate the importance of that treatment to their health on a sliding scale from 0-100. The default level of importance was set to 50. Respondents regarded CFTR modulator therapies as the most important treatment class, with a median importance of 99.5 (p < 0.0001), Figure 2. Exercise was considered less important than CFTR modulators (median importance 88, p=0.007 vs. CFTR modulators), but more important than other forms of airway clearance, mucolytics, or oral antibiotics (all p<0.05 vs. exercise). There were no significant differences between the remaining classes of treatments. For each of these remaining treatment classes, including airway clearance, the median importance was rated significantly higher than the default value of 50.
3.5 Importance of airway clearance: role of sex and CFTR modulator therapy.
There was wide dispersion of perceived importance of airway clearance, Figure 2. To understand which factors potentially influence patient attitudes about airway clearance, multivariable regression analysis was performed to determine whether age, sex, or CFTR modulator use were associated with the perceived importance of airway clearance, Supplemental Data 1. Respondents rated airway clearance lower in importance if the patient was male (effect size 18 points lower, P = 0.039) or used elexacaftor/tezacaftor/ivacaftor (effect size 39 points lower, P = 0.047). Age was not statistically significant in this model.
Exercise is regarded by some as an alternative form of airway clearance.24,26 In this survey, exercise was considered important for maintaining health by most respondents. In contrast to other methods of airway clearance, the perceived importance of exercise was rated highly regardless of age, sex, or CFTR modulator use, (see Supplemental Data 2).
3.6 Reported time commitment for airway clearance.
Airway clearance treatments can be time consuming. Survey respondents were asked to select the amount of time spent on daily treatments from a list of choices including none, only when sick, less than 30 minutes, 30-59 minutes, 1-2 hours, or more than 2 hours. Total daily time required to complete all treatments was compared by past 30-day use of different airway clearance methods. The most common response provided was between 1-2 hours per day on treatments. However, 19% of respondents reported spending less than 30 minutes per day. (Supplemental Data 3) Respondents who used vest therapies for airway clearance within the past 30 days had the highest median time commitment, Figure 3. There was a trend towards more time commitment to airway clearance for female patients, although this was not statistically significant. Time commitment did not correlate significantly with age, CFTR modulator use or any type of airway clearance method other than vest (p<0.0001 for vest, p >0.05 for all other associations). Over half of respondents receiving a CFTR modulator (23/43 = 53%) reported that treatment time for airway clearance had been reduced since starting this medication, Table 3.
3.7 Positive attributes of different airway clearance methods.
To determine why some airway clearance methods are preferred, survey respondents were asked to indicate what they like about each airway clearance they have used in their lifetime. Respondents could make multiple selections, including whether the method takes little time, is comfortable, works well with other treatments, is effective, or feels good or healthy. To allow for neutral or negative responses to the question, choices of “nothing”, “other”, and “I don’t know” were provided. The positive attributes for each airway clearance method were tabulated and clustering analysis was performed to determine which of these attributes was associated with each method, Figure 4A. Vest users rated this method as being compatible with other treatments. Exercise was the most likely to be selected as healthy or feeling good. Users liked oscillating PEP devices because of low time commitment.
3.8 Negative attributes of different airway clearance methods.
Survey respondents were asked to indicate what they dislike about each method of airway clearance they have experienced in their lifetime. Respondents could select multiple options, including shortness of breath, time consuming, painful, uncomfortable, less effective than other treatments, not compatible with other treatments, or if the method is unpleasant or embarrassing. To allow for neutral/positive responses to the question for each method, choices of “nothing” and “I don’t know” were provided. The most common reason people disliked vest treatment was time commitment, Figure 4B. Respondents reported that manual CPT was uncomfortable, exercise was most likely to cause shortness of breath, and PEP was the most likely to be considered ineffective.
3.9 Location of pain or discomfort caused by different airway clearance methods.
Manual CPT and vest users were the most likely to report pain and discomfort. The most common locations for pain or discomfort were the chest (N = 19), abdomen (N = 12), back (N = 10), and breasts (N = 10), Table 4.