Authors: (including presenting author): :
Leung CC(1), Leung TF(1), Li YC(1), Chen CXR(1)
Affiliation: :
(1)Department of Family Medicine and General Outpatient Patient Clinics, Queen Elizabeth Hospital
Introduction: :
WHO estimated COPD accounted for 5% of all deaths in 2015 in the world and predicted that it would become number 3 killer by 2020. In Hong Kong, there were >1300 deaths due to COPD in 2016 and almost 30,000 public hospital admissions in the same year. There is a high prevalence of underdiagnosed COPD in general populations as well as in primary care. COPD is often underdiagnosed probably because of the underutilization of spirometry due to time constraint, the complexity of the tool and lack of trained personnel.
The handheld COPD-6™ measures forced expiratory volume ratio at 1 and 6 seconds (FEV1/FEV6) has been used in some countries such as Australia, Spain, Korea and Japan as an alternative to standard spirometry in diagnosing COPD.
Objectives: :
Objects of this study are to validate the diagnostic accuracy of COPD-6™ in the Chinese population in public primary settings against the spirometry as the gold standard and to explore the best FEV1/FEV6 cut-off in our locality.
Methodology: :
This is a prospective validation study performed in general outpatient clinics(GOPCs) in Kowloon Central Cluster from Jan 2018 to June 2018. Chinese individuals aged 40 or above, current smoker or ex-smoker, were recruited to do the COPD-6™ and standard spirometry separately. The correlations between FEV1/FEV6 readings and post-bronchodilator spirometric FEV1/FVC readings were assessed by Pearson correlation analysis. Standard validation measures, including sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated to find out the best FEV1/FEV6 cut-off.
Result & Outcome: :
Totally 106 out of 120 subjects’ data were valid for data analysis. FEV1/FEV6 readings correlated well with post-bronchodilator FEV1/FVC (R coefficient =0.725, p< 0.001). COPD-6™ showed good diagnostic accuracy with the area under the Receiver Operating Characteristic curve 0.916 (95% Confidence interval 0.86 to 0.97). FEV1/FEV6< 0.69 was identified to be the best cut-off value with an excellent sensitivity of 87% and specificity of 90%. In conclusion, COPD-6™ demonstrated high accuracy in detecting COPD in the primary care setting. FEV1/FEV6< 0.69 is recommended to be the best cut-off for case detection. This promising result is helpful in implementing the hand-held COPD-6™ as a screening tool among high-risk individuals to actively detect COPD in primary care setting.
