The ECFS-CTN Standardisation Committee has undertaken this review of lung clearance index as part of the group's work on evaluation of clinical endpoints with regard to their use in multicentre clinical trials in CF. The aims were 1) to review the literature on reliability, validity and responsiveness of LCI in patients with CF, 2) to gain consensus of the group on feasibility of LCI and 3) to gain consensus on answers to key questions regarding the promotion of LCI to surrogate endpoint status. It was concluded that LCI has an attractive feasibility and clinimetric properties profile and is particularly indicated for multicentre trials in young children with CF and patients with early or mild CF lung disease. This is the first article to collate the literature in this manner and support the use of LCI in clinical trials in CF.

Devices such as the Acapella may facilitate independent airway clearance, however, few clinical trials have investigated the efficacy of Acapella. The aim of this study was to compare the effectiveness of Acapella to 'usual airway clearance' in adults during an acute exacerbation of bronchiectasis requiring oral antibiotic therapy. Twenty patients with bronchiectasis and an acute exacerbation requiring oral antibiotic therapy were recruited into a randomized crossover trial. Patients were allocated to one of two groups determined by concealed computer generated randomization. Group 1 (n=10): airway clearance session using Acapella at home twice daily during oral antibiotic therapy. Group 2 (n=10): 'usual' airway clearance sessions at home during oral antibiotic therapy. Patients recorded duration of each treatment session, volume of sputum produced and perception of breathlessness. An independent assessor performed outcome measures of spirometric lung function, pulse oximetry and breathlessness at the beginning and end of the study period. The mean volume of sputum expectorated during Acapella sessions was greater than for usual airway clearance sessions although this difference was not significant 2.61 ml (95% CI-1.62 to 6.84). Mean duration of Acapella sessions was greater than usual airway clearance sessions and approached significance. There were no significant between group differences in changes in lung function. This study demonstrates that the Acapella device may offer an acceptable, user-friendly method of airway clearance in patients with bronchiectasis.

In patients with cystic fibrosis, cystic fibrosis transmembrane conductance regulator (CFTR) biomarkers, such as sweat chloride concentration and/or nasal potential difference, are used as end-points of efficacy in phase-III clinical trials with the disease modifying drugs ivacaftor (VX-770), VX809 and ataluren. The aim of this project was to review the literature on reliability, validity and responsiveness of nasal potential difference, sweat chloride and intestinal current measurement in patients with cystic fibrosis.Data on clinimetric properties were collected for each biomarker and reviewed by an international team of experts. Data on reliability, validity and responsiveness were tabulated. In addition, narrative answers to four key questions were discussed and agreed by the team of experts.The data collected demonstrated the reliability, validity and responsiveness of nasal potential difference. Fewer data were found on reliability of sweat chloride concentration; however, validity and responsiveness were demonstrated. Validity was demonstrated for intestinal current measurement, but further information is required on reliability and responsiveness. For all three end-points, normal values were collected and further research requirements were proposed.This body of work adds useful information to support the promotion of CFTR biomarkers to surrogate end-points and to guide further research in the area.

BackgroundThe impact of bronchiectasis on sedentary behaviour and physical activity is unknown. It is important to explore this to identify the need for physical activity interventions and how to tailor interventions to this patient population. We aimed to explore the patterns and correlates of sedentary behaviour and physical activity in bronchiectasis.MethodsPhysical activity was assessed in 63 patients with bronchiectasis using an ActiGraph GT3X+ accelerometer over seven days. Patients completed: questionnaires on health-related quality-of-life and attitudes to physical activity (questions based on an adaption of the transtheoretical model (TTM) of behaviour change); spirometry; and the modified shuttle test (MST). Multiple linear regression analysis using forward selection based on likelihood ratio statistics explored the correlates of sedentary behaviour and physical activity dimensions. Between-group analysis using independent sample t-tests were used to explore differences for selected variables.ResultsFifty-five patients had complete datasets. Average daily time, mean(standard deviation) spent in sedentary behaviour was 634(77)mins, light-lifestyle physical activity was 207(63)mins and moderate-vigorous physical activity (MVPA) was 25(20)mins. Only 11% of patients met recommended guidelines. Forced expiratory volume in one-second percentage predicted (FEV1% predicted) and disease severity were not correlates of sedentary behaviour or physical activity. For sedentary behaviour, decisional balance ‘pros’ score was the only correlate. Performance on the MST was the strongest correlate of physical activity. In addition to the MST, there were other important correlate variables for MVPA accumulated in ≥10-minute bouts (QOL-B Social Functioning) and for activity energy expenditure (Body Mass Index and QOL-B Respiratory Symptoms).ConclusionsPatients with bronchiectasis demonstrated a largely inactive lifestyle and few met the recommended physical activity guidelines. Exercise capacity was the strongest correlate of physical activity, and dimensions of the QOL-B were also important. FEV1% predicted and disease severity were not correlates of sedentary behaviour or physical activity. The inclusion of a range of physical activity dimensions could facilitate in-depth exploration of patterns of physical activity. This study demonstrates the need for interventions targeted at reducing sedentary behaviour and increasing physical activity, and provides information to tailor interventions to the bronchiectasis population.Trial registrationNCT01569009 (“Physical Activity in Bronchiectasis”)Electronic supplementary materialThe online version of this article (doi:10.1186/s12890-015-0046-7) contains supplementary material, which is available to authorized users.

