human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND AND OBJECTIVE Cycle ergometer training is an important component of pulmonary rehabilitation for patients with COPD . However , incremental cycle tests from which individualized cycle training intensity can be prescribed may not be readily available to clinicians . The aims of the study were to ( i ) investigate the physiological and psychophysical responses to the 6-min walk test ( 6MWT ) , incremental shuttle walk test ( ISWT ) and cycle ergometer test ( CET ) ; and ( ii ) determine whether the distance walked in either the 6MWT or the ISWT could be used to estimate peak work rate on a cycle ergometer . METHODS A repeated measures study was undertaken in COPD patients in a stable condition . The 6MWT , ISWT and CET were performed in r and om order , and physiological responses , rate of perceived exertion and dyspnoea were measured . RESULTS Twenty-two patients with COPD completed the study . There was no significant difference in peak oxygen uptake between the 6MWT , ISWT and CET . The significant correlation between the 6MWD and incremental shuttle walk distance with peak watts on the CET ( r = 0.63 , P = 0.002 and r = 0.75 , P < 0.001 , respectively ) was strengthened by the inclusion of weight , age and gender ( r = 0.89 P = 0.001 and r = 0.91 , P < 0.001 ) . Bl and -Altman analysis demonstrated a strong agreement between peak work rate measured on the CET and that estimated from either the 6MWT or the ISWT . CONCLUSIONS The significant relationships found between the three exercise tests , and the regression equations predicting peak work rate on the CET from the 6MWT or the ISWT , may allow for the estimation of intensity of cycle exercise training from walk tests in COPD patients Background In patients with COPD , both laboratory exercise tests and field walking tests are used to assess physical performance . In laboratory tests , peak exercise capacity in watts ( W peak ) and /or peak oxygen uptake ( VO2 peak ) are assessed , whereas the performance on walking tests usually is expressed as distance walked . The aim of the study was to investigate the relationship between an incremental shuttle walking test ( ISWT ) and two laboratory cycle tests in order to assess whether W peak could be estimated from an ISWT . Methods Ninety-three patients with moderate or severe COPD performed an ISWT , an incremental cycle test ( ICT ) to measure W peak and a semi-steady-state cycle test with breath-by-breath gas exchange analysis ( CPET ) to measure VO2 peak . Routine equations for conversion between cycle tests were used to estimate W peak from measured VO2 peak ( CPET ) . Conversion equation for estimation of W peak from ISWT was found by univariate regression . Results There was a significant correlation between W peak and distance walked on ISWT × body weight ( r = 0.88 , p < 0.0001 ) . The agreement between W peak measured by ICT and estimated from ISWT was similar to the agreement between measured W peak ( ICT ) and W peak estimated from measured VO2 peak by CPET . Conclusion Peak exercise capacity measured by an incremental cycle test could be estimated from an ISWT with similar accuracy as when estimated from peak oxygen uptake in patients with COPD Background : Ambulatory oxygen is frequently prescribed for patients with chronic obstructive pulmonary disease ( COPD ) who have oxygen desaturation ≤88 % during exercise . The 6-min walk test ( 6MWT ) with continuous pulse oximetry monitoring is a common method to document this oxygen desaturation , but the reproducibility of this test in determining the need for ambulatory oxygen in patients with COPD is not well documented . Objective : The aim of this study was to establish the reproducibility of the 6MWT in determining the need for ambulatory oxygen prescription in stable COPD patients using the Centers for Medicare and Medicaid ( CMS ) criteria for ambulatory oxygen prescription . Methods : The study was design ed as a prospect i ve observational study in an academic health center and associated pulmonary rehabilitation program . Eighty-eight COPD patients referred to pulmonary rehabilitation underwent continuous pulse oximetry while performing st and ard 6MWT on 3 separate days . Results : Fifty-one ( 58 % ) of these patients desaturated by continuous pulse oximetry