Abstract/Summary

Background and aims: Recurrent urinary tract infection (rUTI) has significant negative consequences for a wide variety of quality of life (QoL) domains. Without adequate validation and assessment of the unique insights of people living with rUTI, clinical results cannot be fully understood. The Recurrent UTI Impact Questionnaire (RUTIIQ), a novel patient-reported outcome measure of rUTI psychosocial impact, has been robustly developed with extensive patient and clinician input to facilitate enhanced rUTI management and research. This study aimed to confirm the structural validity of the RUTIIQ, assessing its strength and bifactor model fit. Methods: A sample of 389 adults experiencing rUTI (96.9% female, aged 18–87 years) completed an online cross-sectional survey comprising a demographic questionnaire and the RUTIIQ. A bifactor graded response model was fitted to the data, optimising the questionnaire structure based on item fit, discrimination capability, local dependence, and differential item functioning. Results: The final RUTIIQ demonstrated excellent bifactor model fit (RMSEA = .054, CFI = .99, SRMSR = .052), and mean-square fit indices indicated that all included items were productive for measurement (MNSQ = .52 – 1.41). The final questionnaire comprised an 18-item general ‘rUTI QoL impact’ factor, and five sub-factor domains measuring ‘personal wellbeing’ (3 items), ‘social wellbeing’ (4 items), ‘work and activity interference’ (4 items), ‘patient satisfaction’ (4 items), and ‘sexual wellbeing’ (3 items). Together, the general factor and five sub-factors explained 81.6% of the common model variance. All factor loadings were greater than .30 and communalities greater than .60, indicating good model fit and structural validity. Conclusions: The 18-item RUTIIQ is a robust, patient-tested questionnaire with excellent psychometric properties, which capably assesses the patient experience of rUTI-related impact to QoL and healthcare satisfaction. Facilitating standardised patient monitoring and improved shared decision-making, the RUTIIQ delivers the unique opportunity to improve patient-centred care.