Methods Used to Evaluate the Immediate Effects of Airway Clearance Techniques in Adults with Cystic Fibrosis: A Systematic Review and Meta-Analysis

Abstract

This review reports on methods used to evaluate airway clearance techniques (ACT) in adults with CF and examined data for evidence of any effect. Sixty-eight studies described ACT in adequate detail and were included in this review. Frequently reported outcomes were sputum expectoration (72%) and spirometric lung function (60%). Compared with cough alone, following any ACT, there was a trend for greater sputum wet weight, however FEV1 was not different. The mean (95% CI) within-group effect for sputum wet weight following any ACT was 12.43 g (9.28 to 15.58) (n = 30 studies) and for FEV1 was 0.03 L (−0.17 to 0.24) (n = 14 studies). Meta-regression demonstrated that, when compared with cough alone, greater sputum wet weight was reported in groups that received additional ACT by between 2.45 and 3.94 g (F3,66 = 2.97, p = 0.04). These data suggest the addition of ACT to cough alone may optimise sputum clearance; however, FEV1 lacked sensitivity to detect this change. Importantly, this review highlights the lack of appropriate measures to assess ACT efficacy.

A Novel Medical Device for Airway Clearance

“…Anuradha et al [ 32 ] studied the effectiveness of HS 3% on 10 children with non-CF bronchiectasis and found a reduction in exacerbation, and higher lung functions (FEV1, FVC) after 8 weeks [ 32 ]. In our study, the LibAirty system was found to be non-inferior to the PT arm of our study, and higher than the average yield of ACTs when compared to Chapman et al’s review [ 30 ].…”

“…A previous published review [ 30 ] investigated the endpoints of 70 studies on airway clearance for PwCF and found the average amount of mucus expectorated during airway clearance sessions to be 12.43 g for wet sputum. Furthermore, when split into PEP treatments into sub-groups, help expectorate the most sputum with an average of 13.76 g, while coughing alone was found to expectorate an average amount of 9.82 g. Those results correspond with the results of our study, where we found slightly higher amounts of mucus expectorated by the LibAirty system, with the BiPAP and the PT treatment producing an average amount of 14.35 g and 15.9 g, respectively.…”

A Novel Medical Device for Airway Clearance

“…Anuradha et al [ 32 ] studied the effectiveness of HS 3% on 10 children with non-CF bronchiectasis and found a reduction in exacerbation, and higher lung functions (FEV1, FVC) after 8 weeks [ 32 ]. In our study, the LibAirty system was found to be non-inferior to the PT arm of our study, and higher than the average yield of ACTs when compared to Chapman et al’s review [ 30 ].…”

“…A previous published review [ 30 ] investigated the endpoints of 70 studies on airway clearance for PwCF and found the average amount of mucus expectorated during airway clearance sessions to be 12.43 g for wet sputum. Furthermore, when split into PEP treatments into sub-groups, help expectorate the most sputum with an average of 13.76 g, while coughing alone was found to expectorate an average amount of 9.82 g. Those results correspond with the results of our study, where we found slightly higher amounts of mucus expectorated by the LibAirty system, with the BiPAP and the PT treatment producing an average amount of 14.35 g and 15.9 g, respectively.…”

Clinimetric analysis of outcome measures for airway clearance in people with cystic fibrosis: a systematic review

“…A recent systematic review and meta-analysis of OMs used to assess the immediate effects of ACT for adults with CF identified eleven different outcomes from studies completed between 1979 to August 2021, with the most frequently used being sputum weight in 72% of studies, and spirometry, especially FEV 1 in 60% of studies. 6 Similar to these results, a recent systematic review on outcomes and endpoints used in CF pulmonary exacerbation studies also reported a wide range of OMs used, 7 with FEV 1 being the most common.…”

“…Similar to Chapman et al , 6 a recent systematic review by Mcleod et al 7 investigating outcomes and endpoints used in CF pulmonary exacerbation studies reported a wide range of outcomes used, 7 with FEV 1 the most common. The authors of this review suggested that choice of OM may have historically been influenced by cost, available expertise, and equipment.…”

“…From our literature search and Chapman’s systematic review, 6 we note that many different OMs are being used in CF ACT research in addition to the traditional measures of FEV 1 and sputum weight. These include LCI derived from MBW tests, electrical impedance tomography, and a variety of radiological techniques including 3-helium MRI.…”

