Six-second spirometry for detection of airway obstruction: a population-based study in Austria

Validity of the Handheld Expiratory Flowmeter for COPD Screening in the Primary Care Setting of China

Purpose

The use of simple and affordable screening tools for chronic obstructive pulmonary disease (COPD) is limited. We aimed to assess the validity of a handheld expiratory flowmeter (Vitalograph Ltd., COPD-6^®, Ireland) for COPD screening in Chinese primary care settings.

Methods

In our cross-sectional study, subjects were randomly selected in eight primary care settings. Tests with the handheld expiratory flowmeter and the conventional spirometry were sequentially performed on all participants. The correlation between the handheld expiratory flowmeter and the conventional spirometry was determined. Validity was determined by the area under the receiver operator characteristic curve (AUC) of the forced expiratory volume in one second (FEV₁)_/forced expiratory volume in six seconds (FEV₆) that used to detect airway obstruction. The sensitivity, specificity, predictive values, and likelihood ratio were calculated according to different FEV₁/FEV₆ cut-off points.

Results

A total of 229 subjects (15.4%) were diagnosed with airflow limitation by conventional spirometry. FEV₁, FEV₆, and FEV₁/FEV₆ measured by the handheld expiratory flowmeter were correlated with FEV₁, FVC, and FEV₁/FVC measured by the conventional spirometry (r=0.889, 0.835 and 0.647, p<0.001), respectively. AUC of the FEV₁/FEV₆ to determine airflow obstruction was 0.857 (95% CI: 0.826 to 0.888). No significant difference of AUC was observed between the symptomatic group and the asymptomatic group (AUC=0.869 vs 0.843, P=0.425). A similar phenomenon was found in the AUC of smokers and never-smokers (AUC=0.862 vs 0.840; P=0.515). The cut-off point for FEV₁/FEV₆ was 0.77 and the corresponding sensitivity and specificity were 71.2% and 89.8%, respectively.

Conclusion

The handheld expiratory flowmeter might be used as a screening device for COPD in Chinese primary care settings.

Accuracy of Vitalograph lung monitor as a screening test for COPD in primary care

Microspirometry may be useful as the second stage of a screening pathway among patients reporting respiratory symptoms. We assessed sensitivity and specificity of the Vitalograph® lung monitor compared with post-bronchodilator confirmatory spirometry (ndd Easy on-PC) among primary care chronic obstructive pulmonary disease (COPD) patients within the Birmingham COPD cohort. We report a case-control analysis within 71 general practices in the UK. Eligible patients were aged ≥40 years who were either on a clinical COPD register or reported chronic respiratory symptoms on a questionnaire. Participants performed pre- and post-bronchodilator microspirometry, prior to confirmatory spirometry. Out of the 544 participants, COPD was confirmed in 337 according to post-bronchodilator confirmatory spirometry. Pre-bronchodilator, using the LLN as a cut-point, the lung monitor had a sensitivity of 50.5% (95% CI 45.0%, 55.9%) and a specificity of 99.0% (95% CI 96.6%, 99.9%) in our sample. Using a fixed ratio of FEV1/FEV6 < 0.7 to define obstruction in the lung monitor, sensitivity increased (58.8%; 95% CI 53.0, 63.8) while specificity was virtually identical (98.6%; 95% CI 95.8, 99.7). Within our sample, the optimal cut-point for the lung monitor was FEV1/FEV6 < 0.78, with sensitivity of 82.8% (95% CI 78.3%, 86.7%) and specificity of 85.0% (95% CI 79.4%, 89.6%). Test performance of the lung monitor was unaffected by bronchodilation. The lung monitor could be used in primary care without a bronchodilator using a simple ratio of FEV1/FEV6 as part of a screening pathway for COPD among patients reporting respiratory symptoms.

Joint Indian Chest Society-National College of Chest Physicians (India) guidelines for spirometry

Although a simple and useful pulmonary function test, spirometry remains underutilized in India. The Indian Chest Society and National College of Chest Physicians (India) jointly supported an expert group to provide recommendations for spirometry in India. Based on a scientific grading of available published evidence, as well as other international recommendations, we propose a consensus statement for planning, performing and interpreting spirometry in a systematic manner across all levels of healthcare in India. We stress the use of standard equipment, and the need for quality control, to optimize testing. Important technical requirements for patient selection, and proper conduct of the vital capacity maneuver, are outlined. A brief algorithm to interpret and report spirometric data using minimal and most important variables is presented. The use of statistically valid lower limits of normality during interpretation is emphasized, and a listing of Indian reference equations is provided for this purpose. Other important issues such as peak expiratory flow, bronchodilator reversibility testing, and technician training are also discussed. We hope that this document will improve use of spirometry in a standardized fashion across diverse settings in India.

