Background: Evaluation of acute rhinosinusitis treatment effectiveness is based on patient-reported relief of symptoms. This study was designed to develop a multiattribute utility scoring algorithm for the Major Symptom Score (MSS) and secondarily to evaluate the psychometric characteristics (i.e., validity and responsiveness) of the MSS Utility Index (MSSUI).
Methods: Adult patients with acute rhinosinusitis were recruited for this longitudinal observational study through primary care and specialist physician offices. One hundred ninety patients participated in a preference elicitation exercise for MSS health states. Resulting preference data were used to generate a utility scoring algorithm for the MSS. Participants completed the MSS and 20-Question Sino-Nasal Outcome Test (SNOT-20) at baseline and completed the MSS twice daily for 15 days via daily diary. On days 7 and 15, participants completed the MSS, SNOT-20, and Overall Treatment Effect scale and were evaluated by physicians via the Physician Global Improvement Scale (PGIS).
Results: At baseline, the mean ± SD. MSSUI score was 0.51 ± 0.17 and was negatively correlated with SNOT-20 scores (r = -0.58; p < 0.001). Days 2-8 average MSSUI scores were negatively correlated with day 7 SNOT-20 (r = -0.46; p < 0.001) and PGIS (r = -0.22; p < 0.001) scores; whereas days 9-15 average MSSUI scores were inversely related to day 15 SNOT-20 (r = -0.40; p < 0.001) and PGIS (r = -0.32, p < 0.001) scores. Mean MSSUI scores improved from baseline with effect sizes at days 7 and 15 of 0.82 and 1.20, respectively.
Conclusion: The MSSUI represents an acceptable and psychometrically sound patient-reported end point for clinical trials comparing treatments for acute rhinosinusitis.