***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: OBJECTIVE This study attempted to determine the total direct costs derived from the management of chronic bronchitis and COPD in an ambulatory setting through a prospect i ve , 1-year , follow-up study . METHOD A total of 1,510 patients with chronic bronchitis and COPD were recruited from 268 general practice s located throughout Spain . Patients were followed up for 1 year . All direct medical costs incurred by the cohort and related to their respiratory disease were quantified . Costs were calculated for patients with confirmed COPD according to the degree of severity of airflow obstruction . RESULTS The global mean direct yearly cost of chronic bronchitis and COPD was $ 1,876 . The cost generated by patients with COPD was $ 1,760 , but the cost of severe COPD ( $ 2,911 ) was almost double that of mild COPD ( $ 1,484 ) . Hospitalization costs represented 43.8 % of costs , drug acquisition costs were 40.8 % , and clinic visits and diagnostic tests represented only 15.4 % of costs . CONCLUSION This is the first prospect i ve follow-up study on a large cohort of patients with chronic bronchitis and COPD aim ed at quantifying direct medical costs under usual clinical practice in the community . Costs of chronic bronchitis and COPD were almost twofold those reported for asthma . Patterns of COPD management in the community differ from those recommended in guidelines . COPD represents a great health-care burden in developed countries , and aging of the population and continuing smoking habits predict that it will continue to do so in the future Background Supporting 21st century health care and the practice of evidence -based medicine ( EBM ) requires ubiquitous access to clinical information and to knowledge-based re sources to answer clinical questions . Many questions go unanswered , however , due to lack of skills in formulating questions , crafting effective search strategies , and accessing data bases to identify best levels of evidence . Methods This r and omized trial was design ed as a pilot study to measure the relevancy of search results using three different interfaces for the PubMed search system . Two of the search interfaces utilized a specific framework called PICO , which was design ed to focus clinical questions and to prompt for publication type or type of question asked . The third interface was the st and ard PubMed interface readily available on the Web . Study subjects were recruited from interns and residents on an inpatient general medicine rotation at an academic medical center in the US . Thirty-one subjects were r and omized to one of the three interfaces , given 3 clinical questions , and asked to search PubMed for a set of relevant articles that would provide an answer for each question . The success of the search results was determined by a precision score , which compared the number of relevant or gold st and ard articles retrieved in a result set to the total number of articles retrieved in that set . Results Participants using the PICO templates ( Protocol A or Protocol B ) had higher precision scores for each question than the participants who used Protocol C , the st and ard PubMed Web interface . ( Question 1 : A = 35 % , B = 28 % , C = 20 % ; Question 2 : A = 5 % , B = 6 % , C = 4 % ; Question 3 : A = 1 % , B = 0 % , C = 0 % ) 95 % confidence intervals were calculated for the precision for each question using a lower boundary of zero . However , the 95 % confidence limits were overlapping , suggesting no statistical difference between the groups . Conclusion Due to the small number of search es for each arm , this pilot study could not demonstrate a statistically significant difference between the search protocol s. However there was a trend towards higher precision that needs to be investigated in a larger study to determine if PICO can improve the relevancy of search results Background Pulmonary rehabilitation ( PR ) is recognized as an evidence -based treatment in improving dyspnea and quality of life in patients with COPD . We evaluated the number needed to treat ( NNT ) to achieve an increase in physical capacity , as defined by a significant improvement in the six-minute walk test ( 6MWT ) in patients with COPD undergoing PR . Methods The study enrolled 284 patients aged 41 to 86 years ( mean age 69.4 years ) divided into two groups : a  study group ( 222 patients ) undergoing a PR program  , and a control group ( 62 patients ) treated only with drugs .  The study group included patients with COPD divided in four subgroups according to GOLD stages . Results In the study group , 142 out of 222 patients ( 64 % ) had an increase of at least 54 m in the 6MWT following PR versus 8 out of 62 patients ( 13 % ) in the control group after the same time interval . The NNT in the overall study group was 2 ; the same NNT was obtained in GOLD stages 2 , 3 , and 4 , but was 8 in stage 1 . Conclusions PR is highly effective in improving the exercise capacity of patients with COPD , as demonstrated by a valuable NNT , with better results in patients with a more severe disease Background Pulmonary rehabilitation is known to be a beneficial treatment for COPD patients . To date , however , there is no agreement for how long a rehabilitation program should be