[Estimation of initial interobserver variability of forced spirometry in the multicenter epidemiological study IBERPOC. Scientific Committee of the IBERPOC study].
To estimate the interobserver variability and degree of agreement for basic spirometric parameters before beginning field work for the IBERPOC Project. Study of agreement between 7 observers (pneumologists) and a gold standard, using a scheme of incomplete balanced and randomized blocks with an equal number of spirometric measurements (n = 3) per patient and an equal number of measurements (n = 9) per observer performed at the same session. The study population consisted of 14 patients with different degrees of air flow obstruction and 7 normal volunteers. Statistically significant differences attributable to subjects (inter-patient variability) were found for the three variables analyzed. Variability attributable to the observer was found for FVC and FEV1 but not for FEV1/FVC. The greatest interobserver differences were found for FEV1, such that 4 of the 7 observers recorded values that were significantly different from the mean (p < 0.05). The differences were less marked for FVC and for the FEV1/FVC ratio, with only 2 observers recording significantly different values for each variable. The high degree of reproducibility as well as the excellent interobserver agreement found in this standardization session provide an a priori guarantee of validity for spirometric measurements and rule out the existence of differential bias in data recorded at the various geographic areas involved in the study.
Gabriel Sánchez
R
R
Unidad de Epidemiología Clínica, Hospital Universitario de la Princesa, Madrid.
Villasante Fernández-Montes
C
C
Pino García
J M
JM
García Río
F
F
Miravitlles
M
M
Jiménez Ruiz
C A
CA
Sobradillo Peña
V
V
D003627:Data Interpretation, Statistical; D005540:Forced Expiratory Flow Rates; D005541:Forced Expiratory Volume; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000175:diagnosis / Q000453:epidemiology*; D015337:Multicenter Studies as Topic; D015588:Observer Variation; D011897:Random Allocation; D013147:Spirometry