Date Published: February 23, 2018
Publisher: Public Library of Science
Author(s): Cristina Ramos Hernández, Marta Núñez Fernández, Abel Pallares Sanmartín, Cecilia Mouronte Roibas, Luz Cerdeira Domínguez, Maria Isabel Botana Rial, Nagore Blanco Cid, Alberto Fernández Villar, Christophe Leroyer.
The Air-Smart Spirometer is the first portable device accepted by the European Community (EC) that performs spirometric measurements by a turbine mechanism and displays the results on a smartphone or a tablet.
In this multicenter, descriptive and cross-sectional prospective study carried out in 2 hospital centers, we compare FEV1, FVC, FEV1/FVC ratio measured with the Air Smart-Spirometer device and a conventional spirometer, and analyze the ability of this new portable device to detect obstructions. Patients were included for 2 consecutive months. We calculate sensitivity, specificity, positive and negative predictive value (PPV and NPV) and likelihood ratio (LR +, LR-) as well as the Kappa Index to evaluate the concordance between the two devices for the detection of obstruction. The agreement and relation between the values of FEV1 and FVC in absolute value and the FEV1/FVC ratio measured by both devices were analyzed by calculating the intraclass correlation coefficient (ICC) and the Pearson correlation coefficient (r) respectively.
200 patients (100 from each center) were included with a mean age of 57 (± 14) years, 110 were men (55%). Obstruction was detected by conventional spirometry in 73 patients (40.1%). Using a FEV1/FVC ratio smaller than 0.7 to detect obstruction with the Air Smart-Spirometer, the kappa index was 0.88, sensitivity (90.4%), specificity (97.2%), PPV (95.7%), NPV (93.7%), positive likelihood ratio (32.29), and negative likelihood ratio (0.10). The ICC and r between FEV1, FVC, and FEV1 / FVC ratio measured by the Air Smart Spirometer and the conventional spirometer were all higher than 0.94.
The Air-Smart Spirometer is a simple and very precise instrument for detecting obstructive airway diseases. It is easy to use, which could make it especially useful non-specialized care and in other areas.
The characteristics of portable devices including low cost, are simplicity of use, and reliability of results. Then they open new possibilities to optimize the diagnosis and monitoring of respiratory diseases. Obstructive airway disorders are of particular interest, because despite a prevalence of 5–10% in the general population, the rate of under-diagnosis reaches 80% [1,2].
A total of 200 patients (100 patients from each participating center) were consecutively enrolled in the study from the pulmonary function laboratories of the Hospital Álvaro Cunqueiro (Vigo) and the Pontevedra Hospital Complex. Of these, 110 (55%) were males. The mean age was 57 (± 14) years.
Spirometry is an essential technique for the early diagnosis, assessment of severity, and follow-up of chronic respiratory diseases, especially those with airflow obstruction, and should be considered as a basic exploration of pulmonary function. However, although spirometry is a diagnostic technique defined as simple, noninvasive, reliable, and safe, numerous studies show the existence of problems of underuse and variability in the quality of spirometry performed [11,12]. These factors likely contribute to the underdiagnosis of chronic respiratory diseases [1,2]. In the same line of work it is necessary to implement the use of quality spirometries. To this end, training and qualification programs should be developed for the professionals responsible for carrying out spirometry. Quality and easy-to-use spirometers should be also provided [3,13].