Overcrowding Indicators in EDs Across Countries: Scoping Review

Overcrowding Indicators in EDs Across Countries: Scoping Review
Authors: Mohd Nasir NN, Indera Putera KAS, Noris NJ, Libasin Z, Krishnan M, Salaton NF, Lum KY, Renu Abdullah NN, Saimy IS
Journal: Interactive Journal of Medical Research, May 2026

Conclusions:

  • There’s still no global “standard dashboard” for ED crowding—studies use a wide mix of indicators, limiting benchmarking and policy comparisons.

  • Internationally, crowding measurement is dominated by throughput metrics, especially ED length of stay (LOS).

  • Input (demand) and output (exit block/bed access) measures are underused, despite many clinicians believing output factors drive the worst crowding.

  • Practical takeaway: if you’re building an ED crowding scorecard, LOS + LWBS + waiting time are the most common denominators internationally, but you’ll miss key system failure modes unless you also track output/boarding.\

Practice pearls (ops-minded EM takeaways):

  • If your leadership wants a “simple” crowding dashboard, this review supports starting with: ED LOS, waiting time, LWBS (common, comparable, easy to trend).

  • To make it clinically truthful, add at least one output/boarding metric (e.g., admit-to-bed time, # boarded >6–8h, ED boarding hours per day).

  • Research gap worth noting: we still need validated composite measures that capture the real-world complexity—especially where throughput looks okay but the ED is gridlocked due to exit block.

Results:

  • 117 studies included out of 1,347 screened.

  • 307 indicators extracted → consolidated into 26 distinct indicators.

  • Distribution of indicators by domain:

    • Throughput: 209/307 (68%)

    • Output: 62/307 (20%)

    • Input: 36/307 (12%)

  • Most frequently reported throughput indicators:

    • ED LOS: cited 87 times (top indicator)

    • LWBS: 30 times

    • Waiting time: 30 times

  • LOS repeatedly emerged as a primary marker of bottlenecks/operational inefficiency across systems.

Methods:

  • Scoping review (Oct–Nov 2023) across PubMed, Scopus, Emerald Insight, Google Scholar.

  • Multi-reviewer screening (9 reviewers for L1/L2; consensus resolution); one reviewer did full-text synthesis and descriptive analysis.

  • Indicators categorized into:

    • Input (demand/arrivals),

    • Throughput (ED processes: triage, diagnostics, treatment),

    • Output (exit block: bed shortages, transfer delays).

  • Indicators ranked by frequency of reporting across countries/settings.

Mohd Nasir NN, Indera Putera KAS, Noris NJ, Libasin Z, Krishnan M, Salaton NF, Lum KY, Abdullah NNR, Saimy IS. Overcrowding Indicators in Emergency Departments Across Countries: Scoping Review. Interact J Med Res. 2026 May 5;15:e78073. doi: 10.2196/78073. PMID: 42085686; PMCID: PMC13143202.

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