Objective: To assess the reliability, agreement with provider measurement, and patient preferences regarding patient self-measurement of postvoid residual bladder volume (PVR). PVR measurement in the nonhealthcare setting is a valuable opportunity for remote monitoring of voiding dysfunction patients. We hypothesized that patient self-measurement of PVR using a smart-device portable ultrasound system with artificial intelligence would demonstrate high reliability, strong agreement with provider measurement, and be preferred over provider measurements.
Methods: Patients were enrolled during outpatient Urology visits. PVRs were measured in triplicate by providers using each of the following: an FDA-cleared (standard) bladder scanner, the portable ultrasound probe using ultrasound images (Butterfly US image mode), and the portable ultrasound probe using abstract images (Butterfly abstract mode). Subjects self-measured PVRs in triplicate using both imaging modes and reported their experiences via questionnaire. Reliability was assessed via intraclass correlation. Agreement between methods was assessed via Bland-Altman analyses using a clinically acceptable difference threshold of 50 mL.
Results: Fifty patients were enrolled. Intraclass correlations ranged from 0.95 to 0.98 for each method. 95% limits of agreement between standard bladder scanner and patient self-measurement were - 71.73 mL and 86.73 mL using Butterfly US image mode and - 93.84 mL and 112.52 mL using Butterfly abstract mode, respectively. Most patients preferred self-measurement over provider measurement (74% vs 26%, respectively).
Conclusion: Patient self-measurement of PVR using smart-device integrated portable ultrasound probes is feasible, reliable, and preferred by patients. Limits of agreement between patient self-measurement and standard bladder scanner measurements exceeded our clinically acceptable difference threshold, though the inherent error of ultrasound-based bladder volume measurements should be considered. Longitudinal PVR assessments in nonhealthcare settings may facilitate remote monitoring of voiding dysfunction patients.
Published by Elsevier Inc.