The accuracy of a handheld "disposable pneumotachograph device" in the spirometric diagnosis of airway obstruction in a Chinese population

Background and aim

It is desirable to facilitate the use of an affordable, reliable, and portable spirometer, for earlier diagnosis of COPD in China, particularly in rural areas. The aim of this study was to assess the agreement of a handheld "disposable pneumotachograph" (D-PNEU) spirometer with the gold standard spirometer and to evaluate its diagnostic accuracy of spirometric classification of airflow obstruction.

Subjects and methods

A total of 241 adult Chinese subjects ranging from healthy to those with mixed levels of pulmonary disease performed spirometry in a conventional body plethysmograph, and using a D-PNEU device in randomized order. The three best spirometric tests were recorded for comparative analysis. A Bland-Altman graph was created to assess the agreement between devices. Using FEV₁/FVC <70% as the "gold standard" for obstruction, the accuracy of classifying the severity of airway obstruction for all subjects was assessed. For the specific individuals (n=159) able to exhale for at least 6 seconds, the accuracy of classifying airway obstruction was further assessed. For this purpose, a receiver operating characteristic curve was used to determine an optimal cutoff point of FEV₁/FEV₆ ratio obtained by the D-PNEU device, which matched the global definition of FEV₁/FVC <70% by the traditional spirometer.

Results

The Bland-Altman analysis showed that the between-device agreement for key airflow metrics was within clinically acceptable limits. The D-PNEU device had 87.1% accuracy in the classification of severity of obstruction in all 241 subjects, when using FEV₁/FVC<70% as the "gold standard" for both devices. The D-PNEU device had 93.7% accuracy in the 159 individuals able to exhale for at least 6 seconds, when a cutoff point of FEV₁/FEV₆ was 74%.

Conclusion

A disposable handheld spirometry device is capable of accurately identifying and quantifying airway obstruction in patients deemed to be at risk, however, caution should be exercised and all available brands should be tested.

Which is the Best Screening Strategy for COPD among Smokers in Primary Care?

We developed a questionnaire to detect cases of chronic obstructive pulmonary disease (COPD) and compared its reliability with other strategies. In order to develop the new questionnaire (COPD screening questionnaire from Terrassa [EGARPOC]) we used data from an epidemiological study on the prevalence of COPD in smokers and calculated the odds ratio for each variable showing significance for the diagnosis of COPD on regression analysis. For comparison among questionnaires and the portable spirometer COPD-6, a cross-sectional multicenter study was performed. The study included 407 smokers or ex-smokers over the age of 40 years with no known diagnosis of COPD, who completed the different questionnaires (EGARPOC, Respiratory Health Screening Questionnaire, COPD-population screener and 2 questions) and underwent spirometry with the COPD-6. We determined the sensitivity, specificity, positive and negative predictive values (S, Sp, PPV and NPV, respectively) and the area under the receiver operating characteristic ROC curve (AUC ROC) of all the questionnaires and the different COPD-6 cut-offs. The prevalence of COPD was 26.3%. The EGARPOC questionnaire showed an S of 81.8%, an Sp of 70.6%, and an NPV of 91.8%; 73.3% of individuals were correctly classified, and the AUC ROC was 0.841. On comparing the questionnaires by the Chi-square test, the 2-question questionnaire showed the worst discrimination; while with an optimal cut-off of forced expiratory volume in one 1 second (FEV₁)/FEV₆ of 0.78, the COPD-6 was significantly better than the questionnaires in the detection of COPD. Using a cut-off of FEV₁/FEV₆ of 0.78 the COPD-6 was found to be the best screening tool for COPD in primary care compared to the questionnaires tested, which did not show differences among them.

Prognostic Value of the Six-Second Spirometry in Patients with Chronic Obstructive Pulmonary Disease: A Cohort Study

BACKGROUND

The six-second spirometry has been proposed as an alternative to diagnose airflow limitation, although its prognostic value in patients with chronic obstructive pulmonary disease (COPD) remains unknown. The purpose of this study was to determine the prognostic value of the postbronchodilator forced expiratory volume in 1 second (FEV1)/forced expiratory volume in 6 seconds (FEV6) ratio and FEV6 in COPD patients.

