***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 Obstructive airways disease in older patients is reported to be not only common , but frequently overlooked and untreated by general practitioners . This study examines the value of screening elderly patients in a large semi-rural general practice for potentially treatable asthma and chronic obstructive pulmonary disease ( COPD ) . METHODS A r and om sample of 353 patients aged 60–75 years attended a nurse run screening clinic for pulmonary function testing , serial peak flow recording , and completion of a symptom question naire .  Patients with a low forced expiratory volume in one second ( below the fifth centile of their predicted value ) or > 15 % mean diurnal variation in peak flow were referred to a doctor ’s clinic for further diagnostic assessment and /or to discuss possible treatment where appropriate . RESULTS Fifty eight patients ( 16.4 % ) had obstructive airways disease , the prevalence of asthma being 6.5 % and that of COPD 9.9 % . Of these , 30 had no previous diagnosis of airways disease and were not on treatment ; eight of them had significant airways reversibility and 10 were current smokers . No newly diagnosed patients had severe disease as measured by pulmonary function or quality of life assessment , and six patients accepted treatment . CONCLUSION Few older patients benefited from a screening programme for obstructive airways disease in a semi-rural general practice OBJECTIVES The prevalence of COPD in Greece is unknown . The aim of this study was to determine the prevalence and trends of COPD among adults in Greece . METHODS This study involved 888 r and omly identified adults ( 475 men and 413 women ) aged > 35 years , and smokers of at least 100 cigarettes , in a population -based , multiregional , cross-sectional descriptive design . The selected individuals reflected the urban/rural population distribution in Greece and , within each study region , the age group and gender of the community setting . The diagnosis of COPD was based on clinical and spirometric data including reversibility test ( DeltaFEV(1 ) < 15 % ) . RESULTS The overall prevalence of COPD in the population aged > 35 years with a smoking history of > 100 cigarettes per lifetime was 8.4 % . The gender-st and ardized COPD prevalence was 11.6 % for men and 4.8 % for women . The COPD prevalence by community setting was as follows : Athens , 6 % ; other urban areas , 10.1 % ; semiurban areas , 8.5 % ; and rural areas , 9.1 % . Smoking intensity and age were significantly associated with higher COPD prevalence in both men and women . CONCLUSIONS COPD is a substantial health problem in Greece , although prevalence rates are lower than expected when the high smoking rates are taken into account . The high proportion of the patients with mild COPD who were unaware of their illness highlights the need to increase public awareness of COPD BACKGROUND Previous studies showing that tiotropium improves multiple end points in patients with chronic obstructive pulmonary disease ( COPD ) led us to examine the long-term effects of tiotropium therapy . METHODS In this r and omized , double-blind trial , we compared 4 years of therapy with either tiotropium or placebo in patients with COPD who were permitted to use all respiratory medications except inhaled anticholinergic drugs . The patients were at least 40 years of age , with a forced expiratory volume in 1 second ( FEV(1 ) ) of 70 % or less after bronchodilation and a ratio of FEV(1 ) to forced vital capacity ( FVC ) of 70 % or less . Co primary end points were the rate of decline in the mean FEV(1 ) before and after bronchodilation beginning on day 30 . Secondary end points included measures of FVC , changes in response on St. George 's Respiratory Question naire ( SGRQ ) , exacerbations of COPD , and mortality . RESULTS Of a total of 5993 patients ( mean age , 65+/-8 years ) with a mean FEV(1 ) of 1.32+/-0.44 liters after bronchodilation ( 48 % of predicted value ) , we r and omly assigned 2987 to the tiotropium group and 3006 to the placebo group . Mean absolute improvements in FEV(1 ) in the tiotropium group were maintained throughout the trial ( ranging from 87 to 103 ml before bronchodilation and from 47 to 65 ml after bronchodilation ) , as compared with the placebo group ( P<0.001 ) . After day 30 , the differences between the two groups in the rate of decline in the mean FEV(1 ) before and after bronchodilation were not significant . The mean absolute total score on the SGRQ was improved ( lower ) in the tiotropium group , as compared with the placebo group , at each time point throughout the 4-year period ( ranging from 2.3 to 3.3 units , P<0.001 ) . At 4 years and 30 days , tiotropium was associated with a reduction in the risks of exacerbations , related hospitalizations , and respiratory failure . CONCLUSIONS In patients with COPD , therapy with tiotropium was associated with improvements in lung function , quality of life , and exacerbations during a 4-year period but did not significantly reduce the rate of decline in FEV(1 ) . ( Clinical Trials.gov number , NCT00144339 . Background The clinical effects of mucolytics in patients with chronic obstructive pulmonary disease ( COPD ) are discussed controversially . Cineole is the main constituent of eucalyptus oil and mainly used in inflammatory airway diseases as a mucolytic agent . We hypothesised that its known mucolytic , bronchodilating and anti-inflammatory effects as concomitant therapy would reduce the exacerbation rate and show benefits on pulmonary function tests as well as quality of life in patients with COPD . Methods In this double-blind , placebo-controlled multi-center- study we r and omly assigned 242 patients with stable COPD to receive 200 mg of cineole or placebo 3 times daily as concomitant therapy for 6 months during winter-time . The frequency , duration and severity of exacerbations were combined as primary outcome measures for testing as multiple criteria . Secondary outcome measures included changes of lung function , respiratory symptoms and quality of life as well as the single parameters of the exacerbations . Results Baseline demographics , lung function and st and ard medication of both groups were comparable . During the treatment period of 6 months the multiple criteria frequency , severity and duration of exacerbations were significantly lower in the group treated with cineole in comparison to placebo . Secondary outcome measures vali date d these findings . Improvement of lung function , dyspnea and quality of life as multiple criteria were statistically significant relative to placebo . Adverse events were comparable in both groups . Conclusion Concomitant therapy with cineole reduces exacerbations as well as dyspnea and improves lung function and health status . This study further suggests cineole as an active controller of airway inflammation in COPD by intervening in the pathophysiology of airway inflammation of the mucus membrane . Trial registration IS RCT The present work aims to assess the international variation in the prevalence of chronic bronchitis and its main risk factor , smoking habits , in young adults of 35 centres from 16 countries .  Respiratory symptoms and pulmonary function were assessed in 17,966 subjects ( 20 - 44 yrs ) , r and omly selected from the general population , in the frame of the European Community Respiratory Health Survey . The median prevalence of chronic bronchitis was 2.6 % , with wide variations across countries ( p<0.001 ; 0.7 - 9.7 % ) . The prevalence of current smokers ranged 20.1 - 56.9 % , ( p<0.001 ) with a median value of 40 % . Current smoking was the major risk factor for chronic bronchitis , especially in males . Its effect increased according to number of pack-yrs : in males , the odds ratio of chronic bronchitis was 3.51 ( 95 % confidence interval ( CI ) 2.31 - 5.32 ) in 1 - 14 pack-yrs smokers and increased to 17.32 ( 9.97 - 30.11 ) in > or = 45 pack-yrs smokers with respect to nonsmokers . Only 30 % of the geographical variability in prevalence could be explained by differences in smoking habits , suggesting that other environmental and /or genetic factors may play an important role . In conclusion , chronic bronchitis is a substantial health problem even in young adults . The impressive prevalence in current smokers in most countries highlights the need to improve the quality of prevention RATIONALE Exacerbations are key drivers of morbidity and mortality in chronic obstructive pulmonary disease ( COPD ) . OBJECTIVES We compared the relative efficacy of the long-acting inhaled bronchodilator/antiinflammatory combination ( salmeterol/fluticasone propionate ) 50/500 microg twice daily and the long-acting bronchodilator ( tiotropium ) 18 microg once daily in preventing exacerbations and related outcomes in severe and very severe COPD . METHODS A total of 1,323 patients ( mean age , 64 yr , post-bronchodilator FEV1 , 39 % predicted ) were r and omized in this 2-year , double-blind , double-dummy parallel study . MEASUREMENTS AND MAIN RESULTS Primary endpoint was health care utilization exacerbation rate . Other endpoints included health status measured by St. George 's Respiratory Question naire ( SGRQ ) , mortality , adverse events , and study withdrawal . Probability of withdrawing from the study was 29 % greater with tiotropium than salmeterol/fluticasone propionate ( P = 0.005 ) . The modeled annual exacerbation rate was 1.28 in the salmeterol/fluticasone propionate group and 1.32 in the tiotropium group ( rate ratio , 0.967 ; 95 % confidence interval [ CI ] , 0.836 - 1.119 ] ; P = 0.656 ) . The SGRQ total score was statistically significantly lower at 2 years on salmeterol/fluticasone propionate versus tiotropium ( difference 2.1 units ; 95 % CI , 0.1 - 4.0 ; P = 0.038 ) . Mortality was significantly lower in the salmeterol/fluticasone propionate group ; 21 ( 3 % ) of patients in this group died compared with 38 ( 6 % ) in the tiotropium group ( P = 0.032 ) . More pneumonias were reported in the salmeterol/fluticasone propionate group relative to tiotropium ( P = 0.008 ) . CONCLUSIONS We found no difference in exacerbation rate between salmeterol/fluticasone propionate and tiotropium . More patients failed to complete the study while receiving tiotropium . A small statistically significant beneficial effect was found on health status , with an unexpected finding of lower deaths in salmeterol/fluticasone propionate-treated patients . Clinical trial registered with www . clinical trials.gov ( NCT 00361959 ) BACKGROUND Patients with chronic obstructive pulmonary disease ( COPD ) often present with severe acute exacerbations requiring hospital treatment . However , little is known about the prognostic consequences of these exacerbations . A study was undertaken to investigate whether severe acute exacerbations of COPD exert a direct effect on mortality . METHODS Multivariate techniques were used to analyse the prognostic influence of acute exacerbations of COPD treated in hospital ( visits to the emergency service and admissions ) , patient age , smoking , body mass index , co-morbidity , long term oxygen therapy , forced spirometric parameters , and arterial blood gas tensions in a prospect i ve cohort of 304 men with COPD followed up for 5 years . The mean ( SD ) age of the patients was 71 ( 9 ) years and forced expiratory volume in 1 second was 46 (17)% . RESULTS Only older age ( hazard ratio ( HR ) 5.28 , 95 % CI 1.75 to 15.93 ) , arterial carbon dioxide tension ( HR 1.07 , 95 % CI 1.02 to 1.12 ) , and acute exacerbations of COPD were found to be independent indicators of a poor prognosis . The patients with the greatest mortality risk were those with three or more acute COPD exacerbations ( HR 4.13 , 95 % CI 1.80 to 9.41 ) . CONCLUSIONS This study shows for the first time that severe acute exacerbations of COPD have an independent negative impact on patient prognosis . Mortality increases with the frequency of severe exacerbations , particularly if these require admission to hospital This r and omised , double-blind , parallel-group , 1-yr study compared the effect of tiotropium 18 microg once daily ( n=500 ) and placebo  ( n=510 ) on exacerbations , associated health re source use ( HRU ) and  airflow limitation in chronic obstructive pulmonary disease ( COPD ) patients . The mean+/-sd number of exacerbations during the past year was 2.14+/-1.40 , the mean weekly morning peak expiratory flow ( PEF ) was 259.6+/-96.1 L.min-1 and the mean forced expir 
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The methods used to estimate these epidemiological parameters were highly variable in terms of the definition of COPD , severity scales , methods of investigation and target population s. Nevertheless , to a large extent , several recent international guidelines or research initiatives , such as GOLD , BOLD or PLATINO , have boosted a substantial st and ardization of methodology in data collection and have result ed in the availability of more comparable epidemiological estimates across countries .
On the basis of such st and ardization , severity estimates as well as prevalence estimates present much less variation across countries .
Conclusions The accuracy of COPD epidemiological parameters is important for guiding decision making with regard to preventive measures , interventions and patient management in various health care systems .