Quality control of spirometry in the elderly: The SA.R.A. study

We evaluated the outcome of the spirometry quality control program of the SA.R.A. multicenter project, the aim of which is the multidimensional assessment of asthma and COPD in the elderly (≥ 65 yr). The factors determining this quality were also evaluated. The program was based on standardized procedures (ATS recommendations), performed by specifically trained and certified personnel; a fully-computerized spirometer with customized software was used for spirometry. A reference center made monthly controls. Overall, 638 cases and 984 controls were examined. Spirometric measurements were obtained in 607 cases and 912 controls; 508 and 747 tests with at least three acceptable curves were obtained in cases and in controls, respectively (NS). The percentage of reproducible tests ranged between 95.8% for FEV₁ in controls and 87.6% for FVC in cases. The average reproducibility for FEV₁ was 61.6 ml in cases and 58.3 ml in controls (NS). Cognitive impairment, shorter 6-min walk distance, and lower educational level were found to be independent risk factors for a poorer acceptability rate (logistic regression analysis). Male sex and age were risk factors for a poorer reproducibility of FEV₁. Reproducibility tended to improve with time (p <0.001). Although spirometry becomes increasingly difficult in aging patients, a rigorous quality control program can ensure that reliable data are obtained in the majority of patients.