METHODS AND FINDINGS

The study population consisted of 2,614 consecutive stable patients with COPD. The patients were monitored for an average period of 4.3 years regarding mortality, hospitalizations by COPD exacerbations, diagnosis of lung cancer, and annual lung function decline. The overall rate of death was 10.7 (95%CI: 8.7-12.7) per 1000 person-years. In addition to male gender, age and comorbidity, FEV6 (hazard ratio [HR]: 0.981, 95%CI: 0.968-0.003) and FEV1/FEV6 quartiles (lowest quartile (<74% pred.): HR 3.558, 95%CI: 1.752-7.224; and second quartile (74-84% pred.): HR 2.599, 95%CI: 1.215-5.561; versus best quartile (>0.89% pred.)) were independently associated with mortality, whereas FEV1 was not retained in the model. 809 patients (30.9%) had at least one hospital admission due to COPD exacerbation. In addition to sex, age, smoking and comorbidity, FEV1 and FEV1/FEV6 quartiles were independent risk factors of hospitalization. FEV6 was the only spirometric parameter independently related with lung function annual decline, while the FEV6 and FEV1/FEV6 quartiles were independent risk factors for lung cancer.

CONCLUSIONS

In a general COPD outpatient population, airflow obstruction assessed by the FEV1/FEV6 is an independent risk factor for both death and hospitalization.

PIKO-6® vs. forced spirometry in asthmatic children

BACKGROUND

The PIKO-6® is an electronic device that measures forced expiratory volume at seconds 1 (FEV1) and 6 (FEV6) of a forced vital capacity (FVC) maneuver. This device could aid in diagnosing obstructive respiratory diseases.

OBJECTIVES

To determine the concordance of FEV1, FEV6, and the FEV1/FEV6 quotient achieved with PIKO-6® versus spirometric values from asthmatic patients, and compare results with measures from healthy children.

METHODS

A cross-sectional study with asthmatic and healthy 6-to-14-year-old children, all of whom performed a forced spirometry as well as a PIKO-6® test.

RESULTS

The study included 82 subjects (58 asthmatics, 24 healthy children). Except for the functional parameters, the basal characteristics of the two groups were similar. The concordance correlation coefficient (CCC) for FEV1 was 0.938 (P < 0.001), with 95% limits of agreement of -0.591 to 0.512 L, and an average of differences of -0.040 L. For FEV6, CCC was 0.927 (P < 0.001), and the 95% limits of agreement were -0.751 to 0.598 L with an average of differences of -0.077 L. The concordance analysis and the FEV1 and FEV6 associations were better in children with controlled asthma and healthy subjects, as well as in the post-bronchodilator results.

CONCLUSIONS

The concordance between PIKO-6® and spirometry was lower in patients with partially controlled or uncontrolled asthma compared to controlled or healthy children. The broad limits of agreement show that the FEV1, FEV6, and FEV1/FEV6 obtained with the PIKO-6® are not interchangeable with spirometry results. Longitudinal evaluations of asthma patients are necessary to assess the utility of PIKO-6®.

Efficient screening for COPD using three steps: a cross-sectional study in Mexico City

BACKGROUND

Underdiagnosis of chronic obstructive pulmonary disease (COPD) in primary care can be improved by a more efficient screening strategy.

AIMS

To evaluate a three-step method of screening for COPD consisting of an initial short questionnaire followed by measurement of forced expiratory volume in 1s/forced expiratory volume in 6s (FEV1/FEV6) using an inexpensive pocket spirometer in those with high risk, and diagnostic quality spirometry in those with a low FEV1/FEV6.

METHODS

We analysed two related Mexico City cross-sectional samples. The 2003 Mexico City PLATINO survey (n=542) was used to develop a short questionnaire to determine the risk of COPD and a 2010 survey (n=737) additionally used a pocket spirometer. The discriminatory power of the two instruments was assessed with receiver operator characteristic (ROC) curves using three COPD definitions.

RESULTS

The developed COPD scale included two variables from a simple questionnaire and, in ROC analysis, an area under the curve (AUC) between 0.64 and 0.77 was found to detect COPD. The pocket spirometer had an AUC between 0.85 and 0.88 to detect COPD. Using the COPD scale as a first screening step excluded 35-48% of the total population from further testing at the cost of not detecting 8-18% of those with COPD. Using the pocket spirometer and sending those with a FEV1/FEV6<0.80 for diagnostic quality spirometry is very efficient, and substantially improved the positive predictive value at the cost of not detecting one-third of COPD cases.

