Closing the documentation gap: accuracy and completeness of a novel EHR-integrated gravitational urine production gauge vs. manual charting

Abstract

Manual urine output (UO) measurement is labour-intensive and prone to error. The Gravity of Flow study evaluated a fully reusable gravitational urine production gauge (UPG) designed for continuous UO monitoring and Electronic Health Record (EHR) integration.

This RCT enrolled 55 patients (50 analysed after 5 exclusions) to compare the UPG against standard manual charting. Performance was validated using a 24-hour gold-standard volume container. Primary outcomes included data completeness and volumetric accuracy.

The UPG demonstrated superior data completeness compared to manual charting (98.7% vs. 37.9%). Completeness remained high for the UPG across all shifts (98–100%), whereas manual charting dropped significantly during afternoon and night shifts (35%; 36%). Regarding accuracy, the UPG outperformed manual methods with a significantly lower Mean Absolute Error (93.6 mL vs. 276.8 mL; p < 0.05) and a Mean Absolute Percentage Error of 4.0% vs. 17.5%. The UPG showed excellent correlation (Pearson r = 0.997) and 88% of measurements fell within a ±10% error margin, compared to only 44% for manual charting.

The UPG provides highly accurate, continuous, and reliable UO data, significantly reducing the documentation gaps inherent to manual monitoring. By eliminating manual documentation gaps, the system enables automated clinical decision support, optimizing fluid management while reducing nursing workload.Figure 1