to an SpO2 ≤88 % on a least one of the 6MWTs . Only 26 patients ( 30 % ) demonstrated consistency in meeting the criteria for ambulatory oxygen set forth by the CMS on all three 6MWT with a κ statistic of 0.62 . The percent agreement between 6MWTs for ambulatory oxygen prescription was 72 % and the paired observation was 51 % . Conclusions : The 6MWT distance is simple and widely used as a consistent measure of functional capacity in patients with COPD ; however , the 6MWT oxygen saturation has only modest reproducibility in determining the need for ambulatory oxygen in stable COPD patients undergoing pulmonary rehabilitation Respiratory rehabilitation improves exercise capacity and quality of life in younger patients but is untried in the aged . We aim ed to : ( a ) assess repeatability of the 6-minute walk test , factors affecting it and its relation to quality of life in elderly patients with chronic obstructive airways disease ( COAD ) ; ( b ) assess compliance of such patients with an intensive respiratory rehabilitation protocol ; ( c ) pilot the assessment of the effect of respiratory rehabilitation on the 6-minute walk test in these patients . Seventeen subjects with stable , symptomatic COAD were recruited , 15 ( six men ) , 70 - 89 ( mean 76 ) years , completed the study . Mean ( st and ard deviation ) 1-second forced expiratory volume ( FEV1 ) = 49 (5)% predicted . Six-minute walk tests were repeated single-blind , 2 - 10 days apart . Quality of life was measured using Guyatt respiratory question naire . Patients underwent 12 weeks incremental respiratory rehabilitation ( x4/day step-ups , unweighed arm raises , inflating balloons ) . Baseline 6-minute walk was repeatable and was correlated with the log Guyatt dyspnoea score ( r = 0.65 , p = 0.006 ) . In multiple regression neither age nor FEV1 predicted walk distance : body mass index , maximal expiratory mouth pressure ; calorie intake . Mean ( SEM ) 6-minute walk distance after-rehabilitation was greater than baseline ( p = 0.003 ) . Elderly patients with COAD tolerate intensive respiratory rehabilitation and a controlled , blinded study is needed BACKGROUND The protocol used for the 6-min walk test ( 6MWT ) influences its results . The only study to examine the effect of modifying track layout performed a retrospective analysis and concluded that institutions using continuous tracks yield greater distances than those using straight tracks . Agreement between the distances measured on different tracks could not be examined . We evaluated the effect of modifying track layout on walk distance and examined the agreement and repeatability of distances measured on different tracks . METHODS In a prospect i ve , r and omized , cross-over study , 27 COPD subjects ( FEV(1 ) , 38 + /- 14 % [ mean + /- SD ] ; 15 men ) attended three separate test sessions , completing six 6MWTs . To familiarize all subjects with both tracks , the first two sessions comprised two 6MWTs on either a circular or straight track . During the final session , each subject was tested once on the straight and once on the circular track . RESULTS The distance walked on the circular track exceeded the straight track by 13 + /- 17 m ( p < 0.001 ) . The limit of agreement between tracks was 33 m. Coefficient of repeatability values when the test was completed on different days for the straight and circular tracks were 51 m and 65 m , respectively . CONCLUSIONS When evaluating changes in 6-min walk distance in groups of patients , track layout should be st and ardized . However , the effect of modifying track layout on an individual 's walking distance is small compared to their daily variability in walk distance . Therefore , st and ardizing track layout for any given individual may be inconsequential when evaluating the change in distances from tests performed on different days Background : The responsiveness of the endurance shuttle walk to functional changes following bronchodilation has recently been reported . The current literature suggests that the 6 min walking test ( 6MWT ) is less responsive to bronchodilation than the endurance shuttle walk . Aim : To compare bronchodilator-induced changes in exercise performance with the 6MWT and the endurance shuttle walk . Methods : In a r and omised , double-blind , placebo-controlled , crossover trial , 14 patients with chronic obstructive pulmonary disease ( forced expiratory volume in 1 s ( FEV1 ) 50 (8)% predicted ) completed two 6MWTs and two endurance shuttle walks , each preceded by nebulised placebo or 500 μg ipratropium bromide .  