Development and validation of a new health-related quality of life instrument for patients with sinusitis

Background and Objective: There are few validated measures of sinusitis-specific health-related quality of life (HRQL). This study used patient focus and pretesting groups followed by a prospective cohort study to develop and validate a HRQL instrument for patients with sinusitis. Methods: Instrument development involved a systematic literature review, use of expert input, and patient focus and pretesting groups. Patients were recruited from the practices of primary care providers and otolaryngologists. The derived survey instrument then underwent prospective testing in patients with acute sinusitis, chronic sinusitis, allergic rhinitis, and asymptomatic controls. Reduced item scales of the original instrument were developed for symptom frequency and bothersomeness. The psychometric properties of the survey instrument were evaluated for reliability, construct validity, responsiveness, and interpretability. Results: In the prospective study, 47 patients with acute sinusitis and 50 patients with chronic sinusitis were compared to 18 patients with allergic rhinitis and 60 patients without nasal symptoms. Forty-three (91.5) patients with acute sinusitis completed the questionnaire at baseline and at 1-month follow-up. Internal consistency was high for the symptom impact scale for acute and chronic sinusitis patients. The symptom frequency and especially bothersomeness scales had lower internal consistency particularly for acute sinusitis patients. Reproducibility among surgical patients retested prior to their procedure was good for each scale. A high degree of disciminant validity was demonstrated when comparing sinusitis patients to other groups, and a high degree of convergent validity was seen when the new measures were compared to other HRQL measures at baseline. Among patients with acute sinusitis, the responsiveness and interpretability of the symptom frequency, bothersomeness and impact scales were excellent. Conclusions: This study developed and validated a new sinusitis-specific HRQL instrument. The instrument included symptom frequency, bothersomeness and impact scales. It was shown to be valid in patients with acute and chronic sinusitis, and highly responsive and interpretable in acute sinusitis patients managed in the primary care setting.