Nidia A. Hernandes

An official European Respiratory Society/American Thoracic Society technical standard: field walking tests in chronic respiratory disease

Field walking tests are commonly employed to evaluate exercise capacity, assess prognosis and evaluate treatment response in chronic respiratory diseases. In recent years, there has been a wealth of new literature pertinent to the conduct of the 6-min walk test (6MWT), and a growing evidence base describing the incremental and endurance shuttle walk tests (ISWT and ESWT, respectively). The aim of this document is to describe the standard operating procedures for the 6MWT, ISWT and ESWT, which can be consistently employed by clinicians and researchers. The Technical Standard was developed by a multidisciplinary and international group of clinicians and researchers with expertise in the application of field walking tests. The procedures are underpinned by a concurrent systematic review of literature relevant to measurement properties and test conduct in adults with chronic respiratory disease. Current data confirm that the 6MWT, ISWT and ESWT are valid, reliable and responsive to change with some interventions. However, results are sensitive to small changes in methodology. It is important that two tests are conducted for the 6MWT and ISWT. This Technical Standard for field walking tests reflects current evidence regarding procedures that should be used to achieve robust results. Technical Standard document: standard operating procedures for the 6MWT, ISWT and ESWT in chronic respiratory disease http://ow.ly/Bq2B9

An official systematic review of the European Respiratory Society/American Thoracic Society: measurement properties of field walking tests in chronic respiratory disease

This systematic review examined the measurement properties of the 6-min walk test (6MWT), incremental shuttle walk test (ISWT) and endurance shuttle walk test (ESWT) in adults with chronic respiratory disease. Studies that report the evaluation or use of the 6MWT, ISWT or ESWT were included. We searched electronic databases for studies published between January 2000 and September 2013. The 6-min walking distance (6MWD) is a reliable measure (intra-class correlation coefficients ranged from 0.82 to 0.99 in seven studies). There is a learning effect, with greater distance walked on the second test (pooled mean improvement of 26 m in 13 studies). Reliability was similar for ISWT and ESWT, with a learning effect also evident for ISWT (pooled mean improvement of 20 m in six studies). The 6MWD correlates more strongly with peak work capacity (r=0.59–0.93) and physical activity (r=0.40–0.85) than with respiratory function (r=0.10–0.59). Methodological factors affecting 6MWD include track length, encouragement, supplemental oxygen and walking aids. Supplemental oxygen also affects ISWT and ESWT performance. Responsiveness was moderate to high for all tests, with greater responsiveness to interventions that included exercise training. The findings of this review demonstrate that the 6MWT, ISWT and ESWT are robust tests of functional exercise capacity in adults with chronic respiratory disease. Systematic review: support for use of the 6MWT, ISWT and ESWT in adults with chronic respiratory disease http://ow.ly/Bq2Mz

Perfil do nível de atividade física na vida diária de pacientes portadores de DPOC no Brasil

OBJECTIVE: To evaluate characteristics of physical activities in daily life in COPD patients in Brazil, correlating those characteristics with physiological variables. METHODS: Physical activities in daily life were evaluated in 40 COPD patients (18 males; 66 ± 8 years of age; FEV1 = 46 ± 16 % of predicted; body mass index = 27 ± 6 kg/m2) and 30 healthy age- and gender-matched subjects, using a multiaxial accelerometer-based sensor for 12 h/day on two consecutive days. We also assessed maximal and functional exercise capacity, using the incremental exercise test and the six-minute walk test (6MWT), respectively; MIP and MEP; peripheral muscle force, using the one-repetition maximum test and the handgrip test; quality of life, using the Saint Georges Respiratory Questionnaire (SGRQ); functional status, using the London Chest Activity of Daily Living questionnaire; and dyspnea sensation, using the Medical Research Council (MRC) scale. RESULTS: Mean walking time/day was shorter for COPD patients than for the controls (55 ± 33 vs. 80 ± 28 min/day; p = 0.001), as movement intensity was lower (1.9 ± 0.4 vs. 2.3 ± 0.6 m/s2; p = 0.004). The COPD patients also tended to spend more time seated (294 ± 114 vs. 246 ± 122 min/day, p = 0.08). Walking time/day correlated with the 6MWT (r = 0.42; p = 0.007) and maximal workload (r = 0.41; p = 0.009), as well as with age, MRC scale score and SGRQ activity domain score (-0.31 < r < -0.43; p < 0.05 for all). CONCLUSIONS: This sample of Brazilian patients with COPD, although more active than those evaluated in studies conducted in Europe, were less active than were the controls. Walking time/day correlated only moderately with maximal and functional exercise capacity.

