Construct validation of an automated 24-h bladder diary smartphone app

Introduction:

A universal mobile application (WeShare URO by Symptelligence Medical Informatics, LLC) was developed to allow patients to provide diary and symptom information to the provider prior to the visit and to aid in the tracking of treatment progress. The purpose of the present study is to validate that the app correctly calculates the values required for the proper evaluation of a patients’ symptoms.

Materials and Methods:

Data from paper diaries of men with lower urinary tract symptoms (LUTS) was entered into the app. Total urine volume (TUV), total voids, actual number of nightly voids (ANV), nocturnal urine volume (NUV), maximum voided volume (MVV), nocturia index (Ni), nocturnal polyuria index (NPi), predicted number of nightly voids (PNV), and nocturnal bladder capacity index (NBCi) were calculated. Correlations between manual (Manual and Quickhand) and automatic (App) values were calculated using Spearman’s nonparametric rank coefficient.

Results:

The study included 66 paper diaries completed by a total of 51 male patients (median age = 68, IQR = 6) evaluated for LUTS. After applying exclusion criteria, 35 diaries were left for analysis (median age = 68, IQR = 0). Manual calculations were similar to those calculated by the app (0% - 2% difference). Comparison between Quickhand and App calculations had a higher difference (0% – 27%).

Conclusions:

Bladder diary applications can improve LUTS care through accurate calculations via an automated scaling equation. The error rate of “Quickhand” (calculations done by a clinician as a back-of-the-envelope method) supports the claim that these calculations are inaccurate and that an automated scaling equation provides more specific values critical to therapeutic decision-making.