Differential behaviour of a risk score for emergency hospital admission by demographics in Scotland-A retrospective study

PLOS Digit Health. 2024 Dec 17;3(12):e0000675. doi: 10.1371/journal.pdig.0000675. eCollection 2024 Dec.

Abstract

The Scottish Patients at Risk of Re-Admission and Admission (SPARRA) score predicts individual risk of emergency hospital admission for approximately 80% of the Scottish population. It was developed using routinely collected electronic health records, and is used by primary care practitioners to inform anticipatory care, particularly for individuals with high healthcare needs. We comprehensively assess the SPARRA score across population subgroups defined by age, sex, ethnicity, socioeconomic deprivation, and geographic location. For these subgroups, we consider differences in overall performance, score distribution, and false positive and negative rates, using causal methods to identify effects mediated through age, sex, and deprivation. We show that the score is well-calibrated across subgroups, but that rates of false positives and negatives vary widely, mediated by various causes including variability in demographic characteristics, admission reasons, and potentially differential data availability. Our work assists practitioners in the application and interpretation of the SPARRA score in population subgroups.

Grants and funding

This study was supported by The Alan Turing Institute, PHS, the MRC Human Genetics Unit at the University of Edinburgh, Durham University and Health Data Research UK. This project is supported by the Health Foundation, an independent charity committed to bringing about better health and health care for people in the UK. IT, JL, CAV, LJMA were supported by the Wave 1 of The UKRI Strategic Priorities Fund under the EPSRC Grant EP/T001569/1 and EPSRC Grant EP/W006022/1, particularly the “Health and Medical Sciences” theme within those grants and The Alan Turing Institute. IT, JL, CAV, LJMA were also supported by Health Data Research UK, an initiative funded by UKRI, the Department of Health and Social Care (England), the devolved administrations, and leading medical charities. LJMA was partially supported by a Health Programme Fellowship at The Alan Turing Institute. The funders had no role in the study design, data collection, analysis, decision to publish, or preparation of the manuscript.