Reference equations for the six-minute walk distance based on a Brazilian multicenter study

Background It is important to include large sample sizes and different factors that influence the six-minute walking distance (6MWD) in order to propose reference equations for the six-minute walking test (6MWT). Objective To evaluate the influence of anthropometric, demographic, and physiologic variables on the 6MWD of healthy subjects from different regions of Brazil to establish a reference equation for the Brazilian population. Method In a multicenter study, 617 healthy subjects performed two 6MWTs and had their weight, height, and body mass index (BMI) measured, as well as their physiologic responses to the test. Delta heart rate (∆HR), perceived effort, and peripheral oxygen saturation were calculated by the difference between the respective values at the end of the test minus the baseline value. Results Walking distance averaged 586±106m, 54m greater in male compared to female subjects (p<0.001). No differences were observed among the 6MWD from different regions. The quadratic regression analysis considering only anthropometric and demographic data explained 46% of the variability in the 6MWT (p<0.001) and derived the equation: 6MWDpred=890.46-(6.11×age)+(0.0345×age2)+(48.87×gender)-(4.87×BMI). A second model of stepwise multiple regression including ∆HR explained 62% of the variability (p<0.0001) and derived the equation: 6MWDpred=356.658-(2.303×age)+(36.648×gender)+(1.704×height)+(1.365×∆HR). Conclusion The equations proposed in this study, especially the second one, seem adequate to accurately predict the 6MWD for Brazilians.

Comparison of daily physical activity between COPD patients from Central Europe and South America

BACKGROUND In healthy elderly and adults, lower physical activity level in daily life has been associated with lower socio-economic level and non-Caucasian race. The objective of this study was to determine if this is also applicable in chronic obstructive pulmonary disease (COPD) by comparing physical activity levels in daily life in stable patients from two countries (Austria and Brazil) with different socio-economic and ethnic characteristics. METHODS Physical activity in daily life was objectively assessed in 40 Austrian and 40 Brazilian COPD patients. Groups were matched for age, gender, body mass index, disease severity, smoking history, presence of concomitant heart disease, lung function, dyspnea and functional exercise capacity. In addition, climatic conditions were similar during the period of data collection in the two groups. RESULTS In comparison to Brazilian patients, Austrian patients had a significantly lower walking time (p=0.04), higher sitting time (p=0.02) and lower movement intensity (p=0.0001). The proportion of patients who did not reach an average of 30min of walking per day was 48% in the Austrian group and 23% in the Brazilian group. CONCLUSIONS Austrian patients with COPD showed a significantly lower daily physical activity level in comparison to matched Brazilian patients. Socio-economic and ethnic factors appear to influence stable COPD patients differently than described in previous studies including healthy subjects.

Effects of 2 Exercise Training Programs on Physical Activity in Daily Life in Patients With COPD

BACKGROUND: The effects of different exercise training programs on the level of physical activity in daily life in patients with COPD remain to be investigated. OBJECTIVE: In patients with COPD we compared the effects of 2 exercise/training regimens (a high-intensity whole-body endurance-and-strength program, and a low-intensity calisthenics-and-breathing-exercises program) on physical activity in daily life, exercise capacity, muscle force, health-related quality of life, and functional status. METHODS: We randomized 40 patients with COPD to perform either endurance-and-strength training (no. = 20, mean ± SD FEV1 40 ± 13% of predicted) at 60–75% of maximum capacity, or calisthenics-and-breathing-exercises training (no. = 20, mean ± SD FEV1 39 ± 14% of predicted). Both groups underwent 3 sessions per week for 12 weeks. Before and after the training programs the patients underwent activity monitoring with motion sensors, incremental cycle-ergometry, 6-min walk test, and peripheral-muscle-force test, and responded to questionnaires on health-related quality of life and functional status (activities of daily living, pulmonary functional status, and dyspnea). RESULTS: Time spent active and energy expenditure in daily life were not significantly altered in either group. Exercise capacity and muscle force significantly improved only in the endurance-and-strength group. Health-related quality of life and functional status improved significantly in both groups. CONCLUSIONS: Neither training program significantly improved time spent active or energy expenditure in daily life. The training regimens similarly improved quality of life and functional status. Exercise capacity and muscle force significantly improved only in the high-intensity endurance-and-strength group.

Physical activity in daily life in physically independent elderly participating in community-based exercise program

BACKGROUND It is unclear whether participation in exercise programs specifically developed for elderly translates into a more active lifestyle. OBJECTIVES To compare the objectively measured level of physical activity in daily life (PADL) between physically independent elderly who participate or do not participate in community-based exercise programs; and to evaluate which factors are associated with the higher level of PADL in these subjects. METHOD 134 elderly participants in community-based exercise programs (PG) and 104 non-participants (NPG) had their level of PADL measured using pedometers during 7 days. OTHER MEASUREMENTS 6-minute walking test (6MWT), incremental shuttle walking test (ISWT), muscle strength, flexibility and balance. RESULTS The PG had higher 1-week mean daily step count than NPG (8314 [IQR 5971-10060] vs. 6250 [IQR 4346-8207] steps/day, p<0.0001), as well as higher step count in any day of the week. There was a higher proportion of physically active subjects (>8000 steps/day) in PG than in NPG (37% vs. 16%, respectively; p<0.001), as well as the proportion of sedentary subjects (<5000 steps/day) (14% vs. 33%, respectively; p<0.001). Participation in exercise programs, 6MWT and ISWT explained a higher daily steps count (model r(2)=0.56, p<0.0001). CONCLUSIONS In physically independent elderly, a higher level of physical activity in daily life occurs in those who participate in community-based exercise programs, regardless of the weekday and including non-program days. Participation of elderly in community-based exercise programs should be more systematically available and encouraged due to its close link to higher activity levels and better exercise capacity.

