Prognostic Value of the Six-Second Spirometry in Patients with Chronic Obstructive Pulmonary Disease: A Cohort Study.
BACKGROUND
The six-second spirometry has been proposed as an alternative to diagnose airflow limitation, although its prognostic value in patients with chronic obstructive pulmonary disease (COPD) remains unknown. The purpose of this study was to determine the prognostic value of the postbronchodilator forced expiratory volume in 1 second (FEV1)/forced expiratory volume in 6 seconds (FEV6) ratio and FEV6 in COPD patients.


RESULTS
The study population consisted of 2,614 consecutive stable patients with COPD. The patients were monitored for an average period of 4.3 years regarding mortality, hospitalizations by COPD exacerbations, diagnosis of lung cancer, and annual lung function decline. The overall rate of death was 10.7 (95%CI: 8.7-12.7) per 1000 person-years. In addition to male gender, age and comorbidity, FEV6 (hazard ratio [HR]: 0.981, 95%CI: 0.968-0.003) and FEV1/FEV6 quartiles (lowest quartile (<74% pred.): HR 3.558, 95%CI: 1.752-7.224; and second quartile (74-84% pred.): HR 2.599, 95%CI: 1.215-5.561; versus best quartile (>0.89% pred.)) were independently associated with mortality, whereas FEV1 was not retained in the model. 809 patients (30.9%) had at least one hospital admission due to COPD exacerbation. In addition to sex, age, smoking and comorbidity, FEV1 and FEV1/FEV6 quartiles were independent risk factors of hospitalization. FEV6 was the only spirometric parameter independently related with lung function annual decline, while the FEV6 and FEV1/FEV6 quartiles were independent risk factors for lung cancer.


CONCLUSIONS
In a general COPD outpatient population, airflow obstruction assessed by the FEV1/FEV6 is an independent risk factor for both death and hospitalization.
Unidad de Neumología. Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain.
Eva
E
Prats
Servicio de Urgencias. Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain.
Elena
E
Tejero
Servicio de Urgencias. Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain.
Paloma
P
Pardo
Servicio de Urgencias. Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain.
Adelaida
A
Gavilán
Servicio de Neumología. Hospital Universitario La Paz, IdiPAZ, Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain.
Raúl
R
Galera
Unidad de Neumología. Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain.
José Ramón
JR
Donado
Unidad de Neumología. Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain.
Miguel Ángel
MÁ
Racionero
Servicio de Neumología. Hospital Universitario La Paz, IdiPAZ, Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain.
Raquel
R
Casitas
Servicio de Medicina Interna. Hospital Universitario de Fuenlabrada, Fuenlabrada, Madrid, Spain.
Antonio
A
Zapatero
Servicio de Neumología. Hospital Universitario La Paz, IdiPAZ, Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain; Universidad Autónoma de Madrid, Madrid, Spain.
Francisco
F
García-Río
D000328:Adult; D015331:Cohort Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality / Q000503:physiopathology*; D012307:Risk Factors; D013147:Spirometry / Q000379:methods*; D014797:Vital Capacity / Q000502:physiology*