***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 
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    Input: Objectives Case finding is proposed as an important component of the forthcoming English National Clinical Strategy for chronic obstructive pulmonary disease ( COPD ) because of accepted widespread underdiagnosis worldwide . However the best method of identification is not known . The extent of undiagnosed clinical ly significant COPD in Engl and is described and the effectiveness of an active compared with an opportunistic approach to case finding is evaluated . Methods A cross-sectional analysis was carried out using using Health Survey for Engl and ( HSE ) 1995–1996 data supplemented with published literature . A model comparing an active approach ( mailed question naires plus opportunistic identification ) with an opportunistic-only approach of case finding among ever smokers aged 40–79 years was evaluated . There were 20 496 participants aged ≥30 years with valid lung function measurements . The main outcome measure was undiagnosed clinical ly significant COPD ( any respiratory symptom with both forced expiratory volume in 1 s (FEV1)/forced vital capacity ( FVC ) < 0.7 and FEV1 < 80 % predicted ) . Results 971 ( 4.7 % ) had clinical ly significant COPD , of whom 840 ( 86.5 % ) did not report a previous diagnosis . Undiagnosed cases were more likely to be female , and smoked less . 25.3 % had severe disease ( FEV1 < 50 % predicted ) , 38.5 % Medical Research Council ( MRC ) grade 3 dyspnoea and 44.1 % were current smokers . The active case-finding strategy can potentially identify 70 % more new cases than opportunistic identification alone ( 3.8 vs 2.2 per 100 targeted ) . Treating these new cases could reduce hospitalisations by at least 3300 per year in Engl and and deaths by 2885 over 3 years . Conclusions There is important undiagnosed clinical ly significant COPD in the population , and the addition of a systematic case-finding approach may be more effective in identifying these cases . The cost-effectiveness of this approach needs to be tested empirically in a prospect i ve study BACKGROUND The incidence of chronic obstructive pulmonary disease ( COPD ) is increasing in developed countries , as is the mortality rate . The main cause of COPD is smoking , and COPD is usually diagnosed at a late stage . AIM To evaluate a method to detect COPD at an early stage in smokers in a young age group ( 40 - 55 years ) . DESIGN OF STUDY Prospect i ve descriptive study . SETTING The city of Motala ( 45,000 inhabitants ) and its surrounding rural areas ( 43,000 inhabitants ) in south-east Sweden . Nineteen thous and , seven hundred and fifty subjects were between 40 and 55 years of age . According to Swedish statistics , approximately 27 % of this population are smokers . METHOD Smokers aged between 40 and 55 years were invited to have free spirometry testing in primary healthcare centres . Placards were placed in pharmacies and health centres and advertising was carried out locally twice a year . RESULTS A total of 512 smokers responded . The prevalence of COPD was 27 % ( n = 141 ) . The COPD was classified as mild obstruction in 85 % ( n = 120 ) , moderate in 13 % ( n = 18 ) and severe in 2 % ( n = 3 ) according to the European Respiratory Society classification . Knowledge of the disease COPD was acknowledged by 39 % of the responders to the question naire . Logistic regression analysis showed that age , male sex , number of pack years , dyspnoea and symptoms of chronic bronchitis significantly increased the odds of having COPD . The adjusted odds ratio was significant for having > 30 pack years . CONCLUSIONS This method of inviting relatively young smokers selected a population of smokers with a high incidence of COPD , and may be one way of identifying smokers with COPD in the early stages In general practice , diagnosis of chronic obstructive pulmonary disease ( COPD ) is hampered by underpresentation . A substantial proportion of subjects experiencing respiratory complaints do not consult their general practitioner ( GP ) . In this study , the relationship between disease-specific quality of life and presentation of respiratory symptoms to a GP is investigated . A r and om sample from the general population ( undiagnosed subjects ) was screened for symptoms and objective signs of COPD ( n=1,155 ) . The lung function of subjects with symptoms of COPD was monitored for 6 months . During this period , 48 new COPD patients with a persistently