Simple Lower Limb Functional Tests in Patients With Chronic Obstructive Pulmonary Disease: A Systematic Review

OBJECTIVES To evaluate the characteristics and available evidence on the measurement properties of the gait speed (GS) test, timed Up and Go test (TUG), sit-to-stand (STS) test, and step test; to investigate their relation with clinical outcomes in chronic obstructive pulmonary disease (COPD); and to provide recommendations for clinical practice and future research. DATA SOURCES Studies were systematically identified from a literature search using PubMed, PEDro, CINAHL, and Cochrane Library databases and the reference lists of the included articles. STUDY SELECTION Studies including ≥1 of these 4 lower limb functional tests (GS test, TUG, STS test, and step test) as an outcome in patients with COPD were selected. No limits were applied for language and study design. DATA EXTRACTION Two researchers independently performed data extraction and, by using the COnsensus-based standards for the Selection of health status measurement INstruments, assessed the quality of those studies that described measurement properties. DATA SYNTHESIS Forty-two articles met the selection criteria. GS test, STS test, and step test are valid, reproducible, and responsive tests, especially the 4-meter GS, 5-repetition STS test, and 6-minute step test (6MST). The TUG is reliable; however, studies on other measurement properties of this test are lacking. Outcomes of these tests are correlated with mortality, physical activity in daily life, exercise capacity, dyspnea, and quality of life. CONCLUSIONS Simple and functional lower limb tests provide information about important clinical outcomes in patients with COPD. The 4-meter GS, 5-repetition STS test, and 6MST are tests with well-established psychometric properties, whereas the properties of the TUG need to be studied further.

Evaluation of a New Motion Sensor in Patients With Chronic Obstructive Pulmonary Disease

OBJECTIVE To assess the criterion validity and reproducibility of a new pedometer in patients with chronic obstructive pulmonary disease (COPD). DESIGN Cross-sectional study. SETTING Outpatient physiotherapy clinic from a university hospital. PARTICIPANTS Patients with COPD (N=30; 17 men; forced expiratory volume in the first second, 44±17% predicted) were videotaped while performing 2 protocols: one including 2 slow and 2 fast 5-minute walks, and another including a circuit of activities of daily living (ADLs). Concomitantly, patients wore 2 motion sensors: the new pedometer and a multisensor accelerometer. INTERVENTIONS None. MAIN OUTCOME MEASURES Step counting (SC), energy expenditure (EE), walking distance (WD), activity time (AT), and walking intensity (WI) registered by the pedometer were compared with video and the multisensor as criterion methods. RESULTS Correlations between the pedometer and the criterion method were high for SC during slow and fast walking (r=.79 and r=.95) and for EE during fast walking (r=.83). Correlation was more modest for EE during slow walking (r=.65) and for WD and WI during both speeds (.47<r<.68). The agreement between methods was also good, according to Bland-Altman plots. The device was reproducible for registering SC, WD, and EE during slow walking and for all variables during fast walking (intraclass correlation coefficient >.79 for all). During the ADLs circuit, the pedometer underestimated AT by an average of 55% but provided an acceptable EE estimation in a group basis (average difference of 6% with the multisensor). CONCLUSIONS In patients with COPD, the new pedometer analyzed in the present study is reproducible for most outcomes and highly valid for SC during slow and fast walking and EE during fast walking. The devices validity is more limited for EE during slow walking, and WD and WI at both speeds. Furthermore, during the performance of ADLs, it significantly underestimates activity time but provides an acceptable estimation of EE in a group basis.

Minimal detectable change of the London chest activity of daily living scale in patients with COPD.

BACKGROUND: Dyspnea and fatigue frequently impair the ability to perform activities of daily living (ADL) in patients with chronic obstructive pulmonary disease. Questionnaires and scales have been used to assess limitations in ADL. The London Chest Activity of Daily Living (LCADL) scale is responsive to intervention to a higher extent when compared with other tools. However, the minimal detectable change (MDC) for this scale remains unknown. The aim of this study was to determine the MDC for functional status improvement measured by the LCADL scale in patients with chronic obstructive pulmonary disease. METHODS: Forty patients (20 men, 66 ± 7 years, forced expired volume in 1 second 44 ± 16% predicted) participated in a 3-month high-intensity exercise training program. Before and after the protocol, participants complete the LCADL scale and the Saint George Respiratory Questionnaire. To calculate the MDC, we used the standard error of measurement and the effect size (distribution-based estimates). RESULTS: There was improvement in the LCADL self-care, domestic and leisure domains, and total score after the training program, with a strong trend for improvement in the physical activity domain. The MDC estimated for the LCADL were 0.89, 2.60, 0.44, 0.58, and 3.88 points for self-care, domestic, physical, and leisure domains, and total score, respectively. Correlations between changes in LCADL and in the Saint George Respiratory Questionnaire were weak (r < 0.4 for all). CONCLUSION: This study provided the MDC for the domains and total score of the LCADL. A change of 4 points in the total score of the LCADL can be interpreted as a meaningful change.