CONCLUSIONS

A three-step screening strategy for COPD substantially reduces the need for spirometry testing when only a COPD scale is used for screening.

Reliability of FEV1/FEV6 to diagnose airflow obstruction compared with FEV1/FVC: the PLATINO longitudinal study

QUESTION

A 6-second spirometry test is easier than full exhalations. We compared the reliability of the ratio of the Forced expiratory volume in 1 second/Forced expiratory volume in 6 seconds (FEV₁/FEV₆) to the ratio of the FEV₁/Forced vital capacity (FEV₁/FVC) for the detection of airway obstruction.

METHODS

The PLATINO population-based survey in individuals aged 40 years and over designed to estimate the prevalence of post-Bronchodilator airway obstruction repeated for the same study participants after 5–9 years in three Latin-American cities.

RESULTS

Using the FEV₁/FVC<Lower limit of normal (LLN) index, COPD prevalence apparently changed from 9.8 to 13.2% in Montevideo, from 9.7 to 6.0% in São Paulo and from 8.5 to 6.6% in Santiago, despite only slight declines in smoking prevalence (from 30.8% to 24.3%). These changes were associated with differences in Forced expiratory time (FET) between the two surveys. In contrast, by using the FEV₁/FEV₆ to define airway obstruction, the changes in prevalence were smaller: 9.7 to 10.6% in Montevideo, 8.6 to 9.0% in São Paulo, and 7.5 to 7.9% in Santiago. Changes in the prevalence of COPD with criteria based on FEV₁/FVC correlated strongly with changes in the FET of the tests (R² 0.92) unlike the prevalence based on a low FEV₁/FEV₆ (R² = 0.40).

CONCLUSION

The FEV₁/FEV₆ is a more reliable index than FEV₁/FVC because FVC varies with the duration of the forced exhalation. Reporting FET and FEV₁/FEV₆<LLN helps to understand differences in prevalence of COPD obtained from FEV₁/FVC-derived indices.

Clinical applications of lung function tests: a revisit

The development and clinical application of lung function tests have a long history, and the various components of lung function tests provide very important tools for the clinical evaluation of respiratory health and disease. Spirometry, measurement of the diffusion factor, bronchial provocation tests and forced oscillation techniques have found diverse clinical applications in the diagnosis and monitoring of respiratory diseases, such as chronic obstructive pulmonary disease, interstitial lung diseases and asthma. However, there are some practical issues to be resolved, including the establishment of reference values for individual test parameters and the roles of these tests in preoperative risk assessment and pulmonary rehabilitation. Novel measurements, including negative expiratory pressure, the fraction of exhaled nitric oxide and analysis of exhaled breath condensate, may provide new insights into physiological abnormalities or airway inflammation in respiratory diseases, but their clinical applications need to be further evaluated. The clinical application of lung function tests continues to face challenges, which may be overcome by further improvement of conventional techniques for lung function testing and further specification of new testing techniques.

The diagnostic importance of a reduced FEV1/FEV6

BACKGROUND

On spirometry the FEV(1)/FEV(6) ratio has been advocated as a surrogate for the FEV(1)/FVC. The significance of isolated reductions in either the FEV(1)/FEV(6) or FEV(1)/FVC is not known.

METHODS

First-time adult spirograms (n = 22,837), with concomitant lung volumes (n = 12,040), diffusion (n = 14,154), and inspiratory capacity (n = 12,480) were studied. Four groups were compared. 1) Only FEV(1)/FEV(6) reduced (n = 302). 2) Only FEV(1)/FVC reduced (n = 1158). 3) Both ratios reduced (n = 6593). 4) Both ratios normal (n = 14,784).

RESULTS

In patients with obstructed spirometry (either a reduced FEV(1)/FVC and/or FEV(1)/FEV(6)), 3.8% only had a reduced FEV(1)/FEV(6), while 14.4% only had a reduced FEV(1)/FVC. The mean FEV(1) was lower when both ratios were reduced. The group with only a reduced FEV(1)/FEV(6), compared to only the FEV(1)/FVC reduced, had a lower FEV(1), FVC, BMI, Expiratory Time, and IC (p values < 0.0001). DL(CO) was also lower (p = 0.005), and the FEV(1)/FVC and RV/TLC were higher (p values < 0.0001). When the patients with only a reduced FEV(1)/FEV(6) had a subsequent spirogram, 60% had a reduced FEV(1)/FVC when their mean expiratory times were 3.5 seconds longer. Ninety percent of this group had strong clinical evidence of airways obstruction.