implemented . In addition , current views are that pulmonary rehabilitation does not improve FEV1 or even slow its decline in COPD patients . The aim of the study was to examine the efficacy of a 3 year outpatient pulmonary rehabilitation ( PR ) program for COPD patients on pulmonary function , exercise capability , and body mass index ( BMI ) . Methods A matched controlled trial was performed with outcome assessment s evaluated at 6 , 12 , 18 , 24 , 30 , and 36 months . Eighty patients with moderate to severe COPD ( age 63 ± 7 years ; FEV1 48 % ± 14 ) were recruited . The control group received st and ard care only , while in addition , the case study group received PR for duration of three years . These groups were matched for age , sex , BMI , FEV1 % and number of pack-years smoked . Results The decline in FEV1 after the three years was significantly lower in the PR group compared to control , 74 ml versus 149 ml , respectively ( p < 0.001 ) . Maximal sustained work and endurance time improved after a short period of PR and was maintained throughout the study , in contrast to the control group ( p < 0.01 ) . A decreased BMI was noted in the control group after three years , while in the PR group a mild improvement was seen ( p < 0.05 ) . Conclusion Three years of outpatient pulmonary rehabilitation result ed in modifying the disease progression of COPD , as well as improving physical performance in these patients OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity OBJECTIVE To establish the minimal important difference ( MID ) for the six-minute walk distance ( 6MWD ) in persons with chronic obstructive pulmonary disease ( COPD ) . DESIGN Analysis of data from an observational study using distribution- and anchor-based methods to determine the MID in 6MWD . SETTING Outpatient pulmonary rehabilitation program at 2 teaching hospitals . PARTICIPANTS Seventy-five patients with COPD ( 44 men ) in a stable clinical state with mean age 70 years ( SD 9 y ) , forced expiratory volume in one second 52 % ( SD 21 % ) predicted and baseline walking distance 359 meters ( SD 104 m ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Participants completed the  six-minute walk test  before and after a 7-week pulmonary rehabilitation program . Participants and clinicians completed a global rating of change score while blinded to the change in 6MWD . RESULTS The mean change in 6MWD in participants who reported themselves to be unchanged was 17.7 meters , compared with 60.2 meters in those who reported small change and 78.4 meters in those who reported substantial change ( P=.004 ) . Anchor-based methods identified an MID of 25 meters ( 95 % confidence interval 20 - 61 m ) . There was excellent agreement with distribution-based methods ( 25.5 - 26.5 m , kappa=.95 ) . A change in 6MWD of 14 % compared with baseline also represented a clinical ly important effect ; this threshold was less sensitive than for absolute change ( sensitivity .70 vs .85 ) . CONCLUSIONS The MID for 6MWD in COPD is 25 meters . Absolute change in 6MWD is a more sensitive indicator than percentage change from baseline . These data support the use of 6MWD as a patient-important outcome in research and clinical practice BACKGROUND The aim of our study was to determine the effect of one year of pulmonary rehabilitation ( PR ) on functional parameters and exacerbation rates in patients with chronic obstructive pulmonary disease ( COPD ) . METHODS A total of 100 patients were enrolled in a multidisciplinary  PR program . PR included endurance , resistance and respiratory muscle training . We performed spiroergometry , a modified Bruce Test and measurements of upper and lower limb contractility as well as inspiratory muscle strength before , six and 12 months after beginning rehabilitation . Additionally , we assessed the quality of life and the number of exacerbations and exacerbation days one year before and after starting rehabilitation . RESULTS 100 patients ( 42 female/58 male ) with COPD ( COPD IV-N=36 , COPD III-N=42 , COPD II-N=22 ) , a mean age of 60.5+/-9.6 years , BMI 25.8+/-6.0 attended a rehabilitation training program over a time period of one year .  Spiroergometry  ( VO2max from 1.1 to 1.3 l/min , P<0.05 ) , modified Bruce Test ( from 13+/-7 Min to 18+/-9 Min ; P<0.001 ) , upper limb ( from 39.9+/-3 to 52.9+/-8 kg ; P<0.001 ) and lower limb strength increased significantly ( from 85.3+/-45 to 131.5+/-57 kg ; P<0.001 ) . The maximal inspiratory pressure rose from 81.1 mbar to 108.8 mbar ( p<0.001 ) . There was no improvement in FEV1 or FEV1/FVC but Saint Georges Respiratory Question naire ( total score ) improved from 37.2+/-3.6 to 26.5+/-2.8 ; P<0.001 . The same was true for exacerbation rates ( they dropped from 2.8 to 0.8 ; P=0.006 ) and the number of hospitalization days ( from 27.3 to 3.3 , P<0.001 ) . CONCLUSIONS One year of outpatient pulmonary rehabilitation is an effective intervention leading to a significant improvement in exercise tolerance and quality of life in patients with COPD also reducing COPD exacerbation rates and hospitalizations 
    Output:
    
: Most of the PR programs had significant positive effects on exercise capacity and HRQOL in patients with mild COPD ; however , their effects on health-care re source use and lung function were inconclusive .