The Congestion Quantifier Five-Item Test for Nasal Congestion: Refinement of the Congestion Quantifier Seven-Item Test

Abstract

Background Patients report that nasal congestion is the most bothersome symptom of allergic rhinitis (AR). Recently, a short, patient-reported congestion screener questionnaire, the Congestion Quantifier Seven-Item Test (CQ7), was developed to identify a level of congestion that may warrant patients seeking evaluation and possible treatment. We explored further item reduction of the CQ7 and examined the psychometric properties of this reduced set of items in a 15-day study of patients with confirmed AR or self-identified and clinician-confirmed congestion. Methods The CQ7 was subjected to item reduction methods and the psychometric properties of the reduced set of items were assessed. Results Two items were dropped—sinus pressure/pain and impact on work/school—because of lower item-rest correlations. The resulting Congestion Quantifier Five-Item screener (CQ5) performed comparably with the CQ7. Internal consistency reliability of both instruments were identical (alpha = 0.93); test–retest reliability from baseline to day 15 was similar (CQ7, alpha = 0.85; CQ5, alpha = 0.79). Both instruments were comparable in discriminating patients and controls (CQ7, area under the curve [AUC] = 0.97; CQ5, AUC = 0.96). A CQ5 score of 6 provided optimum balance of sensitivity (89.4%), specificity (88.6%), and correct classification (89%) for detecting congestion. Conclusions The CQ5, a patient-reported outcome screener, is slightly shorter but equally reliable, valid, and responsive as the CQ7 for evaluating differences in levels of severity of nasal congestion. It may have wider applicability than the CQ7 because of exclusion of the work/school impact item.