Impact of body mass index on the predictive capacity of the COPD-6 device in the detection of airflow obstruction.
BACKGROUND AND OBJECTIVE
The portable COPD-6 device has been validated as a screening tool for airflow obstruction through the quantification of the FEV1/FEV6 ratio. To date, however, the impact of body mass index (BMI) on its ability to predict airflow obstruction has not been evaluated. The aim of the study was to assess the predictive ability of COPD-6 to detect airflow obstruction based on the patient's BMI.


MATERIAL AND METHOD
A prospective and open cohort study in which 223 subjects who underwent conventional spirometry and COPD-6 were included. The area under the curve ROC (AUC) of FEV1/FEV6 was analysed in the detection of obstruction for all patients in addition to BMI (BMI<30kg/m2 and BMI≥30kg/m2). Sensitivity and specificity, negative and positive predictive value as well as likelihood ratio were calculated to determine the cut-off point of COPD-6 FEV1/FEV6 ratio with greater predictive capacity.


RESULTS
The COPD-6 allows ruling out airflow obstruction with AUC of the estimated ROC curve of 88% (95% CI 83-93). The cut-off point FEV1/FEV6 of 0.74-0.76 shows the best predictive capacity. However, this capacity is altered according to BMI with an increase in false positives in subjects with BMI≥30kg/ m2 when using the same cut-off point for the whole sample.


CONCLUSION
The choice of cut-off point FEV1/FEV6 for the detection of obstruction should be adjusted to the patient's BMI.
['Figueira Gonçalves|Juan Marco|JM|', 'Pérez Méndez|Lina Inmaculada|LI|', 'Guzmán Sáenz|Cristina|C|', 'Díaz Pérez|David|D|', 'Viña Manrique|Pedro|P|', 'Pedrero García|Arturo José|AJ|']
D000328:Adult D000368:Aged D019540:Area Under Curve D015992:Body Mass Index D003430:Cross-Sectional Studies D005260:Female D005541:Forced Expiratory Volume D006801:Humans D008297:Male D008875:Middle Aged D011237:Predictive Value of Tests D011446:Prospective Studies D029424:Pulmonary Disease, Chronic Obstructive D012372:ROC Curve D012680:Sensitivity and Specificity D013147:Spirometry
Body mass index Spirometry Chronic obstructive pulmonary disease Enfermedad pulmonar obstructiva crónica Espirometría FEV(6) Índice de masa corporal