ABSTRACT
Objectives: To confirm the structural validity of the Recurrent Urinary Tract Infection Symptom Scale (RUTISS), determining whether a bifactor model appropriately fits the questionnaire's structure and identifying areas for refinement. Used in conjunction with established clinical testing methods, this patient-reported outcome measure addresses the urgent need to validate the patient perspective. Patients and methods: A clinically and demographically diverse sample of 389 people experiencing recurrent UTI across 37 countries (96.9% female biological sex, aged 18-87 years) completed the RUTISS online. A bifactor graded response model was fitted to the data, identifying potential items for deletion if they indicated significant differential item functioning (DIF) based on sociodemographic characteristics, contributed to local item dependence or demonstrated poor fit or discrimination capability. Results: The final RUTISS comprised a 3-item symptom frequency section, a 1-item global rating of change scale and an 11-item general 'rUTI symptom and pain severity' subscale with four sub-factor domains measuring 'urinary symptoms', 'urinary presentation', 'UTI pain and discomfort' and 'bodily sensations'. The bifactor model fit indices were excellent (root mean square error of approximation [RMSEA] = 0.041, comparative fit index [CFI] = 0.995, standardised root mean square residual [SRMSR] = 0.047), and the mean-square fit statistics indicated that all items were productive for measurement (mean square fit indices [MNSQ] = 0.64 - 1.29). Eighty-one per cent of the common model variance was accounted for by the general factor and sub-factors collectively, and all factor loadings were greater than 0.30 and communalities greater than 0.60. Items indicated high discrimination capability (slope parameters > 1.35). Conclusion: The 15-item RUTISS is a patient-generated, psychometrically robust questionnaire that dynamically assesses the patient experience of recurrent UTI symptoms and pain. This brief tool offers the unique opportunity to enhance patient-centred care by supporting shared decision-making and patient monitoring.
ABSTRACT
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, optimizing 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 = 0.054, CFI = 0.99, SRMSR = 0.052), and mean-square fit indices indicated that all included items were productive for measurement (MNSQ = 0.52-1.41). The final questionnaire comprised an 18-item general "rUTI QoL impact" factor, and five subfactor domains measuring "personal wellbeing" (three items), "social wellbeing" (four items), "work and activity interference" (four items), "patient satisfaction" (four items), and "sexual wellbeing" (three items). Together, the general factor and five subfactors explained 81.6% of the common model variance. All factor loadings were greater than 0.30 and communalities greater than 0.60, 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 standardized patient monitoring and improved shared decision-making, the RUTIIQ delivers the unique opportunity to improve patient-centered care.
Subject(s)
Quality of Life , Urinary Tract Infections , Adult , Humans , Female , Male , Quality of Life/psychology , Cross-Sectional Studies , Surveys and Questionnaires , Patient Reported Outcome Measures , Psychometrics/methods , Reproducibility of ResultsABSTRACT
Objectives: This study aimed to develop and validate a tailored patient-reported outcome measure (PROM) evaluating the patient experience of recurrent urinary tract infection (rUTI) symptom severity. This measure was designed to supplement clinical testing methods, allowing full assessment of the patient experience of rUTI symptom burden, while enhancing patient-centred UTI management and monitoring. Subjects and Methods: The Recurrent Urinary Tract Infection Symptom Scale (RUTISS) was developed and validated using a three-stage methodology, in accordance with gold-standard recommendations. Firstly, a two-round Delphi study was conducted to gain insights from 15 international expert clinicians working in rUTI, developing an initial pool of novel questionnaire items, assessing content validity and making item refinements. Next, two phases of one-to-one semi-structured cognitive interviews were conducted with a diverse sample of 28 people experiencing rUTI to assess questionnaire comprehensiveness and comprehensibility, making refinements after each phase. Finally, a comprehensive pilot of the RUTISS was conducted with 240 people experiencing rUTI across 24 countries, providing data for psychometric testing and item reduction. Results: Exploratory factor analysis indicated a four-factor structure comprising: 'urinary pain and discomfort', 'urinary urgency', 'bodily sensations' and 'urinary presentation', together accounting for 75.4% of the total variance in data. Qualitative feedback from expert clinicians and patients indicated strong content validity for items, which was supported by high content validity indices in the Delphi study (I-CVI > 0.75). Internal consistency and test-retest reliability of the RUTISS subscales were excellent (Cronbach's α = 0.87-0.94 and ICC = 0.73-0.82, respectively), and construct validity was strong (Spearman's ρ = 0.60-0.82). Conclusion: The RUTISS is a 28-item questionnaire with excellent reliability and validity, which dynamically assesses patient-reported rUTI symptoms and pain. This new PROM offers a unique opportunity to critically inform and strategically enhance the quality of rUTI management, patient-clinician interactions, and shared-decision making by monitoring key patient-reported outcomes.
ABSTRACT
PURPOSE: Recurrent urinary tract infection (rUTI) is a highly prevalent condition associated with significant poor quality of life outcomes. A patient-reported outcome measure (PROM) of rUTI-associated psychosocial impact is urgently required to supplement clinical evaluation and validate the challenges experienced by patients. This study therefore developed and validated the Recurrent UTI Impact Questionnaire (RUTIIQ). METHODS: A rigorous four-stage methodology was followed: (I) concept elicitation through a qualitative survey of the experiences of people with rUTI (N = 1983); (II) Delphi expert screening of the RUTIIQ with expert rUTI clinicians (N = 15); (III) one-to-one cognitive interviews with people experiencing rUTI (N = 28) to evaluate the comprehensiveness and comprehensibility of the RUTIIQ, and (IV) full pilot testing of the RUTIIQ with people experiencing rUTI (N = 240) to perform final item reduction and psychometric analysis. RESULTS: Exploratory factor analysis demonstrated a five-factor structure comprising: 'patient satisfaction', 'work and activity interference', 'social wellbeing', 'personal wellbeing', and 'sexual wellbeing', collectively accounting for 73.8% of the total variance in pilot scores. Results from expert clinicians and patients indicated strong item content validity (I-CVI > .75). The internal consistency and test-retest reliability of the RUTIIQ subscales were excellent (Cronbach's α = .81-.96, ICC = .66-.91), and construct validity was strong (Spearman's ρ > .69). CONCLUSION: The RUTIIQ is a 30-item questionnaire with excellent psychometric properties, assessing the patient-reported psychosocial impact of living with rUTI symptoms and pain. This new instrument delivers the unique opportunity to enhance patient-centred care through standardised observation and monitoring of rUTI patient outcomes. TRIAL REGISTRATION: This study was pre-registered with ClinicalTrials.gov (identifier: NCT05086900).
