Refinement and further application of the Qualities of Sore Throat Index (QuaSTI)

Abstract

Aim: The Qualities of Sore Throat Index (QuaSTI) assesses the status of patient-reported pharyngeal pain. One study used QuaSTI in isolation; a separate study used QuaSTI plus the Sore Throat Scale (STS). Both studies also used a Sore Throat Pain Intensity Scale (STPIS). This study evaluates STS and STPIS as instruments to refine the QuaSTI. Materials & methods: Correlational analysis determined the degree of association between STPIS and STS. Confirmatory factor analyses evaluated the proposed factor structure of QuaSTI. Results: A strong correlation between STS and STPIS (r = 0.91; p < 0.01), supports the use of STS in QuaSTI. Analyses confirm a three-factor structure for the 10-item QuaSTI and validate inclusion of an additional item to create an 11-item tool for measuring pharyngeal pain. Conclusion: The QuaSTI represents a robust and validated tool for measuring therapeutic effects in patients with pharyngitis.