Discrimination analysis of spirometric measurements in asthma patients

Mohamed Faisal Lutfi, Mohamed Yusif Sukkar


Background: spirometric measurements are not equally effective in assessing ventilatory function of the lung. If one spirometric index is markedly abnormal, the entire flow-volume curve is likely to be affected, but
concordance of the parameters examined is not necessarily complete. This study aims to develop an effective spirometric score that gives the maximum ratio of difference between asthmatics and non-asthmatics to avoid
the problem of disconcordance of spirometric indices.
Patients and Methods:The study involved two groups: a control group of 56 apparently healthy subjects matched for gender and age with the study group of 100 patients with a medical history of asthma.
Discrimination analysis was used to condense 14 spirometric measurements into one representative score (DAS). The effectiveness of DAS on asthma diagnosis was tested with conditional ratios and Receiver
Operating Characteristic curve (ROC) curves.

Results:The area under ROC curve of DAS (0.93) is the highest compared with ROC curve of all other spirometric indices studied with higher statistical significance (P = 2.77E-19) and 95% confidence interval
(0.90 - 0.97). DAS when compared with FEV1%, has proved to be more sensitive (81% Vs 71%) specific (94.1% Vs 92.9%).
Conclusion:DAS is more sensitive, specific and accurate compared with other spirometric measurements, but like other indicators, it fails to reach 100% sensitivity and specifity on asthma diagnosis. DAS can be used
as a component of a multidimensional scoring system that also considers the symptoms and management intensity.
*Corresponding author: Department of Physiology, AlNeelain University

Full Text:



  • There are currently no refbacks.

ISSN: 1858-5345