Journal of Patient-Reported Outcomes (Mar 2025)

Development and psychometric evaluation of a patient-reported symptom index for patients with non-muscle invasive bladder cancer: the NMIBC-SI

  • Claudia Rutherford,
  • Margaret-Ann Tait,
  • Daniel S. J. Costa,
  • Madeleine T. King,
  • David P. Smith,
  • Shomik Sengupta,
  • Joseph Ischia,
  • Andrew Mitterdorfer,
  • Dickon Hayne,
  • Roger Watson,
  • Paul Anderson,
  • Mark Frydenberg,
  • Peter Gilling,
  • Nicholas Buchan,
  • Euan Green,
  • Noel Clarke,
  • Stephen A. Boorjian,
  • Badrinath Konety,
  • Jeffrey M. Holzbeierlein,
  • Peter C. Black,
  • Venu Chalasani,
  • Jörg Henseler,
  • Manish I. Patel,
  • on behalf of the NMIBC-SI Study Group

DOI
https://doi.org/10.1186/s41687-025-00864-7
Journal volume & issue
Vol. 9, no. 1
pp. 1 – 13

Abstract

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Abstract Background and objective Non-muscle invasive bladder cancer (NMIBC) is a chronic condition requiring frequent follow-up with endoscopic examinations, tumour resections and intravesical treatments. In this clinical context, patient-reported outcomes (PROs) have enormous potential to inform treatment assessment and recommendations for NMIBC. We aimed to develop and evaluate a patient-reported NMIBC Symptom Index (NMIBC-SI) to facilitate clinical research and enhance care. Methods NMIBC-SI items were developed based on existing literature and qualitative interviews with patients and clinicians, and evaluated in two field tests: item reduction, using NMIBC-SI data from 220 patients on active treatment from nine Australian centres; reliability and validity evaluation of item-reduced version using NMIBC-SI data from 232 patients from five countries. Results NMIBC-SI assesses disease and treatment-related symptom burden and two treatment-specific side-effects (cystoscopy, intravesical BCG/Chemotherapy). Composite analysis supported a single composite model including core symptom and cystoscopy index items (Intravesical index items were not tested due to small sample). Test-retest reliability was strong (range 0.894–0.91). As expected, the NMIBC-SI was able to discriminate between no treatment and any treatment groups, and no treatment and chemo/BCG groups, providing evidence towards validity. Conclusions and clinical implications NMIBC-SI assesses patients’ self-reported symptom burden and can be used to evaluate NMIBC treatments from the perspective of patients. The NMIBC-SI is acceptable to patients and has evidence for reliability and validity. Future validation work with patients with greater symptom burden is warranted.

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