Six-minute walk test as a determinant of the functional capacity of children and adolescents with cystic fibrosis: A systematic review

Monitoring Activity and Gait in Children (MAGIC) using digital health technologies

BACKGROUND

Digital health technologies (DHTs) can collect gait and physical activity in adults, but limited studies have validated these in children. This study compared gait and physical activity metrics collected using DHTs to those collected by reference comparators during in-clinic sessions, to collect a normative accelerometry dataset, and to evaluate participants' comfort and their compliance in wearing the DHTs at-home.

METHODS

The MAGIC (Monitoring Activity and Gait in Children) study was an analytical validation study which enrolled 40, generally healthy participants aged 3-17 years. Gait and physical activity were collected using DHTs in a clinical setting and continuously at-home.

RESULTS

Overall good to excellent agreement was observed between gait metrics extracted with a gait algorithm from a lumbar-worn DHT compared to ground truth reference systems. Majority of participants either "agreed" or "strongly agreed" that wrist and lumbar DHTs were comfortable to wear at home, respectively, with 86% (wrist-worn DHT) and 68% (lumbar-worn DHT) wear-time compliance. Significant differences across age groups were observed in multiple gait and activity metrics obtained at home.

CONCLUSIONS

Our findings suggest that gait and physical activity data can be collected from DHTs in pediatric populations with high reliability and wear compliance, in-clinic and in home environments.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT04823650 IMPACT: Digital health technologies (DHTs) have been used to collect gait and physical activity in adult populations, but limited studies have validated these metrics in children. The MAGIC study comprehensively validates the performance and feasibility of DHT-measured gait and physical activity in the pediatric population. Our findings suggest that reliable gait and physical activity data can be collected from DHTs in pediatric populations, with both high accuracy and wear compliance both in-clinic and in home environments. The identified across-age-group differences in gait and activity measurements highlighted their potential clinical value.

The PAY test: a new approach for assessing functional performance in children and adolescents with asthma

OBJECTIVE

To develop, validate, and test the reproducibility of a new test capable of assessing functional performance in children and adolescents (PAY test: Performance Activity in Youth).

METHODS

participants without and with asthma were included in the development and validation phases, respectively. The PAY test includes five activities: transition from sitting to standing, walking 10 m, step climbing, shoulder extension and flexion, and star jumps. Participants underwent the Pediatric Glittre test (TGlittre-P test time), modified shuttle test (MST), and cardiopulmonary exercise test (CPET).

OUTCOMES

PAY test and TGlittre-P test times, oxygen uptake (VO2peak), and distance walked in the MST.

RESULTS

8 healthy volunteers, aged 12 (7 - 15) years old were included in the development phase and 34 participants with asthma, aged 11 (7 -14) years old, in the validation phase. The PAY test elicited greater physiological responses (VO2peak 33.5 ± 6.9 mL/kg) than the TGlittre-P (VO2peak: 27.4 ± 9.0 mL/kg), but lower than the MST (VO2peak: 48.9 ± 14.2 mL/kg) and CPET (VO2peak: 42.0 ± 8.8 mL/kg), p < .05. Moderate correlation between the PAY test time and the TGlittre-P time (r = 0.70, p < .001) and distance walked in the MST (r = -0.72, p < .001). The PAY test time was longer in participants with asthma than in healthy participants (3.1 [3.0 - 3.3] min vs. 2.3 [2.1 - 2.4 min]), p < .001.; and the test was reproducible (ICC 0.78, CI 95% 0.55-0.90, p < .001).

CONCLUSIONS

The PAY test is a valid and reproducible tool for assessing functional performance in children and adolescents with asthma.

Guidance and standard operating procedures for functional exercise testing in cystic fibrosis

Regular exercise testing is recommended for all people with cystic fibrosis (PwCF). A range of validated tests, which integrate both strength and aerobic function, are available and increasingly being used. Together, these tests offer the ability for comprehensive exercise evaluation. Extensive research and expert consensus over recent years has enabled the adaptation and standardisation of a range of exercise tests to aid the understanding of the pathophysiology related to exercise limitation in PwCF and has led to the development of novel exercise tests which may be applied to PwCF. This article provides expert, opinion-based clinical practice guidance, along with test instructions, for a selection of commonly used valid tests which have documented clinimetric properties for PwCF. Importantly, this document also highlights previously used tests that are no longer suggested for PwCF and areas where research is mandated. This collaboration, on behalf of the European Cystic Fibrosis Society Exercise Working Group, represents expert consensus by a multidisciplinary panel of physiotherapists, exercise scientists and clinicians and aims to improve global standardisation of functional exercise testing of PwCF. In short, the standardised use of a small selection of tests performed to a high standard is advocated.