Cardiorespiratory parameters were monitored during each walking test with a portable telemetric gas analyser . Quadriceps twitch force was measured by magnetic stimulation of the femoral nerve before and after each walking test . Results : The 6 min walking distance did not change significantly after bronchodilation despite a significant increase in FEV1 of 0.18 ( 0.09 ) litres ( p<0.001 ) . A similar change in FEV1 ( 0.18 ( 0.12 ) litres , p<0.001 ) was associated with a significant improvement in the distance walked on the endurance shuttle walk ( Δdistance ipratropium bromide – placebo = 144 ( 219 ) m , p = 0.03 ) . Quadriceps muscle fatigue was infrequent ( < 15 % of patients ) after both walking tests . Conclusion : The endurance shuttle walk is more responsive than the 6MWT for detecting changes in exercise performance following bronchodilation We assessed the  6-min walk distance ( 6MWD ) and  body weight x distance product ( 6MWw ) in healthy Brazilian subjects and compared measured 6MWD with values predicted in five reference equations developed for other population s. Anthropometry , spirometry , reported physical activity , and two walk tests in a 30-m corridor were evaluated in 134 subjects ( 73 females , 13 - 84 years ) .  Mean 6MWD and 6MWw were significantly greater in males than in females ( 622 + /- 80 m , 46,322 + /- 10,539 kg.m vs 551 + /- 71 m , 36,356 + /- 8,289 kg.m , P < 0.05 ) . Four equations significantly overestimated measured 6MWD ( range , 32 + /- 71 to 137 + /- 74 m ; P < 0.001 ) , and one significantly underestimated it ( -36 + /- 86 m ; P < 0.001 ) . 6MWD significantly correlated with age ( r = -0.39 ) , height ( r = 0.44 ) , body mass index ( r = -0.24 ) , and reported physical activity ( r = 0.25 ) . 6MWw significantly correlated with age ( r = -0.21 ) , height ( r = 0.66 ) and reported physical activity ( r = 0.25 ) . The reference equation devised for walk distance was 6MWDm = 622.461 - ( 1.846 x Ageyears ) + ( 61.503 x Gendermales = 1 ; females = 0 ) ; r2 = 0.300 . In an additional group of 85 subjects prospect ively studied , the difference between measured and the 6MWD predicted with the equation proposed here was not significant ( -3 + /- 68 m ; P = 0.938 ) . The measured 6MWD represented 99.6 + /- 11.9 % of the predicted value . We conclude that 6MWD and 6MWw variances were adequately explained by demographic and anthropometric attributes . This reference equation is probably most appropriate for evaluating the exercise capacity of Brazilian patients with chronic diseases Background The COPD ( chronic obstructive pulmonary disease ) assessment test ( CAT ) is a recently introduced , simple to use patient-completed quality of life instrument that contains eight questions covering the impact of symptoms in COPD . It is not known how the CAT score performs in the context of clinical pulmonary rehabilitation ( PR ) programmes or what the minimum clinical ly important difference is . Methods The introduction of the  CAT score as an outcome measure was prospect ively studied by PR programmes across London . It was used alongside other measures including the St George 's Respiratory Question naire , the Chronic Respiratory Disease Question naire , the Clinical COPD Question naire , the Hospital Anxiety and Depression score , the Medical Research Council ( MRC ) dyspnoea score and a range of different walking tests . Patients completed a 5-point anchor question used to assess overall response to PR from ‘ I feel much better ’ to ‘ I feel much worse ’ . Results Data were available for 261 patients with COPD participating in seven programmes : mean ( SD ) age 69.0 ( 9.0 ) years , forced expiratory volume in 1 s ( FEV1 ) 51.1 ( 18.7 ) % predicted , MRC score 3.2 ( 1.0 ) . Mean change in CAT score after PR was 2.9 ( 5.6 ) points , improving by 3.8 ( 6.1 ) points in those scoring ‘ much better ’ ( n=162 ) , and by 1.3(4.5 ) in those who felt ‘ a little better ’ ( n=88 ) ( p=0.002 ) . Only eight individuals reported no difference after PR and three reported feeling ‘ a little worse 
    Output:
    
agent
