Performance of scoring systems in selecting short stay medical admissions suitable for assessment in same day emergency care: an analysis of diagnostic accuracy in a UK hospital setting

Objectives: To assess the performance of the Amb score and Glasgow Admission Prediction Score (GAPS) in identifying acute medical admissions suitable for same day emergency care (SDEC) in a large urban secondary centre.

Design: Retrospective assessment of routinely collected data from electronic healthcare records.

Setting: Single large urban tertiary care centre.

Participants: All unplanned admissions to general medicine on Monday-Friday, episodes starting 08:00-16:59 hours and lasting up to 48 hours, between 1 April 2019 and 9 March 2020.

Main outcome measures: Sensitivity, specificity, positive and negative predictive value of the Amb score and GAPS in identifying patients discharged within 12 hours of arrival.

Results: 7365 episodes were assessed. 94.6% of episodes had an Amb score suggesting suitability for SDEC. The positive predictive value of the Amb score in identifying those discharged within 12 hours was 54.5% (95% CI 53.3% to 55.8%). The area under the receiver operating characteristic curve (AUROC) for the Amb score was 0.612 (95% CI 0.599 to 0.625).42.4% of episodes had a GAPS suggesting suitability for SDEC. The positive predictive value of the GAPS in identifying those discharged within 12 hours was 50.5% (95% CI 48.4% to 52.7%). The AUROC for the GAPS was 0.606 (95% CI 0.590 to 0.622).41.4% of the population had both an Amb and GAPS score suggestive of suitability for SDEC and 5.7% of the population had both and Amb and GAPS score suggestive of a lack of suitability for SDEC.

Conclusions: The Amb score and GAPS had poor discriminatory ability to identify acute medical admissions suitable for discharge within 12 hours, limiting their utility in selecting patients for assessment within SDEC services within this diverse patient population.