The cardiorespiratory response and physiological determinants of the 6-min handbike cycle test in healthy children: A cross-sectional study

INTRODUCTION

The submaximal tests are used to measure aerobic capacity and correlate with activities of daily living in chronic patients. The 6-min handbike cycle test (6mhct) was created for nonambulatory subjects, but there are no reference values to quantify and classify the cardiorespiratory fitness of children in this condition.

OBJECTIVE(S)

Generate 6mhct reference values and determine predictive variables in a population of Chilean children between 8 and 13 years old.

MATERIALS AND METHODS

Cross-sectional study. Sampling for convenience, stratified by age. Evaluation of anthropometric variables, handgrip strength, heart rate (HR), effort perception, and blood pressure were performed, then the 6mhct was applied. Descriptive statistics, Student's t test and Mann-Whitney U test, correlation coefficient, and regression equation were used to estimate the total revolutions by age, being significant p < 0.05.

RESULTS

Were evaluated 120 children homogeneously distributed by age. The total revolutions performed by boys and girls were 861.4 ± 102.9 and 771.8 ± 90.2, respectively (p < 0.001). There was a significant correlation between total revolutions and age (r = .52), weight (r = .29), height (r = .46), average  UULL (length of the upper limb) length (r = .44), average handgrip strength (r = .53), peak HR (r = .67), recovery HR (r = .44), and HR reserve (r = .72). The regression equation was established.

CONCLUSIONS

These results can be used as preliminary reference values for the 6mhct in Chilean children from 8 to 13 years old. Handgrip strength, age, peak HR, and HR reserve influenced the performance of the 6mhct.

Effects of Elexacaftor/Tezacaftor/Ivacaftor on Cardiorespiratory Polygraphy Parameters and Respiratory Muscle Strength in Cystic Fibrosis Patients with Severe Lung Disease

BACKGROUND

Cystic fibrosis transmembrane conductance regulator (CFTR) modulators represent targeted therapies directly acting on the CFTR channel. The triple therapy Elexacaftor/Tezacaftor/Ivacaftor (ELX/TEZ/IVA) has been demonstrated to improve lung function and quality of life in cystic fibrosis (CF) patients. However, the effects of ELX/TEZ/IVA on sleep-disordered breathing (SDB) and respiratory muscle strength are poorly studied. The aim of this study was to assess the effects of ELX/TEZ/IVA in patients with CF and severe lung disease on cardiorespiratory polygraphy parameters, maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP) measures.

METHODS

patients with CF aged ≥ 12 who started treatment in a compassionate use program were retrospectively studied through the evaluation of nocturnal cardiorespiratory polygraphy parameters, MIP and MEP; and six-minute walk test (6MWT) at baseline and at months 3, 6, and 12 of treatment.

RESULTS

Nine patients (mean age 30.3 ± 6.5 years) with severe CF (mean baseline ppFEV1 34.6 ± 5.1%) were evaluated. A significant improvement in nocturnal oxygenation measured by mean SpO2 (92.4 vs. 96.4%, p < 0.05), time spent with SpO2 ≤ 90% (-12.6, -14.6, -15.2 min from baseline at months 3, 6, and 12, respectively, p < 0.05), and respiratory rate (RR) was shown, at month 12 and across the time points compared with baseline, as well as in respiratory muscle strength, although only the change in MEP was significant.

CONCLUSIONS

We provide further evidence on the efficacy of the CFTR modulators ELX/TEZ/IVA, adding information about their effect on the respiratory muscles' performance and cardiorespiratory polygraphy parameters in CF patients with severe lung disease.

"Just Move It . . . Move It": A Multidisciplinary Motivational Approach to Improve Physical Activity in Children With Cystic Fibrosis

Regular physical activity (PA) is essential in cystic fibrosis (CF). This study assessed the impact of a motivational interviewing (MI)-based project titled "Just move it . . . move it," aimed at improving the PA of pediatric CF patients. At baseline and month 6, body mass index, spirometric values, and duration of extracurricular sport activities were collected. Concurrently, the maximum oxygen uptake (VO2max) was estimated. MI was performed during each visit. Overall, 19 CF children were included. Ten patients (52.7%) increased their regular PA (mean 1.9 hours/week) between both visits (PA+ group), while 9 did not (PA- group). No significant differences in functional and nutritional values were observed between the groups, while extracurricular sport time significantly increased in the PA+ group. "Just move it . . . move it" seems to be an efficient approach, as it was able to motivate several CF patients to initiate or increase their PA, yet without improving functional parameters.