reduced lung function ( forced expiratory volume in one second ( FEV1 ) less than or equal to the predicted value minus 2 SD ) were detected . A disease-specific quality -of-life question naire ( chronic respiratory question naire ( CRQ ) ) was administered and clinical and GP consultation data were collected . Multivariate analysis showed that quality -of-life impairments due to dyspnoea and fatigue and variability in lung function ( bronchial hyperresponsiveness , reversibility and peak expiratory flow rate variability ) were related to medical consultation . Only 31 % of the newly detected patients reported that they had ever visited their GP for respiratory complaints . A similarly low percentage was found in the rest of the sample ( 26 % ) . It is concluded that the mere presence of respiratory symptoms or a ( gradually ) reduced lung function is insufficient reason for patients to seek medical help . Subjects are more likely to consult their general practitioner once their quality of everyday life is affected or they experience variability in lung function BACKGROUND Chronic obstructive pulmonary disease ( COPD ) is a major cause of morbidity and mortality . However , much of the disease burden remains undiagnosed . AIM To compare the yield and cost effectiveness of two COPD case-finding approaches in primary care . DESIGN AND SETTING Pilot r and omised controlled trial in two general practice s in the West Midl and s , UK . METHOD A total of 1634 ever-smokers aged 35 - 79 years with no history of COPD or asthma were r and omised into either a ' targeted ' or ' opportunistic ' case-finding arm . Respiratory question naires were posted to patients in the ' targeted ' arm and provided to patients in the ' opportunistic ' arm at routine GP appointments . Those reporting at least one chronic respiratory symptom were invited for spirometry . COPD was defined as pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC)<0.7 and FEV1<80 % of predicted . Primary outcomes were the difference in the proportion of patients diagnosed with COPD and the cost per case detected . RESULTS Twenty-six per cent ( 212/815 ) in the ' targeted ' and 13.6 % ( 111/819 ) in the ' opportunistic ' arm responded to the question naire and 78.3 % ( 166/212 ) and 73.0 % ( 81/111 ) , respectively , reported symptoms ; 1.2 % ( 10/815 ) and 0.7 % ( 6/819 ) of patients in the ' targeted ' and ' opportunistic ' arms were diagnosed with COPD ( difference in proportions = 0.5 % [ 95 % confidence interval { CI } = -0.5 % to 3.08 % ] ) . Over a 12-month period , the ' opportunistic ' case-finding yield could be improved to 1.95 % ( 95 % CI = 1.0 % to 2.9 % ) . The cost-per case detected was £ 424.56 in the ' targeted ' and £ 242.20 in the ' opportunistic ' arm . CONCLUSION Opportunistic case finding may be more effective and cost effective than targeting patients with a postal question naire alone . A larger r and omised controlled trial with adequate sample size is required to test this The Global Initiative for Chronic Obstructive Lung Disease ( GOLD ) has defined stage 1 chronic obstructive pulmonary disease ( COPD ) as forced expiratory volume in one second/forced vital capacity (FEV1/FVC)% < 70 % and a FEV1 % predicted of > 80 % . Stage 2 has been defined as FEV1/FVC < 70 % and a FEV1 % pred of < 80 % . The authors examined the extent of COPD misdiagnosis using this definition in healthy , never-smoker , asymptomatic adults aged > 70 yrs in Bergen , Norway . A respiratory question naire was mailed to a r and om sample of 2,871 persons aged>70 yrs . In a r and om , well-defined subgroup of 208 never-smoker respondents with no current respiratory disease and significant dyspnoea or heart disease/hypertension complicated with dyspnoea , 71 were able to perform an acceptable spirometry . Approximately 35 % of these healthy , elderly never-smokers had an FEV1/FVC% of < 70 % and would be classified as having at least a stage 1 COPD . This percentage increased with age and in those aged > 80 yrs ∼50 % would be classified as having COPD and approximately one-third would have an FEV1 of < 80 % pred ( stage 2 COPD ) . The estimated 5th percentile of FEV1 was consistently < 80 % pred . The Global Initiative for Chronic Obstructive Lung Disease criteria will probably lead to a significant degree of over-diagnosis of chronic obstructive pulmonary disease in those aged > 70 yrs . The criteria used to define the various stages of chronic obstructive pulmonary disease need to be age-specific The aim of the present