CONCLUSIONS

The FEV(1)/FEV(6) is not as sensitive as the FEV(1)/FVC for diagnosing airways obstruction, but in the presence of a normal FEV(1)/FVC, subjects have greater physiologic abnormalities than when only the FEV(1)/FVC is reduced. The FEV(1)/FEV(6) ratio should not replace the FEV(1)/FVC as the standard for airways obstruction, but there is benefit including this measurement to identify individuals with greater air trapping and diffusion abnormalities.

Detection and prevalence of chronic obstructive pulmonary disease in a cardiovascular clinic: evaluation using a hand held FEV₁/FEV₆ meter and questionnaire

BACKGROUND AND OBJECTIVE

COPD is one of the leading causes of morbidity and mortality worldwide, and its prevalence continues to increase. Although spirometry is indispensable for the diagnosis of COPD, other simple and reliable tools are necessary for screening of COPD because spirometry is not widely available. This study investigated the usefulness of a combination of an electronic FEV₁/FEV₆ meter (PiKo-6) with a COPD questionnaire as a screening method in patients with cardiovascular diseases.

METHODS

The PiKo-6 and the COPD questionnaire of the International Primary Care Airways Group were used to screen patients attending a cardiovascular outpatient clinic. Patients with FEV₁/FEV₆ < 70% were defined as having airflow limitation. Patients diagnosed with airflow limitation underwent spirometry. Using data from the PiKo-6 and the COPD questionnaire, patients were assigned to a COPD group or a non-COPD group. The relationship between PiKo-6 measurements and spirometry was also evaluated.

RESULTS

Among 753 patients, 82 (10.9%) showed airflow limitation when assessed with the PiKo-6. Of these patients, 79 (10.5%) were assigned to the COPD group. FEV₁, FEV₆ and FEV₁/FEV₆, as measured with the PiKo-6, correlated significantly with FEV₁, FVC and FEV₁/FVC, respectively, as measured by spirometry (r = 0.865, 0.751 and 0.57). Among the cardiovascular comorbidities, heart failure and ischaemic heart disease showed slightly stronger associations with airflow limitation (13.8% and 12.5%, respectively).

CONCLUSIONS

Combination of the PiKo-6 with a COPD questionnaire may be a useful and feasible method of identifying undiagnosed COPD patients attending a cardiovascular outpatient clinic.

Spirometry use: detection of chronic obstructive pulmonary disease in the primary care setting

OBJECTIVE

To describe a practical method for family practitioners to stage chronic obstructive pulmonary disease (COPD) by the use of office spirometry.

METHODS

This is a review of the lessons learned from evaluations of the use of office spirometry in the primary care setting to identify best practices using the most recent published evaluations of office spirometry and the analysis of preliminary data from a recent spirometry mass screening project. A mass screening study by the American Association for Respiratory Care and the COPD Foundation was used to identify the most effective way for general practitioners to implement office spirometry in order to stage COPD.

RESULTS

A simple three-step method is described to identify people with a high pre-test probability in an attempt to detect moderate to severe COPD: COPD questionnaire, measurement of peak expiratory flow, and office spirometry. Clinical practice guidelines exist for office spirometry basics for safety, use of electronic peak flow devices, and portable spirometers.

CONCLUSION

Spirometry can be undertaken in primary care offices with acceptable levels of technical expertise. Using office spirometry, primary care physicians can diagnose the presence and severity of COPD. Spirometry can guide therapies for COPD and predict outcomes when used in general practice.

Prognostic value of FEV1/FEV6 in elderly people

BACKGROUND

  The ratio of forced expiratory volume in 1 s and forced expiratory volume in 6 s (FEV1/FEV6) has been proposed as an alternative for FEV1/forced vital capacity (FVC) to diagnose obstructive diseases with less effort during spirometry; however, its prognostic value is unknown. We evaluated whether FEV1/FEV6 is a significant predictor of mortality in elderly subjects and compared its prognostic value with that of FEV1/FVC and FEV1.

METHODS

  One thousand nine hundred and seventy-one subjects, aged >65 years, participated in the population-based SA.R.A. study. During the baseline exam, a multidimensional assessment included spirometry. Vital status was determined during 6 years of follow-up. Association of all-cause, cardio-pulmonary (CP) and non-CP mortality with a low FEV1/FEV6, FEV1/FVC and FEV1 was evaluated.