Six-minute walk test and factors affecting exercise capacity in children with cystic fibrosis

PURPOSE

This study aimed to compare the result of the six-minute walk test (6MWT) in patients with cystic fibrosis (CF) aged < 20 years old and individuals without CF.

METHODS

In this cross-sectional study, 50 children and adolescents with CF and 20 children and adolescents without CF underwent the 6MWT. Vital signs before and immediately after the 6MWT and six-minute walk distance (6MWD) were evaluated.

RESULTS

The mean change in heart rate, percentage of peripheral oxygen saturation (SpO2%), systolic blood pressure, respiratory rate, and dyspnea severity during the 6MWT was significantly higher in patients with CF. In the case group, 6MWD was associated with regular chest physical therapy (CPT) and forced expiratory volume (FEV)> 80%. Patients with CF receiving regular CPT or mechanical vibration and with FEV in the first second > 80% showed better physical capacity during the 6MWT (smaller Sp02% decline and lower dyspnea perception).

CONCLUSION

Children and adolescents with CF have lower physical capacity compared to individuals without CF. CPT and mechanical vibration could be used to increase physical capacity in this population.

Is the six-minute walk test still reliable compared to cardiopulmonary exercise test for exercise capacity in children with congenital heart disease?

OBJECTIVES

We aimed to assess the validity of the six-minute walk test (6MWT) to reflect the functional capacity of children with congenital heart disease (CHD), evaluate a possible correlation between the 6MWT distance with cardiopulmonary exercise test (CPET) variables, as well as to find a cutoff value to stratification the physical fitness in this population.

METHODS

We enrolled 459 children with CHD, 6-18 years old, who performed a complete CPET and 6MWT on the same day in a cross-sectional observational study. Correlations between variables of CPET and six-minute walking distance (6MWD) were analyzed and cutoff values of 6MWD were identified for the classification of the physical fitness in the population.

RESULTS

The mean distance ambulated during the 6MWT was 578 ± 65 m, 590 ± 65 m for boys, and 562 ± 62 m for girls (p < 0.001). Both VO_2max and %predicted VO_2max showed a correlation with the 6MWT distance (r = 0.35, p < 0.001 and r = 0.51, p < 0.001, respectively), and an inverse correlation was found between VE/VCO2 slope and the 6MWT distance (r = -0.31; p < 0.001). There appeared to be a linear association between 6MWD and VO_2max up to a 6MWD of approximately 600 m. We divided the population into 4 subgroups (boys <130 cm; boys ≥130 cm; girls <130 cm; girls ≥130 cm), and get the cutoff values (554 m, 617 m, 549 m, 587 m) respectively equivalent to 80% of predicted VO_2max. The 6MWT distances of another 102 patients were applied for external verification of the cutoff values.

CONCLUSIONS

Our study provided evidence on when a 6MWT should be considered as a convincing complementary test in the pediatric population with CHD and explored the classification of exercise tolerance using a 6MWD value. The cut-off values for 6MWD may be qualified as an intervention target for exercise rehabilitation.

Quality of life and exercise tolerance tools in children/adolescents with cystic fibrosis: Systematic review

INTRODUCTION

This systematic review aims to analyze the validity and reliability of available tools to assess health-related quality of life (HRQoL) and exercise tolerance in children and adolescents with cystic fibrosis (CF).

MATERIALS AND METHODS

A review of observational studies studying the validity and reliability of the tools was conducted. The COSMIN (COnsesus-based Standards for the selection of health Measurements INstruments) guide was followed to analyze the quality of these tools.

RESULTS

A total of 18 studies were selected. Of the eight HRQoL tools, five generic and three specific, analyzed in 14 studies, the Cystic Fibrosis Questionnaire-Revised (CFQ-R) presents the best properties. Of the four tools analyzed to assess exercise tolerance, cycle ergometry and the modified shuttle test are the most valid and reliable.

