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

Franco-Marina F, Fernandez-Plata R, Torre-Bouscoulet L, García-Sancho C, Sanchez-Gallen E, Martinez D, Perez-Padilla R, Study Te - NPJ Prim Care Respir Med (2014)

Bottom Line: Underdiagnosis of chronic obstructive pulmonary disease (COPD) in primary care can be improved by a more efficient screening strategy.We analysed two related Mexico City cross-sectional samples.A three-step screening strategy for COPD substantially reduces the need for spirometry testing when only a COPD scale is used for screening.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, National Institute of Respiratory Diseases, Mexico City, Mexico.

ABSTRACT

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.

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Related in: MedlinePlus

Projected percent of the total population positive to the COPD scale, combined positive predictive value and percent of the total population requiring confirmatory spirometry under serial screening with COPD scale and 6-SS, calculated for a range of COPD prevalence values (with 3 COPD definitions, graph a, b, c). Grey lines around means correspond to 95% confidence intervals.
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fig5: Projected percent of the total population positive to the COPD scale, combined positive predictive value and percent of the total population requiring confirmatory spirometry under serial screening with COPD scale and 6-SS, calculated for a range of COPD prevalence values (with 3 COPD definitions, graph a, b, c). Grey lines around means correspond to 95% confidence intervals.

Mentions: Figure 5 summarises several performance parameters of the serial testing with a range of prevalence values which are similar to those observed for the five Latin American cities included in the PLATINO study. Between 35 and 48% would not proceed to the second step. If those positive on the COPD scale performed a 6-second spirometry test, the percentage of the total population requiring all three screening steps including confirmatory spirometry would range from 10 to 20%.


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

Franco-Marina F, Fernandez-Plata R, Torre-Bouscoulet L, García-Sancho C, Sanchez-Gallen E, Martinez D, Perez-Padilla R, Study Te - NPJ Prim Care Respir Med (2014)

Projected percent of the total population positive to the COPD scale, combined positive predictive value and percent of the total population requiring confirmatory spirometry under serial screening with COPD scale and 6-SS, calculated for a range of COPD prevalence values (with 3 COPD definitions, graph a, b, c). Grey lines around means correspond to 95% confidence intervals.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4373258&req=5

fig5: Projected percent of the total population positive to the COPD scale, combined positive predictive value and percent of the total population requiring confirmatory spirometry under serial screening with COPD scale and 6-SS, calculated for a range of COPD prevalence values (with 3 COPD definitions, graph a, b, c). Grey lines around means correspond to 95% confidence intervals.
Mentions: Figure 5 summarises several performance parameters of the serial testing with a range of prevalence values which are similar to those observed for the five Latin American cities included in the PLATINO study. Between 35 and 48% would not proceed to the second step. If those positive on the COPD scale performed a 6-second spirometry test, the percentage of the total population requiring all three screening steps including confirmatory spirometry would range from 10 to 20%.

Bottom Line: Underdiagnosis of chronic obstructive pulmonary disease (COPD) in primary care can be improved by a more efficient screening strategy.We analysed two related Mexico City cross-sectional samples.A three-step screening strategy for COPD substantially reduces the need for spirometry testing when only a COPD scale is used for screening.

View Article: PubMed Central - PubMed

Affiliation: Department of Epidemiology, National Institute of Respiratory Diseases, Mexico City, Mexico.

ABSTRACT

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.

Show MeSH
Related in: MedlinePlus