Method ological 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
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND AND OBJECTIVE Cycle ergometer training is an important component of pulmonary rehabilitation for patients with COPD . However , incremental cycle tests from which individualized cycle training intensity can be prescribed may not be readily available to clinicians . The aims of the study were to ( i ) investigate the physiological and psychophysical responses to the 6-min walk test ( 6MWT ) , incremental shuttle walk test ( ISWT ) and cycle ergometer test ( CET ) ; and ( ii ) determine whether the distance walked in either the 6MWT or the ISWT could be used to estimate peak work rate on a cycle ergometer . METHODS A repeated measures study was undertaken in COPD patients in a stable condition . The 6MWT , ISWT and CET were performed in r and om order , and physiological responses , rate of perceived exertion and dyspnoea were measured . RESULTS Twenty-two patients with COPD completed the study . There was no significant difference in peak oxygen uptake between the 6MWT , ISWT and CET . The significant correlation between the 6MWD and incremental shuttle walk distance with peak watts on the CET ( r = 0.63 , P = 0.002 and r = 0.75 , P < 0.001 , respectively ) was strengthened by the inclusion of weight , age and gender ( r = 0.89 P = 0.001 and r = 0.91 , P < 0.001 ) . Bl and -Altman analysis demonstrated a strong agreement between peak work rate measured on the CET and that estimated from either the 6MWT or the ISWT . CONCLUSIONS The significant relationships found between the three exercise tests , and the regression equations predicting peak work rate on the CET from the 6MWT or the ISWT , may allow for the estimation of intensity of cycle exercise training from walk tests in COPD patients Background In patients with COPD , both laboratory exercise tests and field walking tests are used to assess physical performance . In laboratory tests , peak exercise capacity in watts ( W peak ) and /or peak oxygen uptake ( VO2 peak ) are assessed , whereas the performance on walking tests usually is expressed as distance walked . The aim of the study was to investigate the relationship between an incremental shuttle walking test ( ISWT ) and two laboratory cycle tests in order to assess whether W peak could be estimated from an ISWT . Methods Ninety-three patients with moderate or severe COPD performed an ISWT , an incremental cycle test ( ICT ) to measure W peak and a semi-steady-state cycle test with breath-by-breath gas exchange analysis ( CPET ) to measure VO2 peak . Routine equations for conversion between cycle tests were used to estimate W peak from measured VO2 peak ( CPET ) . Conversion equation for estimation of W peak from ISWT was found by univariate regression . Results There was a significant correlation between W peak and distance walked on ISWT × body weight ( r = 0.88 , p < 0.0001 ) . The agreement between W peak measured by ICT and estimated from ISWT was similar to the agreement between measured W peak ( ICT ) and W peak estimated from measured VO2 peak by CPET . Conclusion Peak exercise capacity measured by an incremental cycle test could be estimated from an ISWT with similar accuracy as when estimated from peak oxygen uptake in patients with COPD Background : Ambulatory oxygen is frequently prescribed for patients with chronic obstructive pulmonary disease ( COPD ) who have oxygen desaturation ≤88 % during exercise . The 6-min walk test ( 6MWT ) with continuous pulse oximetry monitoring is a common method to document this oxygen desaturation , but the reproducibility of this test in determining the need for ambulatory oxygen in patients with COPD is not well documented . Objective : The aim of this study was to establish the reproducibility of the 6MWT in determining the need for ambulatory oxygen prescription in stable COPD patients using the Centers for Medicare and Medicaid ( CMS ) criteria for ambulatory oxygen prescription . Methods : The study was design ed as a prospect i ve observational study in an academic health center and associated pulmonary rehabilitation program . Eighty-eight COPD patients referred to pulmonary rehabilitation underwent continuous pulse oximetry while performing st and ard 6MWT on 3 separate days . Results : Fifty-one ( 58 % ) of these patients