CONCLUSIONS

The CFQ-R, cycloergometry and the modified shuttle test have the best properties for the assessment of children with CF, but more studies are needed.

Relationship between peripheral muscle strength, exercise capacity and body composition in children and adolescents with cystic fibrosis

STUDY DESIGN

This was a transversal analytical study.

BACKGROUND

Exercise capacity is usually decreased in cystic fibrosis, impacting the disease prognosis. As well, peripheral muscle strength and nutritional status seem to be related to exercise capacity (EC).

OBJECTIVE

To verify the relationship between peripheral muscle strength, pulmonary function and body composition with EC in children and adolescents with CF.

METHODS

The study included CF children/adolescents that were clinically stable. The disease's severity was classified according to the Schwachman-Doerschuk score. Initially the subjects underwent bioimpedance and spirometry tests. Quadriceps muscle strength (QMS) and handgrip strength (HG) were evaluated by dynamometry. The Modified Shuttle Walk Test (MSWT) was conducted along with gas analysis in order to measure EC.

RESULTS

Twenty-five children/adolescents (10.30 ± 2.33 years old) participated in the survey. 72% were eutrophic, with a mean FEV1 of 68.55%, predicted percentage of the MSWT walked distance (%WD) was 70.91%, and QMS 65.80%. QMS presented significant correlations with absolute WD (r = 0.54), oxygen peak consumption (r = 0.72), lean body mass (LM) (r = 0.83), and body mass index (BMI) (r = 0.69). HG was related with BMI (r = 0.45) and LM (r = 0.65). There was a difference in the %WD between the groups with higher/lower strength (p = .02).

CONCLUSION

There was no correlation between HG and EC in this studied sample. Early involvement of QMS was observed even in individuals with low disease severity. This finding reinforces the importance of including this QMS assessment in CF reference centers to monitor, prevent and prescribe adequate exercise training for these individuals.

Functional respiratory imaging in relation to classical outcome measures in cystic fibrosis: a cross-sectional study

Background

Functional Respiratory Imaging (FRI) combines HRCT scans with computational fluid dynamics to provide objective and quantitative information about lung structure and function. FRI has proven its value in pulmonary diseases such as COPD and asthma, but limited studies have focused on cystic fibrosis (CF). This study aims to investigate the relation of multiple FRI parameters to validated imaging parameters and classical respiratory outcomes in a CF population.

Methods

CF patients aged > 5 years scheduled for a chest CT were recruited in a cross-sectional study. FRI outcomes included regional airway volume, airway wall volume, airway resistance, lobar volume, air trapping and pulmonary blood distribution. Besides FRI, CT scans were independently evaluated by 2 readers using the CF-CT score. Spirometry and the 6-Minute Walk Test (6MWT) were also performed. Statistical tests included linear mixed-effects models, repeated measures correlations, Pearson and Spearman correlations.

Results

39 CT scans of 24 (17M/7F) subjects were analyzed. Patients were 24 ± 9 years old and had a ppFEV₁ of 71 ± 25% at the time of the first CT. All FRI parameters showed significant low-to-moderate correlations with the total CF-CT score, except for lobar volume. When considering the relation between FRI parameters and similar CF-CT subscores, significant correlations were found between parameters related to airway volume, air trapping and airway wall thickening. Air trapping, lobar volume after normal expiration and pulmonary blood distribution showed significant associations with all spirometric parameters and oxygen saturation at the end of 6MWT. In addition, air trapping was the only parameter related to the distance covered during 6MWT. A subgroup analysis showed considerably higher correlations in patients with mild lung disease (ppFEV₁ ≥ 70%) compared to patients with moderate to severe lung disease (ppFEV₁ < 70%) when comparing FRI to CF-CT scores.

Conclusions

Multiple structural characteristics determined by FRI were associated with abnormalities determined by CF-CT score. Air trapping and pulmonary blood distribution appeared to be the most clinically relevant FRI parameters for CF patients due to their associations with classical outcome measures. The FRI methodology could particularly be of interest for patients with mild lung disease, although this should be confirmed in future research.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01622-3.

The measurement properties of tests and tools used in cystic fibrosis studies: a systematic review

There is no consensus on how best to measure responses to interventions among children and adults with cystic fibrosis (CF). We have systematically reviewed and summarised the characteristics and measurement properties of tests and tools that have been used to capture outcomes in studies among people with CF, including their reliability, validity and responsiveness. This review is intended to guide researchers when selecting tests or tools for measuring treatment effects in CF trials. A consensus set of these tests and tools could improve consistency in how outcomes are captured and thereby facilitate comparisons and synthesis of evidence across studies.