study was to determine the external validity of a recently developed question naire for the identification of patients at increased risk of airflow limitation in smokers from the general population in the provinces of Dutch and Belgian Limburg ( regions surrounding Maastricht , the Netherl and s ) . As part of a study on the early detection of airflow limitation and subsequent smoking cessation treatment ( International St and ard R and omised Controlled Trial Number : 64481813 ) , the recently developed chronic obstructive pulmonary disease ( COPD ) diagnostic question naire was used in current smokers aged 40–70 yrs , with a smoking history of ≥10 pack-yrs , who reported one or more respiratory symptom ( cough , sputum production or dyspnoea ) , but who had no diagnosis of a respiratory disease ( COPD or asthma ) .  Spirometry performed according to American Thoracic Society/European Respiratory Society criteria served as a reference test . Of the 676 subjects who entered the analyses , 398 showed normal lung function and 278 had a diagnosis of COPD ( post-bronchodilator forced expiratory volume in one second/forced vital capacity of < 0.70 ) . The ability of the COPD diagnostic question naire to discriminate between subjects with and without COPD was poor ( area under the receiver operating characteristic curve of 0.65 ) . In a high-risk population consisting of middle-aged current smokers with a smoking history of ≥10 pack-yrs , the chronic obstructive pulmonary disease diagnostic question naire is probably not useful as a diagnostic tool for the identification of patients with an increased risk of airflow limitation BACKGROUND Chronic obstructive pulmonary disease ( COPD ) is a leading cause of disability , hospital admission and premature mortality , but is often undiagnosed . This study assessed the effectiveness , feasibility and acceptability of COPD case finding by practice nurses performing spirometry on patients identified as being at risk of developing COPD . METHODS Practice nurses were trained in spirometry .  From four general practice s , 1010 patients were identified who were aged 40 - 80 years and current or ex-smokers . Four hundred were r and omised to receive a written invitation to attend a case finding appointment with the practice nurse , including spirometry . RESULTS Seventy-nine patients attended , 16 ( 20.3 % of attendees ) had COPD diagnosed on spirometry ; practice nurses correctly identified 10 of the 16 , but also incorrectly identified a further six patients as having COPD . One patient in the usual care group was diagnosed with COPD , but this was not confirmed on spirometry . DISCUSSION This study confirmed that COPD is underdiagnosed , with 20 % of those at risk and attending for screening having COPD . The search strategy successfully identified patients at risk . Further training in spirometry would be required for practice nurses to increase the accuracy of the diagnoses . The opportunity cost would require consideration . The acceptability to patients is also an issue , this may be related to the recruitment method or the intervention . This study also does not answer whether earlier diagnosis in these patients leads to any change in outcomes Background : The burden of chronic obstructive pulmonary disease ( COPD ) is high . Health benefits can be gained in primary care by early detection and preventive measures . Aims : To compare the effectiveness of two strategies for population -based early detection of COPD , taking into account different socioeconomic status ( SES ) setting s. Methods : Practice s were r and omised on strategy and stratified on SES setting . The Respiratory Health Screening Question naire ( RHSQ ) was distributed to all participants . In the practice -managed condition , the practice was responsible for the whole procedure , while in the patient-managed condition , patients were responsible for calculating their RHSQ risk score and applying for a spirometry test . The main outcome measure was the rate of COPD diagnoses after screening . Results : More new COPD patients  were detected in the practice -managed condition ( 36 % ) than in the patient-managed condition ( 18 % ) . In low SES practice s , more high-risk patients were found ( 16 % ) than in moderate-to-high SES 
    Output:
    
Overall , any approach identified more undiagnosed COPD compared with usual care .
Targeting those at higher risk ( e.g. , smokers ) and pre-screening ( e.g. , using question naires ) is likely to increase the yield .