The LifeShirt is a novel ambulatory monitoring system that records cardiorespiratory measurements outside the laboratory. Validity and reliability of cardiorespiratory measurements recorded by the LifeShirt were assessed and two methods of calibrating the LifeShirt were compared. Participants performed an incremental treadmill test and a constant work rate test (65% peak oxygen uptake) on four occasions (>48 h apart) and wore the LifeShirt, COSMED system and Polar Sport Tester simultaneously. The LifeShirt was calibrated using two methods: comparison to a spirometer; and 800 ml fixed-volume bag. Ventilation, respiratory rate, expiratory time and heart rate recorded by the LifeShirt were compared to measurements recorded by laboratory equipment. Sixteen adults participated (6M:10 F); mean (SD) age 23.1 (2.9) years. Agreement between the LifeShirt and laboratory equipment was acceptable. Agreement for ventilation was improved by calibrating the LifeShirt using a spirometer. Reliability was similar for the LifeShirt and the laboratory equipment. This study suggests that the LifeShirt provides a valid and reliable method of ambulatory monitoring.

Our current position is that activity monitors such as SenseWear or ActiGraph offer informed choices to facilitate a comprehensive assessment of physical activity, and should as a minimum report on dimensions of physical activity including energy expenditure, step count and time spent in different intensities and sedentary time. The DigiWalker pedometer offers an informed choice of a comparatively inexpensive method of obtaining some measurement of physical activity. The HAES represents an informed choice of questionnaire to assess physical activity. There is insufficient data to recommend the use of one diary over another. Future research should focus on providing additional evidence of clinimetric properties of these and new physical activity assessment tools, as well as further exploring the added value of physical activity assessment in CF.

BackgroundThere are challenges for researchers and clinicians to select the most appropriate physical activity tool, and a balance between precision and feasibility is needed. Currently it is unclear which physical activity tool should be used to assess physical activity in Bronchiectasis. The aim of this research is to compare assessment methods (pedometer and IPAQ) to our criterion method (ActiGraph) for the measurement of physical activity dimensions in Bronchiectasis (BE), and to assess their feasibility and acceptability.MethodsPatients in this analysis were enrolled in a cross-sectional study. The ActiGraph and pedometer were worn for seven consecutive days and the IPAQ was completed for the same period. Statistical analyses were performed using SPSS 20 (IBM). Descriptive statistics were used; the percentage agreement between ActiGraph and the other measures were calculated using limits of agreement. Feedback about the feasibility of the activity monitors and the IPAQ was obtained.ResultsThere were 55 (22 male) data sets available. For step count there was no significant difference between the ActiGraph and Pedometer, however, total physical activity time (mins) as recorded by the ActiGraph was significantly higher than the pedometer (mean ± SD, 232 (75) vs. 63 (32)). Levels of agreement between the two devices was very good for step count (97% agreement); and variation in the levels of agreement were within accepted limits of ±2 standard deviations from the mean value.IPAQ reported more bouted- moderate - vigorous physical activity (MVPA) [mean, SD; 167(170) vs 6(9) mins/day], and significantly less sedentary time than ActiGraph [mean, SD; 362(115) vs 634(76) vmins/day]. There were low levels of agreement between the two tools (57% sedentary behaviour; 0% MVPA10+), with IPAQ under-reporting sedentary behaviour and over-reporting MVPA10+ compared to ActiGraph. The monitors were found to be feasible and acceptable by participants and researchers; while the IPAQ was accepta ble to use, most patients required assistance to complete it.ConclusionsAccurate measurement of physical activity is feasible in BE and will be valuable for future trials of therapeutic interventions. ActiGraph or pedometer could be used to measure simple daily step counts, but ActiGraph was superior as it measured intensity of physical activity and was a more precise measure of time spent walking. The IPAQ does not appear to represent an accurate measure of physical activity in this population.Trial registrationClinical Trials Registration Number NCT01569009: Physical Activity in Bronchiectasis.

Respiratory inductive plethysmography (e.g., LifeShirt) may offer in-depth study of the cardiorespiratory responses during field exercise tests. The aims of this study were to assess the reliability, discriminate validity, and responsiveness of cardiorespiratory measurements recorded by the LifeShirt during field exercise tests in adults with CF. To assess reliability and discriminate validity, participants with CF and stable lung disease and healthy participants performed the 6-Minute Walk Test (6MWT) and Modified Shuttle Test (MST) on two occasions. To assess responsiveness, participants with CF experiencing an exacerbation performed the 6MWT at the start and end of an admission for intravenous antibiotics. The LifeShirt was worn during all exercise tests. Reliability and discriminate validity were assessed in 18 participants with CF (mean (SD) age: 26 (10) years; FEV1 %predicted: 69.2 (23)%) and 18 healthy participants (age: 24 (5) years, FEV1 % predicted: 92 (8)%). There was no difference in 6MWT and MST performance between days and reliability of cardiorespiratory measures was acceptable (bias: P > 0.05; CV < 10%). Participants with CF demonstrated a significantly greater response to exercise (e.g., ventilation, respiratory rate) compared to healthy participants indicating discriminate validity. Responsiveness was assessed in 12 participants with CF: clinical measurements and 6MWT performance improved (61 (81) min; P < 0.05) however, cardiorespiratory measurements recorded by the LifeShirt remained the same (bias: P > 0.05; CV < 10%). This study provides evidence that cardiorespiratory responses can be measured non-invasively during field exercise tests in adults with CF. Reliability and discriminate validity of key cardiorespiratory measurements recorded by the LifeShirt were demonstrated. Some information on responsiveness is reported.