The Fitter the Better? Cardiopulmonary Exercise Testing Can Predict Pulmonary Exacerbations in Cystic Fibrosis

Background: The role of cardiopulmonary exercise testing (CPET) in the assessment of prognosis in CF (cystic fibrosis) is crucial. However, as the overall survival of the disease becomes better, the need for examinations that can predict pulmonary exacerbations (PEx) and subsequent deterioration becomes evident. Methods: Data from a 10-year follow up with CPET and spirometry of CF patients were used to evaluate whether CPET-derived parameters can be used as prognostic indexes for pulmonary exacerbations in patients with CF. Pulmonary exacerbations were recorded. We used a survival analysis through Cox Regression to assess the prognostic role of CPET parameters for PeX. CPET parameters and other variables such as sputum culture, age, and spirometry measurements were tested via multivariate cox models. Results: During a 10-year period (2009–2019), 78 CF patients underwent CPET. Cox regression analysis revealed that VO₂peak% (peak Oxygen Uptake predicted %) predicted (hazard ratio (HR), 0.988 (0.975, 1.000) p = 0.042) and PetCO₂ (end-tidal CO₂ at peak exercise) (HR 0.948 (0.913, 0.984) p = 0.005), while VE/VO₂ and (respiratory equivalent for oxygen at peak exercise) (HR 1.032 (1.003, 1.062) p = 0.033) were significant predictors of pulmonary exacerbations in the short term after the CPET. Additionally, patients with VO₂peak% predicted <60% had 4.5-times higher relative risk of having a PEx than those with higher exercise capacity. Conclusions: CPET can provide valuable information regarding upcoming pulmonary exacerbation in CF. Patients with VO₂peak <60% are at great risk of subsequent deterioration. Regular follow up of CF patients with exercise testing can highlight their clinical image and direct therapeutic interventions.

Capacidade de exercício e nível de atividade física diária de crianças e adolescentes com fibrose cística: associação com estado nutricional, função pulmonar, hospitalização e uso de antibióticos

RESUMO O objetivo deste trabalho é avaliar a capacidade de exercício e nível de atividade física diária de crianças e adolescentes com fibrose cística e associar com estado nutricional, função pulmonar, tempo de hospitalização e uso de antibióticos. Trata-se de estudo transversal em indivíduos com fibrose cística entre 6 e 18 anos, registrando-se informações sobre perfil clínico, histórico de hospitalizações e uso de antibióticos. Os participantes foram submetidos à espirometria, bioimpedância, avaliação da capacidade de exercício com teste de Shuttle modificado (MST), o nível da atividade física foi medido por meio do questionário internacional de atividade física (IPAQ) e usando acelerômetro por 5 dias. Participaram 30 indivíduos com idade de 11,2 ± 3,6 anos e volume expirado forçado (VEF1) de 68,0 ± 24,8%. A mediana da distância percorrida no MST foi de 820 metros (66,3%) e demonstrou associação com a função pulmonar (r = 0,78), estado nutricional (r = 0,38), tempo de hospitalização (r = -0,42) e uso de antibióticos (r = -0,46). De acordo com o questionário, 20 pacientes (64,6%) foram classificados como sedentários, o acelerômetro revelou que os indivíduos passam 354,2 minutos em atividades sedentárias e apenas 14,9 minutos em atividades moderadas a vigorosas por dia. Quanto maior a porcentagem de tempo em atividade física moderada a vigorosa, maior o índice de massa corpórea (IMC) e menor o tempo de hospitalização. Assim, a capacidade de exercício e nível de atividade física em crianças e adolescentes com fibrose cística apresentou-se reduzida e associada com menores valores de IMC e aumento do tempo de hospitalização.

A short-term evaluation of a prototype disposable Oscillating Positive Expiratory Pressure (OPEP) device in a cohort of children with cystic fibrosis

Background

Oscillating Positive Expiratory Pressure (OPEP) devices are important adjuncts to airway clearance therapy in patients with cystic fibrosis (CF). Current devices are typically reusable and require daily, or often more frequent, cleaning to prevent risk of infection by acting as reservoirs of potentially pathogenic organisms. In response, a daily disposable OPEP device, the UL-OPEP, was developed to mitigate the risk of contamination and eliminate the burdensome need for cleaning devices.

