Accuracy of prognostic scoring tools for ICU triage and mortality among patients in low- and middle-income countries: a systematic review and meta-analysis.

BACKGROUND

Early warning and severity scores are widely used to support triage and predict clinical deterioration. Their diagnostic performance in low- and middle-income countries (LMICs) however remains uncertain due to differences in patient populations and healthcare resources compared with high-income settings.

OBJECTIVES

This study aimed to evaluate and compare the diagnostic accuracy of commonly used scoring systems for predicting intensive care unit (ICU) admission and in-hospital mortality among adults presenting to emergency departments in LMICs.

METHODS

We conducted a systematic review and meta-analysis of PubMed, Science Direct, Web of Science and the Cochrane Library. Observational studies assessing the accuracy of early warning or severity scores for ICU admission or in-hospital mortality of patient admitted to the emergency department were included. Data were pooled using a bivariate random-effects model to estimate sensitivity, specificity and area under the curve (AUC). Study quality was appraised using QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies 2).

RESULTS

Twenty-six studies comprising over 45 000 patients from LMICs were analysed. For in-hospital mortality, quick Sequential Organ Failure Assessment (qSOFA) showed sensitivity of 0.61 and specificity of 0.73 (AUC=0.67); National Early Warning Score (NEWS)-family had higher sensitivity (0.80) but lower specificity (0.56, AUC=0.68); Modified Early Warning Score (MEWS) provided high specificity (0.83) but lower sensitivity (0.53, AUC=0.68). For ICU admission, NEWS demonstrated balanced performance (sensitivity 0.74, specificity 0.77, AUC=0.76), while Rapid Emergency Medicine Score (REMS) achieved the highest overall accuracy (sensitivity 0.79, specificity 0.85, AUC=0.81). Considerable heterogeneity was observed across studies.

CONCLUSIONS

Early warning scores show moderate accuracy in predicting ICU admission and in-hospital mortality in LMIC emergency departments. qSOFA and MEWS may be most useful when high specificity is required, while NEWS and REMS provide more balanced performance, with REMS showing the best overall accuracy. No single score was optimal across settings, underscoring the need for local validation and adaptation in resource-limited environments.