Accuracy of a Smart Diaper System for Nursing Home Residents for Automatically Detecting Voided Volume: Instrument Validation Study

Abstract

BackgroundDiapers are commonly used by older patients with urination disorders. A smart diaper system (SDS) may be able to estimate the weight of urine comparably to conventional measurements made by weighing diapers. ObjectiveThe aim of the current research is to determine the degree of accuracy of an SDS technology specifically designed for the management of urination routines and the use of incontinence pads in older adults. MethodsFrom January to December 2022, 97 older patients with at least 1 chronic disease from 3 nursing homes were included. In this study, the SDS was used for 1 month per patient after obtaining their consent; all patients originally used traditional diapers in the nursing home. The index test measured the change in electrical resistance of the SDS and the reference test measured the change in actual urine weight. When measuring the actual urine weight, the degree of absorption was directly confirmed with the naked eye because the expression value varied according to pressure changes caused by the user’s movement or position. The Pearson correlation was used to determine the correlation between the 2 test methods, the intraclass correlation coefficient (ICC) was used to check the degree of agreement between the evaluators, and the Bland-Altman test was used to confirm whether there was a significant difference between the 2 test methods. ResultsThe average age of the 97 participants was 86.48 (SD 6.26) years, with 10 men and 87 women. There were 73 patients (75%) with hypertension, 86 patients (88%) with dementia, and 86 patients (88%) with 2 or more comorbidities, accounting for the majority. The Pearson correlation coefficient and ICC were 0.971 and 0.985 (P<.001). In the Bland-Altman figure, the difference in the mean between the 2 tests was evenly scattered without showing a specific pattern, indicating that the SDS and actual urine weight were very consistent. The difference between the mean of the 2 tests was –0.045 of the standardized mean difference, and all measurements were located within the 95% CI, so this confirms that the 2 test methods are equivalent. ConclusionsOur study showed a fairly high correlation coefficient and ICC for all patient groups, which reveals that the 2 tests were very consistent and that the SDS can replace traditional diapers, even in a real clinical setting. This study shows the possibility that heath care professionals could be alerted by the SDS to the need for pad replacement due to incontinence, thus avoiding the development of dermatological complications.