Methods

A convenience sample of 36 participants, all current OPEP device users, was recruited from a paediatric CF service. For one month, participants replaced their current OPEP device with a novel daily disposable device. Assessment included pre- and post-intervention lung function by spirometry, as well as Lung Clearance Index. Quality of life was assessed using the Cystic Fibrosis Questionnaire – Revised, while user experience was evaluated with a post-study survey.

Results

31 participants completed the study: 18 males; median age 10 years, range 4–16 years. Lung function (mean difference ± SD, %FEV1 = 1.69 ± 11.93; %FVC = 0.58 ± 10.04; FEV1: FVC = 0.01 ± 0.09), LCI (mean difference ± SD, 0.08 ± 1.13), six-minute walk test, and CFQ-R were unchanged post-intervention. Participant-reported experiences of the device were predominantly positive.

Conclusions

The disposable OPEP device maintained patients’ lung function during short term use (≤ 1 month), and was the subject of positive feedback regarding functionality while reducing the risk of airway contamination associated with ineffective cleaning.

Registration

The study was approved as a Clinical Investigation by the Irish Health Products Regulatory Authority (CRN-2209025-CI0085).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01525-3.

Measurement properties of the one-minute sit-to-stand test in children and adolescents with cystic fibrosis: A multicenter randomized cross-over trial

Background

Functional exercise capacity assessment is recommended in children with cystic fibrosis (CF). The six-minute walk test (6MWT) is a valid evaluation of exercise capacity but can be technically complex. Inversely, the sit-to-stand test (STST) is a simple method to evaluate exercise capacity, and is validated in healthy children and adults with CF. This study aimed to evaluate STST measurement properties in children and adolescents with CF.

Methods

In this multicenter study, children with CF (6 to 18 years) performed two iterations of both the STST and the 6MWT in a randomized order. Criterion validity was determined by assessing correlations between STST repetitions and 6MWT distance (6MWD). Intra-rater reliability, test-retest repeatability, mean bias and limits of agreement were also assessed. Relationships with other outcomes (i.e. respiratory and quadriceps muscle strength) and cardio-respiratory responses were analysed for both tests.

Results

Thirty-six children with CF were included (mean age 12.0 ±3.5 years and FEV1 95.8 ±25.0%). On average, 39.6 ±10.5 repetitions were performed during the STST and mean 6MWD was 596.0 ±102.6 meters. STST number of repetitions was significantly correlated with 6MWD (r = 0.48; p<0.01). Both tests had very good intra-rater reliability (ICC_STST = 0.91 (95%CI 0.76–0.96) and ICC_6MWT = 0.94 (95%CI 0.85–0.97)), and a significant test-retest learning effect. The number of STST repetitions was not correlated with quadriceps or respiratory muscle strength test, and the STST induced fewer cardio-respiratory responses than the 6MWT.

Conclusions

The STST is an easy-to-use functional test with moderate criterion validity when compared to the 6MWT in children with CF, probably because both tests measure different components of functional exercise capacity. The STST is useful when the 6MWT is unfeasible, however further investigations are required to explore the clinical implications of STST results in children with CF.

Clinical trial registration

NCT03069625.

Systematic review of clinical effectiveness, components, and delivery of pulmonary rehabilitation in low-resource settings

Pulmonary rehabilitation (PR) is a guideline-recommended multifaceted intervention that improves the physical and psychological well-being of people with chronic respiratory diseases (CRDs), though most of the evidence derives from trials in high-resource settings. In low- and middle-income countries, PR services are under-provided. We aimed to review the effectiveness, components and mode of delivery of PR in low-resource settings. Following Cochrane methodology, we systematically searched (1990 to October 2018; pre-publication update March 2020) MEDLINE, EMBASE, CABI, AMED, PUBMED, and CENTRAL for controlled clinical trials of adults with CRD (including but not restricted to chronic obstructive pulmonary disease) comparing PR with usual care in low-resource settings. After duplicate selection, we extracted data on exercise tolerance, health-related quality of life (HRQoL), breathlessness, included components, and mode of delivery. We used Cochrane risk of bias (RoB) to assess study quality and synthesised data narratively. From 8912 hits, we included 13 studies: 11 were at high RoB; 2 at moderate RoB. PR improved functional exercise capacity in 10 studies, HRQoL in 12, and breathlessness in 9 studies. One of the two studies at moderate RoB showed no benefit. All programmes included exercise training; most provided education, chest physiotherapy, and breathing exercises. Low cost services, adapted to the setting, used limited equipment and typically combined outpatient/centre delivery with a home/community-based service. Multicomponent PR programmes can be delivered in low-resource settings, employing a range of modes of delivery. There is a need for a high-quality trial to confirm the positive findings of these high/moderate RoB studies.