desaturated by continuous pulse oximetry to an SpO2 ≤88 % on a least one of the 6MWTs . Only 26 patients ( 30 % ) demonstrated consistency in meeting the criteria for ambulatory oxygen set forth by the CMS on all three 6MWT with a κ statistic of 0.62 . The percent agreement between 6MWTs for ambulatory oxygen prescription was 72 % and the paired observation was 51 % . Conclusions : The 6MWT distance is simple and widely used as a consistent measure of functional capacity in patients with COPD ; however , the 6MWT oxygen saturation has only modest reproducibility in determining the need for ambulatory oxygen in stable COPD patients undergoing pulmonary rehabilitation Respiratory rehabilitation improves exercise capacity and quality of life in younger patients but is untried in the aged . We aim ed to : ( a ) assess repeatability of the 6-minute walk test , factors affecting it and its relation to quality of life in elderly patients with chronic obstructive airways disease ( COAD ) ; ( b ) assess compliance of such patients with an intensive respiratory rehabilitation protocol ; ( c ) pilot the assessment of the effect of respiratory rehabilitation on the 6-minute walk test in these patients . Seventeen subjects with stable , symptomatic COAD were recruited , 15 ( six men ) , 70 - 89 ( mean 76 ) years , completed the study . Mean ( st and ard deviation ) 1-second forced expiratory volume ( FEV1 ) = 49 (5)% predicted . Six-minute walk tests were repeated single-blind , 2 - 10 days apart . Quality of life was measured using Guyatt respiratory question naire . Patients underwent 12 weeks incremental respiratory rehabilitation ( x4/day step-ups , unweighed arm raises , inflating balloons ) . Baseline 6-minute walk was repeatable and was correlated with the log Guyatt dyspnoea score ( r = 0.65 , p = 0.006 ) . In multiple regression neither age nor FEV1 predicted walk distance : body mass index , maximal expiratory mouth pressure ; calorie intake . Mean ( SEM ) 6-minute walk distance after-rehabilitation was greater than baseline ( p = 0.003 ) . Elderly patients with COAD tolerate intensive respiratory rehabilitation and a controlled , blinded study is needed BACKGROUND The protocol used for the 6-min walk test ( 6MWT ) influences its results . The only study to examine the effect of modifying track layout performed a retrospective analysis and concluded that institutions using continuous tracks yield greater distances than those using straight tracks . Agreement between the distances measured on different tracks could not be examined . We evaluated the effect of modifying track layout on walk distance and examined the agreement and repeatability of distances measured on different tracks . METHODS In a prospect i ve , r and omized , cross-over study , 27 COPD subjects ( FEV(1 ) , 38 + /- 14 % [ mean + /- SD ] ; 15 men ) attended three separate test sessions , completing six 6MWTs . To familiarize all subjects with both tracks , the first two sessions comprised two 6MWTs on either a circular or straight track . During the final session , each subject was tested once on the straight and once on the circular track . RESULTS The distance walked on the circular track exceeded the straight track by 13 + /- 17 m ( p < 0.001 ) . The limit of agreement between tracks was 33 m. Coefficient of repeatability values when the test was completed on different days for the straight and circular tracks were 51 m and 65 m , respectively . CONCLUSIONS When evaluating changes in 6-min walk distance in groups of patients , track layout should be st and ardized . However , the effect of modifying track layout on an individual 's walking distance is small compared to their daily variability in walk distance . Therefore , st and ardizing track layout for any given individual may be inconsequential when evaluating the change in distances from tests performed on different days Background : The responsiveness of the endurance shuttle walk to functional changes following bronchodilation has recently been reported . The current literature suggests that the 6 min walking test ( 6MWT ) is less responsive to bronchodilation than the endurance shuttle walk . Aim : To compare bronchodilator-induced changes in exercise performance with the 6MWT and the endurance shuttle walk . Methods : In a r and omised , double-blind , placebo-controlled , crossover trial , 14 patients with chronic obstructive pulmonary disease ( forced expiratory volume in 1 s ( FEV1 ) 50 (8)% predicted ) completed two 6MWTs and two endurance shuttle walks , each preceded by nebulised placebo or 500 μg ipratropium bromide .  