The cut-off values for Visual Analogue Scale (VAS) and for the Assessment Tool for Asthma (ATA) according the Control for Asthma and Allergic Rhinitis Test (CARAT)

Abstract

Aim: The Control Test for Asthma and Allergic Rhinitis (CARAT) composed of 10 questions is a validated tool to assess asthma and rhinitis control. The cut-off values for the Visual Analogue Scale (VAS) and for the Assessment Tool for Asthma (ATA) according CARAT were evaluated in the study for having practical cut-off points of the disease control in the outpatient clinics.

Method: Patients with asthma and allergic rhinitis were tested with the CARAT with ATA and with VAS for rhinitis and for asthma separately by specialist at the same day. Receiver Operating Characteristic (ROC) analysis is used to determine the cut-off values for VAS and for ATA according CARAT.

Results: Seventy-seven of the 100 patients were female (mean age 46.5 years). The means for CARAT, ATA and VAS asthma, VAS rhinitis scores were 19.6±7.2, 54.9±18.1, 4.1±3, 4.7±3.3 respectively. When the cut-off point of the VAS-rhinitis was taken as 7.5, the sensitivity was 99.9% and the specificity 93.9% and the area under the ROC curve (AUC) was 99.4. When the cut-off point of the ATA was taken as 55, the sensitivity was 87.9% and the specificity 92.9% and the area under the ROC curve (AUC) was 94.5.

Conclusion: Cut-off points 7.5 for VAS-rhinitis and 55 for ATA can be two different practical instruments in outpatient clinics for understanding the control of rhinitis and asthma with rhinitis beside CARAT.