REPRODUCIBILITY OF PHYSIOLOGICAL VARIABLES OF THE SIX-MINUTE WALK TEST IN HEALTHY STUDENTS

OBJECTIVE

To verify the reproducibility of the six-minute walk test (6MWT) performance and its physiological variables in healthy students.

METHODS

This is as prospective cross-sectional study. The sample consisted of healthy students aged 6-12 years old from public and private schools in the region of Florianópolis City, Santa Catarina State, (Southern Brazil). The medical state was considered according to the health records and scores on the International Study of Asthma and Allergies in Childhood (ISAAC) and the spirometric values of forced expiratory volume in the first second and forced vital capacity above 80% of what was predicted. Two 6MWTs were conducted with a 30-minute interval between them, following the recommendations from the American Thoracic Society. Physiologic variables were recorded using the portable telemetric gas analyzer K4b2 (Cosmed®, Italy). For analysis, the dyspnea index, the perception of effort and performance variables identified in both 6MWT were considered. Data distribution was verified with the Shapiro-Wilk test and statistical analysis included paired t-test or Wilcoxon test, and intraclass correlation coefficient (ICC). The significance level adopted was 5%.

RESULTS

A total of 22 students with a mean age of 10.2±1.5 years participated in the study. The covered distance and the variation of oxygen consumption reproducibility between the two 6MWTs presented ICC=0.76 and ICC=0.86, respectively. There was also similar behavior of the physiological variables when comparing the two tests (p=0.001), especially the minute volume (MV), the oxygen consumption (VO2), and the carbon dioxide production (VCO2).

CONCLUSIONS

The 6MWT showed reproducible values, both in performance and physiological parameters, in the healthy students analyzed.

Outcome measures for airway clearance techniques in children with chronic obstructive lung diseases: a systematic review

BACKGROUND

Airway clearance techniques (ACTs) are an important aspect of the treatment of children with chronic obstructive lung diseases. Unfortunately, a sound evidence base is lacking and airway clearance strategies are largely based on clinical expertise. One of the reasons for the limited evidence is the lack of appropriate outcome measures specifically related to the effectiveness of ACTs. This review discusses all outcome measures applied in previous research in the pediatric population to provide a baseline for future studies.

DATA SOURCES

A systematic literature search was performed in PubMed, Web of Science and EMBASE databases. Search terms included chronic obstructive lung diseases and ACTs.

STUDY SELECTION

Studies were independently selected by the investigators according to the eligibility criteria. After screening, 49 articles remained for further analysis.

RESULTS AND CONCLUSIONS

Data are summarized according to the type of outcome measure. 48 (98%) studies performed pulmonary function tests, 19 (39%) assessed expectorated sputum, 10 (20%) parameters related to disease exacerbation, 8 (16%) oxygenation, 8 (16%) patient-reported outcomes, 5 (10%) exercise capacity and 5 (10%) applied imaging techniques. The synthesis of results showed a high discrepancy between studies due to differences in study design, population and the application of techniques. Since no 'gold standard' method could be identified, a combination of different outcome measures is recommended to gain a better understanding and to identify the potential effects of ACTs. An overview of important considerations has been provided to assist researchers in their choice of outcomes in future studies.

Exercise testing for children with cystic fibrosis: A systematic review

BACKGROUND

Exercise testing is routinely used to measure exercise capacity in children with cystic fibrosis (CF). Various tests are available, however the psychometric properties of these measures have not been systematically reviewed for this population.

METHOD

A systematic search of electronic databases (PubMed, Web of Science, Medline, CINHAL, Cochrane, and PEDro) was performed to identify papers that: (a) reported original psychometric data, (b) examined a measure of exercise capacity, (c) examined children with CF aged eight to 18 years; and (d) were published in English after 1950. The level of psychometric evidence was evaluated using the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) checklist.