RESULTS

  Among subjects with both survival data and acceptable spirometry including FEV6, all-cause unadjusted mortality rates were 7·00 and 2·46 per 100 person-years in subjects with FEV1/FEV6 less than and greater than or equal to lower limit of normal (LLN), respectively (mortality rate ratio: 2·84, 95%CI: 2·12-3·84). After adjustment for age, gender, FVC, smoke exposure and main comorbidities, the risk of all-cause mortality remained significantly increased in subjects with FEV1/FEV6<LLN [hazard ratio (HR): 1·87, 95%CI: 1·35-2·58] as well as in subjects with FEV1/FVC<LLN (HR: 2·01, 95%CI: 1·51-2·90) and FEV1<LLN (HR: 2·17, 95%CI: 1·32-3·57). Similar results were found for CP mortality, but not for non-CP mortality.

CONCLUSIONS

  A low FEV1/FEV6 is a significant predictor of mortality in older individuals. Its prognostic value is comparable to that of a low FEV1/FVC and FEV1.

Should FEV1/FEV6 replace FEV1/FVC ratio to detect airway obstruction? A metaanalysis

BACKGROUND

The conventional FEV(1)/FVC test is the "gold standard" to quantitate airway obstruction, but elderly subjects or patients with severe respiratory diseases quite frequently cannot make such an effort. Many studies have investigated the usefulness of FEV(1)/forced expired volume in 6 s (FEV(6)) measurements as an alternative for FEV(1)/FVC for diagnosis of airway obstruction. We conducted a meta-analysis to determine the FEV(1)/FEV(6) substitute for FEV(1)/FVC in the diagnosis of airway obstruction.

METHODS

After a systematic review of all-language studies, sensitivity, specificity, and other measures of accuracy of FEV(1)/FEV(6) in the diagnosis of airway obstruction were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall test performance.

RESULTS

Eleven studies met our inclusion criteria. The summary estimates for FEV(1)/FEV(6) in the diagnosis of airway obstruction in the studies included were as follows: sensitivity, 0.89 (95% confidence interval [CI], 0.83 to 0.93); specificity, 0.98 (95% CI, 0.95 to 0.99); positive likelihood ratio, 45.46 (95% CI, 18.26 to 113.21); negative likelihood ratio, 0.11 (95% CI, 0.08 to 0.17); diagnostic odds ratio, 396.02 (95% CI, 167.32 to 937.31); and diagnostic score, 5.98 (95% CI, 5.12 to 6.84).

CONCLUSIONS

FEV(1)/FEV(6) is a sensitive and specific test for the diagnosis of airway obstruction. FEV(1)/FEV(6) can be used as a valid alternative for FEV(1)/FVC in the diagnosis of airway obstruction.

Office spirometry can improve the diagnosis of obstructive airway disease in primary care setting

INTRODUCTION

Spirometry may reveal pre-clinical abnormal airway function in asymptomatic subjects and allow a better definition of severity in clinically diagnosed asthma and COPD. The hypothesis of this study was that telespirometry might increase the diagnostic accuracy of asthma and COPD.

METHODS

In the Italian "Alliance" study, 638 general practitioners (GPs) were trained to perform telespirometry and were asked to enroll the following categories of subjects: (a) current or ex-smokers without respiratory symptoms; (b) subjects with respiratory symptoms but without a pre-existing diagnosis of asthma or COPD; (c) subjects with a pre-existing clinical diagnosis of asthma; and (d) subjects with a pre-existing clinical diagnosis of COPD. Subjects completed a case report form (CRF) and performed telespirometry in the GP's office. Traces were sent by telephone to a Telespirometry Central Office, where they were interpreted by a pulmonary specialist, according to appropriately defined criteria. The results were returned in real time to the GP.

RESULTS

Overall, 9312 subjects were recruited and 7262 (78%) performed an acceptable telespirometric examination and the CRF. In the asymptomatic group, 340/1437 (24%) of the telespirometries were abnormal (147 with moderate-to-severe airway obstruction, i.e. FEV(1) <80% of predicted). Among symptomatic subjects, 1433/3725 (38%) had abnormal telespirometries (682 with moderate-to-severe obstruction). Of the asthmatic subjects, 336/1285 (26%) had moderate-to-severe airway obstruction, while telespirometry was normal in 184/815 (23%) of the COPD group.

CONCLUSION

Telespirometry, performed in a GP's office, can aid the diagnosis of obstructive airway diseases and could help GPs to better manage airway obstruction.