Is generalization of exhaled CO assessment in primary care helpful for early diagnosis of COPD?
BACKGROUND
COPD is largely under-diagnosed and once diagnosed usually at a late stage. Early diagnosis is thoroughly recommended but most attempts failed as the disease is marginally known and screening marginally accepted. It is a rare cause of concern in primary care and spirometry is not very common. Exhaled carbon monoxide (eCO) is a 5-seconds easy-to-use device dedicated to monitor cigarette smoke consumption. We aimed to assess whether systematic eCO measurement in primary care is a useful tool to improve acceptance for early COPD diagnosis.


METHODS
This was a two-center randomized controlled trial enrolling 410 patients between March and May, 2013. Whatever was the reason of attendance to the clinic, all adults were proposed to measure eCO during randomly chosen days and outcomes were compared between the two different groups of patients (performing and not performing eCO). Primary outcome was the rates of acceptance for COPD screening.


RESULTS
Rate of acceptance for COPD screening was 28% in the eCO group and 26% in the other (P = 0.575). These rates increased to 48 and 51% in smokers (current and former). eCO significantly increased the rate of clinics during which a debate on smoking was initiated (42 vs. 24%, P = 0.001). eCO at 2.5 ppm was the discriminative concentration for identifying active smokers (ROC curve AUC: 0.935). Smoking was the only independent risk factor associated with acceptance for early COPD screening (OR = 364.6 (82.5-901.5) and OR = 78.5 (18.7-330.0) in current and former smokers, respectively) while eCO measurement was not.


CONCLUSIONS
Early COPD diagnosis is a minor cause of concern in primary care. Systematic eCO assessment failed to improve acceptance for early COPD screening.
Département de l'Information Médicale. Hôpital La Colombière, CHU Montpellier, Montpellier, France. nicolas.molinari@inserm.fr.|PhyMedExp, University of Montpellier, INSERM U1046, CNRS UMR 9214, Montpellier, France. nicolas.molinari@inserm.fr.
Nicolas
N
Molinari
Deptartment of Respiratory Disease, CHU Montpellier, Montpellier, France. mathieu.aboubadra@gmail.com.
Mathieu
M
Abou-Badra
Département de l'Information Médicale. Hôpital La Colombière, CHU Montpellier, Montpellier, France. maringregory30@yahoo.fr.
Grégory
G
Marin
Ifremer, UMR EIO241, CIP, BP 7004, 98719, TARAVAO, Tahiti, Polynésie Française. Chin.Long.Ky@ifremer.fr.
Chin-Long
CL
Ky
Département de l'Information Médicale. Hôpital La Colombière, CHU Montpellier, Montpellier, France. noeamador83@gmail.com.
Noemi
N
Amador
Deptartment of Respiratory Disease, CHU Montpellier, Montpellier, France. anso.gamez@gmail.com.
Anne Sophie
AS
Gamez
Deptartment of Respiratory Disease, CHU Montpellier, Montpellier, France. isabelle.vachier@inserm.fr.
Isabelle
I
Vachier
PhyMedExp, University of Montpellier, INSERM U1046, CNRS UMR 9214, Montpellier, France. arnaud01009157@gmail.com.|Deptartment of Respiratory Disease, CHU Montpellier, Montpellier, France. arnaud01009157@gmail.com.
Arnaud
A
Bourdin
D000328:Adult; D000368:Aged; D019540:Area Under Curve; D001944:Breath Tests; D002248:Carbon Monoxide / Q000032:analysis*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D010342:Patient Acceptance of Health Care; D011320:Primary Health Care; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis*; D012372:ROC Curve; D012907:Smoking
D002248:Carbon Monoxide