Measuring outcomes in allergic rhinitis: psychometric characteristics of a Spanish version of the congestion quantifier seven-item test (CQ7)

BACKGROUND: No control tools for nasal congestion (NC) are currently available in Spanish. This study aimed to adapt and validate the Congestion Quantifier Seven Item Test (CQ7) for Spain. METHODS: CQ7 was adapted from English following international guidelines. The instrument was validated in an observational, prospective study in allergic rhinitis patients with NC (N = 166) and a control group without NC (N = 35). Participants completed the CQ7, MOS sleep questionnaire, and a measure of psychological well-being (PGWBI). Clinical data included NC severity rating, acoustic rhinometry, and total symptom score (TSS). Internal consistency was assessed using Cronbach's alpha and test-retest reliability using the intraclass correlation coefficient (ICC). Construct validity was tested by examining correlations with other outcome measures and ability to discriminate between groups classified by NC severity. Sensitivity and specificity were assessed using Area under the Receiver Operating Curve (AUC) and responsiveness over time using effect sizes (ES). RESULTS: Cronbach's alpha for the CQ7 was 0.92, and the ICC was 0.81, indicating good reliability. CQ7 correlated most strongly with the TSS (r = 0.60, p < 0.01), the PGWBI general health dimension (r = 0.56, p < 0.01), and the MOS Sleep scale 'sleep short of breath' dimension (r = 0.49, p < 0.01). Correlations with acoustic rhinometry were generally low. The instrument discriminated well between NC severity groups (ES 0.33-2.07) and AUC was 0.93, indicating excellent sensitivity and specificity. The measure was responsive to change (ES = 1.1) in patients reporting improvement in NC. CONCLUSIONS: The Spanish version of the CQ7 is appropriate for detecting, measuring, and monitoring NC in allergic rhinitis patients.