RESULTS

Searches identified 1025 papers. Forty-six papers were included, covering 15 tests: incremental cardiopulmonary exercise test using a cycle ergometer (CPET(cycle)) or treadmill (CPET(treadmill)), 6 minute walk test (6MWT), modified shuttle test (MST), 3-minute step test (3MST), 2 minute walk test (2MWT), Bratteby walk test, intermittent sprint test, speed ramp test, incremental step test, forward-backwards jump test (FBJT), astride jump test (AJT), motor quotient test, Munich fitness test, and Glittre ADL test.

CONCLUSION

There is a plethora of exercise tests available with varying psychometric robustness. The CPET, 6MWT, and MST have fair to good psychometric properties, but each with their clinical advantages and limitations. Thus, a Selection Guide was developed to assist clinicians and researchers in selecting the most appropriate exercise test for various situations.

Does Ramadan Observance Affect Cardiorespiratory Capacity of Healthy Boys?

Studies raising the issue of the effects of Ramadan observance (RO) on boys' 6-min walk test (6MWT) data are rare. The studies, which did not include control groups of non-fasters, presented contradictory results. This study aimed to compare the 6MWT data (6-min walk distance [6MWD; m, %predicted], heart rate [HR; bpm, % of maximal predicted HR]), oxy-hemoglobin saturation (Oxy-sat; %), systolic and diastolic blood pressures (SBP and DBP, respectively; mmHg) determined at rest (_Rest and at the end _End of the test) of a group of 22 healthy fasting boys (age: 12 to 15 years) with an age-matched non-fasting group (n = 10). The 6MWTs were performed during three experimental conditions (ECs): Pre-Ramadan, Mid-Ramadan, and Post-Ramadan. The two groups' 6MWT data for each EC were compared, and repeated factorial analysis of variance (2 groups vs. 3 ECs) was performed. Both groups had similar values of 6MWD (m, %predicted), HR_Rest or HR_End (bpm, % of maximal predicted HR), Oxy-sat_Rest, Oxy-sat_End, SBP_Rest, and DBP_Rest during the three ECs. Compared to the non-fasting group, the fasting group had significantly higher SBP_End (121 ± 10 vs. 130 ± 11) and DBP_End (72 ± 6 vs. 78 ± 7) determined during the Mid-Ramadan EC. No significant interactive effects of the groups (2) vs. ECs (3) was found for the 6MWD (%predicted; p = .809), HR_Rest (%, p = .555), HR_End (%, p = .964), Oxy-sat_Rest (p = .336), Oxy-sat_End (p = .389), SBP_Rest (p = .708), SBP_End (p = .548), DBP_Rest (p = .277), and DBP_End (p = .096). To conclude, in boys, RO does not impact the 6MWD, HR, or Oxy-sat, but it has minimal impact on the SBP_End and DBP_End.

Valores médios percorridos no teste de caminhada de seis minutos em crianças saudáveis de Coari (AM)

RESUMO O objetivo desta pesquisa foi estabelecer valores médios percorridos para o teste de caminhada de seis minutos em crianças saudáveis no Norte do Brasil. Este foi um estudo experimental, randomizado, cego e transversal que avaliou 63 crianças saudáveis do sexo masculino e feminino, de 10 a 12 anos, que após terem seus dados antropométricos registrados foram treinadas e instruídas para a realização do teste conforme recomendações da American Thoracic Society, após avaliação-padrão. O teste foi realizado numa pista reta de 30 metros, com marcações a cada 3 metros e cones indicando onde o retorno deveria ser feito para a continuidade do teste. Ao final, foi refeita a avaliação pré-teste. Foi observado índice de massa corporal muito baixo nos meninos de 11 anos, e normal nas outras faixas. A frequência cardíaca imediata pós-teste apresentou-se significativamente elevada em todos os grupos (p<0,001), enquanto todos os outros dados cardiovasculares colhidos não apresentaram alterações. As distâncias percorridas foram significativamente inferiores às previstas por equação-padrão para todos os grupos e sexos (p<0,0001). O valor médio percorrido encontrado em meninas foi de 436,30±56,74m e 460,80±63,90m em meninos, enquanto a média geral foi de 445,70±54,10m, abaixo dos valores esperados para a amostra. O resultado obtido pelo grupo estudado, menor que a média esperada, pode ser creditado ao fenótipo regional, mas o Índice de Desenvolvimento muito mais baixo que a média brasileira deve ter sua influência mais bem estudada. Espera-se que os achados contribuam no apontamento de valores de referência do teste em crianças do Norte brasileiro.