Cardiorespiratory parameters were monitored during each walking test with a portable telemetric gas analyser . Quadriceps twitch force was measured by magnetic stimulation of the femoral nerve before and after each walking test . Results : The 6 min walking distance did not change significantly after bronchodilation despite a significant increase in FEV1 of 0.18 ( 0.09 ) litres ( p<0.001 ) . A similar change in FEV1 ( 0.18 ( 0.12 ) litres , p<0.001 ) was associated with a significant improvement in the distance walked on the endurance shuttle walk ( Δdistance ipratropium bromide – placebo = 144 ( 219 ) m , p = 0.03 ) . Quadriceps muscle fatigue was infrequent ( < 15 % of patients ) after both walking tests . Conclusion : The endurance shuttle walk is more responsive than the 6MWT for detecting changes in exercise performance following bronchodilation We assessed the  6-min walk distance ( 6MWD ) and  body weight x distance product ( 6MWw ) in healthy Brazilian subjects and compared measured 6MWD with values predicted in five reference equations developed for other population s. Anthropometry , spirometry , reported physical activity , and two walk tests in a 30-m corridor were evaluated in 134 subjects ( 73 females , 13 - 84 years ) .  Mean 6MWD and 6MWw were significantly greater in males than in females ( 622 + /- 80 m , 46,322 + /- 10,539 kg.m vs 551 + /- 71 m , 36,356 + /- 8,289 kg.m , P < 0.05 ) . Four equations significantly overestimated measured 6MWD ( range , 32 + /- 71 to 137 + /- 74 m ; P < 0.001 ) , and one significantly underestimated it ( -36 + /- 86 m ; P < 0.001 ) . 6MWD significantly correlated with age ( r = -0.39 ) , height ( r = 0.44 ) , body mass index ( r = -0.24 ) , and reported physical activity ( r = 0.25 ) . 6MWw significantly correlated with age ( r = -0.21 ) , height ( r = 0.66 ) and reported physical activity ( r = 0.25 ) . The reference equation devised for walk distance was 6MWDm = 622.461 - ( 1.846 x Ageyears ) + ( 61.503 x Gendermales = 1 ; females = 0 ) ; r2 = 0.300 . In an additional group of 85 subjects prospect ively studied , the difference between measured and the 6MWD predicted with the equation proposed here was not significant ( -3 + /- 68 m ; P = 0.938 ) . The measured 6MWD represented 99.6 + /- 11.9 % of the predicted value . We conclude that 6MWD and 6MWw variances were adequately explained by demographic and anthropometric attributes . This reference equation is probably most appropriate for evaluating the exercise capacity of Brazilian patients with chronic diseases Background The COPD ( chronic obstructive pulmonary disease ) assessment test ( CAT ) is a recently introduced , simple to use patient-completed quality of life instrument that contains eight questions covering the impact of symptoms in COPD . It is not known how the CAT score performs in the context of clinical pulmonary rehabilitation ( PR ) programmes or what the minimum clinical ly important difference is . Methods The introduction of the  CAT score as an outcome measure was prospect ively studied by PR programmes across London . It was used alongside other measures including the St George 's Respiratory Question naire , the Chronic Respiratory Disease Question naire , the Clinical COPD Question naire , the Hospital Anxiety and Depression score , the Medical Research Council ( MRC ) dyspnoea score and a range of different walking tests . Patients completed a 5-point anchor question used to assess overall response to PR from ‘ I feel much better ’ to ‘ I feel much worse ’ . Results Data were available for 261 patients with COPD participating in seven programmes : mean ( SD ) age 69.0 ( 9.0 ) years , forced expiratory volume in 1 s ( FEV1 ) 51.1 ( 18.7 ) % predicted , MRC score 3.2 ( 1.0 ) . Mean change in CAT score after PR was 2.9 ( 5.6 ) points , improving by 3.8 ( 6.1 ) points in those scoring ‘ much better ’ ( n=162 ) , and by 1.3(4.5 ) in those who felt ‘ a little better ’ ( n=88 ) ( p=0.002 ) . Only eight individuals reported no difference after PR and three reported feeling ‘ a little worse 
    Output:
    