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Diagnostic accuracy of pre-bronchodilator FEV1/FEV6 from microspirometry to detect airflow obstruction in primary care: a randomised cross-sectional study.

van den Bemt L, Wouters BC, Grootens J, Denis J, Poels PJ, Schermer TR - NPJ Prim Care Respir Med (2014)

Bottom Line: A pre-BD FEV1/FEV6 value <0.73 as measured with the PiKo-6 microspirometer was compared with a post-BD FEV1/FVC (forced vital capacity) <0.70 and FEV1/FVC<lower limit of normal (LLN) from diagnostic spirometry.One hundred and four subjects were analysed (59.6% males, 42.3% current smokers).In all, 18% of positive microspirometry results were not confirmed by a post-BD FEV1/FVC <0.70 and 44% of tests were false positive compared with the LLN criterion for airflow obstruction.

View Article: PubMed Central - PubMed

Affiliation: Department of Primary and Community Care, Radboud University Medical Center, Nijmegen, The Netherlands.

ABSTRACT

Background: Forced expiratory volume in 1s/forced expiratory volume in 6 s ( FEV1/FEV6) assessment with a microspirometer may be useful in the diagnostic work up of subjects who are suspected of having COPD in primary care.

Aim: To determine the diagnostic accuracy of a negative pre-bronchodilator (BD) microspirometry test relative to a full diagnostic spirometry test in subjects in whom general practitioners (GPs) suspect airflow obstruction.

Methods: Cross-sectional study in which the order of microspirometry and diagnostic spirometry tests was randomised. Study subjects were (ex-)smokers aged ≥50 years referred for diagnostic spirometry to a primary care diagnostic centre by their GPs. A pre-BD FEV1/FEV6 value <0.73 as measured with the PiKo-6 microspirometer was compared with a post-BD FEV1/FVC (forced vital capacity) <0.70 and FEV1/FVC

Results: One hundred and four subjects were analysed (59.6% males, 42.3% current smokers). Negative predictive values from microspirometry for airflow obstruction based on the fixed and LLN cut-off points were 94.4% (95% confidence interval (CI), 86.4-98.5) and 96.3% (95% CI, 88.2-99.3), respectively. In all, 18% of positive microspirometry results were not confirmed by a post-BD FEV1/FVC <0.70 and 44% of tests were false positive compared with the LLN criterion for airflow obstruction.

Conclusions: Pre-bronchodilator microspirometry seems to be able to reliably preselect patients for further assessment of airflow obstruction by means of regular diagnostic spirometry. However, use of microspirometry alone would result in overestimation of airflow obstruction and should not replace regular spirometry when diagnosing COPD in primary care.

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Related in: MedlinePlus

Flow chart of subject recruitment and selection.
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fig1: Flow chart of subject recruitment and selection.

Mentions: A total of 121 subjects were recruited (see Figure 1), of whom 111 subjects were eligible for the study. Of them, six failed to complete the microspirometry test, and diagnostic spirometry data were incomplete for one patient. Valid diagnostic spirometry and microspirometry data were available for 104 study participants. Table 1 shows baseline and clinical characteristics of the subjects. Airflow obstruction (i.e., post-BD FEV1/FVC <0.7) was observed in 44 subjects (42.3%), with most of them (88.6%) being classified as having mild to moderate airflow obstruction (see Table 1). Forty-three per cent of subjects with no airflow obstruction used prescribed respiratory medication. Twelve subjects (11.5%) met the criteria for a reversible airflow obstruction.


Diagnostic accuracy of pre-bronchodilator FEV1/FEV6 from microspirometry to detect airflow obstruction in primary care: a randomised cross-sectional study.

van den Bemt L, Wouters BC, Grootens J, Denis J, Poels PJ, Schermer TR - NPJ Prim Care Respir Med (2014)

Flow chart of subject recruitment and selection.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4373403&req=5

fig1: Flow chart of subject recruitment and selection.
Mentions: A total of 121 subjects were recruited (see Figure 1), of whom 111 subjects were eligible for the study. Of them, six failed to complete the microspirometry test, and diagnostic spirometry data were incomplete for one patient. Valid diagnostic spirometry and microspirometry data were available for 104 study participants. Table 1 shows baseline and clinical characteristics of the subjects. Airflow obstruction (i.e., post-BD FEV1/FVC <0.7) was observed in 44 subjects (42.3%), with most of them (88.6%) being classified as having mild to moderate airflow obstruction (see Table 1). Forty-three per cent of subjects with no airflow obstruction used prescribed respiratory medication. Twelve subjects (11.5%) met the criteria for a reversible airflow obstruction.

Bottom Line: A pre-BD FEV1/FEV6 value <0.73 as measured with the PiKo-6 microspirometer was compared with a post-BD FEV1/FVC (forced vital capacity) <0.70 and FEV1/FVC<lower limit of normal (LLN) from diagnostic spirometry.One hundred and four subjects were analysed (59.6% males, 42.3% current smokers).In all, 18% of positive microspirometry results were not confirmed by a post-BD FEV1/FVC <0.70 and 44% of tests were false positive compared with the LLN criterion for airflow obstruction.

View Article: PubMed Central - PubMed

Affiliation: Department of Primary and Community Care, Radboud University Medical Center, Nijmegen, The Netherlands.

ABSTRACT

Background: Forced expiratory volume in 1s/forced expiratory volume in 6 s ( FEV1/FEV6) assessment with a microspirometer may be useful in the diagnostic work up of subjects who are suspected of having COPD in primary care.

Aim: To determine the diagnostic accuracy of a negative pre-bronchodilator (BD) microspirometry test relative to a full diagnostic spirometry test in subjects in whom general practitioners (GPs) suspect airflow obstruction.

Methods: Cross-sectional study in which the order of microspirometry and diagnostic spirometry tests was randomised. Study subjects were (ex-)smokers aged ≥50 years referred for diagnostic spirometry to a primary care diagnostic centre by their GPs. A pre-BD FEV1/FEV6 value <0.73 as measured with the PiKo-6 microspirometer was compared with a post-BD FEV1/FVC (forced vital capacity) <0.70 and FEV1/FVC

Results: One hundred and four subjects were analysed (59.6% males, 42.3% current smokers). Negative predictive values from microspirometry for airflow obstruction based on the fixed and LLN cut-off points were 94.4% (95% confidence interval (CI), 86.4-98.5) and 96.3% (95% CI, 88.2-99.3), respectively. In all, 18% of positive microspirometry results were not confirmed by a post-BD FEV1/FVC <0.70 and 44% of tests were false positive compared with the LLN criterion for airflow obstruction.

Conclusions: Pre-bronchodilator microspirometry seems to be able to reliably preselect patients for further assessment of airflow obstruction by means of regular diagnostic spirometry. However, use of microspirometry alone would result in overestimation of airflow obstruction and should not replace regular spirometry when diagnosing COPD in primary care.

Show MeSH
Related in: MedlinePlus