A Novel Medical Device for Airway Clearance

“…Anuradha et al [ 32 ] studied the effectiveness of HS 3% on 10 children with non-CF bronchiectasis and found a reduction in exacerbation, and higher lung functions (FEV1, FVC) after 8 weeks [ 32 ]. In our study, the LibAirty system was found to be non-inferior to the PT arm of our study, and higher than the average yield of ACTs when compared to Chapman et al’s review [ 30 ].…”

“…A previous published review [ 30 ] investigated the endpoints of 70 studies on airway clearance for PwCF and found the average amount of mucus expectorated during airway clearance sessions to be 12.43 g for wet sputum. Furthermore, when split into PEP treatments into sub-groups, help expectorate the most sputum with an average of 13.76 g, while coughing alone was found to expectorate an average amount of 9.82 g. Those results correspond with the results of our study, where we found slightly higher amounts of mucus expectorated by the LibAirty system, with the BiPAP and the PT treatment producing an average amount of 14.35 g and 15.9 g, respectively.…”

Clinimetric analysis of outcome measures for airway clearance in people with cystic fibrosis: a systematic review

“…A recent systematic review and meta-analysis of OMs used to assess the immediate effects of ACT for adults with CF identified eleven different outcomes from studies completed between 1979 to August 2021, with the most frequently used being sputum weight in 72% of studies, and spirometry, especially FEV 1 in 60% of studies. 6 Similar to these results, a recent systematic review on outcomes and endpoints used in CF pulmonary exacerbation studies also reported a wide range of OMs used, 7 with FEV 1 being the most common.…”

“…Similar to Chapman et al , 6 a recent systematic review by Mcleod et al 7 investigating outcomes and endpoints used in CF pulmonary exacerbation studies reported a wide range of outcomes used, 7 with FEV 1 the most common. The authors of this review suggested that choice of OM may have historically been influenced by cost, available expertise, and equipment.…”

“…From our literature search and Chapman’s systematic review, 6 we note that many different OMs are being used in CF ACT research in addition to the traditional measures of FEV 1 and sputum weight. These include LCI derived from MBW tests, electrical impedance tomography, and a variety of radiological techniques including 3-helium MRI.…”

A Novel Medical Device for Airway Clearance

“…Anuradha et al [ 32 ] studied the effectiveness of HS 3% on 10 children with non-CF bronchiectasis and found a reduction in exacerbation, and higher lung functions (FEV1, FVC) after 8 weeks [ 32 ]. In our study, the LibAirty system was found to be non-inferior to the PT arm of our study, and higher than the average yield of ACTs when compared to Chapman et al’s review [ 30 ].…”

“…A previous published review [ 30 ] investigated the endpoints of 70 studies on airway clearance for PwCF and found the average amount of mucus expectorated during airway clearance sessions to be 12.43 g for wet sputum. Furthermore, when split into PEP treatments into sub-groups, help expectorate the most sputum with an average of 13.76 g, while coughing alone was found to expectorate an average amount of 9.82 g. Those results correspond with the results of our study, where we found slightly higher amounts of mucus expectorated by the LibAirty system, with the BiPAP and the PT treatment producing an average amount of 14.35 g and 15.9 g, respectively.…”

Clinimetric analysis of outcome measures for airway clearance in people with cystic fibrosis: a systematic review

“…A recent systematic review and meta-analysis of OMs used to assess the immediate effects of ACT for adults with CF identified eleven different outcomes from studies completed between 1979 to August 2021, with the most frequently used being sputum weight in 72% of studies, and spirometry, especially FEV 1 in 60% of studies. 6 Similar to these results, a recent systematic review on outcomes and endpoints used in CF pulmonary exacerbation studies also reported a wide range of OMs used, 7 with FEV 1 being the most common.…”

“…Similar to Chapman et al , 6 a recent systematic review by Mcleod et al 7 investigating outcomes and endpoints used in CF pulmonary exacerbation studies reported a wide range of outcomes used, 7 with FEV 1 the most common. The authors of this review suggested that choice of OM may have historically been influenced by cost, available expertise, and equipment.…”

“…From our literature search and Chapman’s systematic review, 6 we note that many different OMs are being used in CF ACT research in addition to the traditional measures of FEV 1 and sputum weight. These include LCI derived from MBW tests, electrical impedance tomography, and a variety of radiological techniques including 3-helium MRI.…”