TY - JOUR

T1 - Impact of diagnostic criteria on the prevalence of COPD

AU - Çolak, Yunus

AU - Løkke, Anders

AU - Marott, Jacob Louis

AU - Lange, Peter

AU - Vestbo, Jørgen

N1 - © 2012 Blackwell Publishing Ltd.

PY - 2012

Y1 - 2012

N2 - INTRODUCTION: The reduction in the ratio between forced expiratory volume in 1¿s (FEV(1) ) and forced vital capacity (FVC) is used for the diagnosis of chronic obstructive pulmonary disease (COPD). The choice between a simple fixed cut-off ratio (FEV(1) /FVC <0.70) and the use of lower limit of normal (LLN) is eagerly discussed. The aim of this paper was to examine the impact of these twodiagnostic measures on the prevalence of COPD using data from the fourth examination of The Copenhagen City Heart Study (CCHS4).MATERIALS AND METHODOLOGY: A total of 6237 subjects participated in CCHS4 from 2001 to 2003. Asymptomatic, healthy never-smokers of all ages with adequate information from questionnaires and spirometry were used tocalculate LLN.RESULTS: LLN was declining with increasing age and height. If LLN was used as the correct diagnostic criterion, under- and over-diagnosis among men were 0.4% and 7.0%, respectively, and for women 2.0% and 1.4%, respectively, when using the fixed ratio. Over-diagnosis among men was reduced from 7.0% to 3.0% by changing the fixed cut-off ratio to FEV(1) /FVC <0.65 for subjects olderthan 65 years. Among women, however, this adjustment led to an increase in under-diagnosis from 2.0% to 5.7%. Most participants with FEV(1) /FVC <0.70 but >LLN had well-preserved FEV(1) .CONCLUSION:Using the fixed ratio for diagnosing COPD in an epidemiological setting results in a higher prevalence than if the LLN is used. Time seems ripe for studying if the same is seen when diagnosing COPD in the clinical setting.

AB - INTRODUCTION: The reduction in the ratio between forced expiratory volume in 1¿s (FEV(1) ) and forced vital capacity (FVC) is used for the diagnosis of chronic obstructive pulmonary disease (COPD). The choice between a simple fixed cut-off ratio (FEV(1) /FVC <0.70) and the use of lower limit of normal (LLN) is eagerly discussed. The aim of this paper was to examine the impact of these twodiagnostic measures on the prevalence of COPD using data from the fourth examination of The Copenhagen City Heart Study (CCHS4).MATERIALS AND METHODOLOGY: A total of 6237 subjects participated in CCHS4 from 2001 to 2003. Asymptomatic, healthy never-smokers of all ages with adequate information from questionnaires and spirometry were used tocalculate LLN.RESULTS: LLN was declining with increasing age and height. If LLN was used as the correct diagnostic criterion, under- and over-diagnosis among men were 0.4% and 7.0%, respectively, and for women 2.0% and 1.4%, respectively, when using the fixed ratio. Over-diagnosis among men was reduced from 7.0% to 3.0% by changing the fixed cut-off ratio to FEV(1) /FVC <0.65 for subjects olderthan 65 years. Among women, however, this adjustment led to an increase in under-diagnosis from 2.0% to 5.7%. Most participants with FEV(1) /FVC <0.70 but >LLN had well-preserved FEV(1) .CONCLUSION:Using the fixed ratio for diagnosing COPD in an epidemiological setting results in a higher prevalence than if the LLN is used. Time seems ripe for studying if the same is seen when diagnosing COPD in the clinical setting.

U2 - 10.1111/crj.12007.

DO - 10.1111/crj.12007.

M3 - Journal article

VL - 7

SP - 297

EP - 303

JO - Clinical Respiratory Journal

JF - Clinical Respiratory Journal

SN - 1752-6981

IS - 3

ER -