Calc Function

    • Calcs that help predict probability of a diseaseDiagnosis
    • Subcategory of 'Diagnosis' designed to be very sensitiveRule Out
    • Disease is diagnosed: prognosticate to guide treatmentPrognosis
    • Numerical inputs and outputsFormula
    • Med treatment and moreTreatment
    • Suggested protocolsAlgorithm





    Chief Complaint


    Organ System


    Patent Pending

    Modified Early Warning Score (MEWS) for Clinical Deterioration

    Determines the degree of illness of a patient.


    Different institutions and regions may use different modifications of the MEWS. Verify that your institution uses the same points assignments listed here.

    When to Use
    Why Use

    The MEWS can be used on all hospitalized patients to allow for the early detection of clinical deterioration and potential need for higher level of care.

    • The Modified Early Warning System (MEWS) is a tool designed to identify patients with declining conditions.
    • It has been shown to be superior to clinical judgement for this purpose.
    • It was originally designed for nurses but can be used by any healthcare professional with adequate training.
    • MEWS is based on the principle that clinical deterioration can be seen through subtle changes in a number of parameters as well as large changes within a single variable.
    • The scale is calibrated to different populations and sometimes expanded to include additional parameters.
    • While a score of 5 or more has been shown to be associated with a higher likelihood of admission to an intensive care unit or death, this threshold can be modified to accommodate different patient populations or clinical settings.
    • The National Early Warning Score (NEWS) 2 was developed and updated by the Royal College of Physicians in the UK to standardize the identification and response to deteriorating patients.
    • Patients with low MEWS can continue receiving their usual care and observation.
    • Patients with high MEWS should be watched more attentively and considered for transfer to a higher care unit such as an ICU.
    ≤70 mmHg
    71-80 mmHg
    81-100 mmHg
    101-199 mmHg
    ≥200 mmHg
    <40 bpm
    41-50 bpm
    51-100 bpm
    101-110 bpm
    111-129 bpm
    ≥130 bpm
    <9 bpm
    9-14 bpm
    15-20 bpm
    21-29 bpm
    ≥30 bpm
    <35°C / 95°F
    35–38.4°C / 95–101.1°F
    ≥38.5°C / 101.3°F
    Reacts to voice
    Reacts to pain


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    Next Steps
    Creator Insights


    Once the MEWS identifies a patient at risk of deterioration, the medical team will need to identify the cause and address it accordingly.

    Critical Actions

    • This score can be used by any healthcare worker with proper training in how to use it and interpret the results.
    • It is meant to be used on a regular basis rather than once on admission.


    Addition of the selected points; points assigned below:

    Facts & Figures

    See formula table; below:

    Criteria Point Value
    Systolic BP (mmHg)
    ≤70 +3
    71-80 +2
    81-100 +1
    101-199 0
    ≥200 +2
    Heart rate (beats per minute)
    <40 +2
    41-50 +1
    51-100 0
    101-110 +1
    11-129 +2
    >130 +3
    Respiratory rate (breaths per minute)
    <9 +2
    9-14 0
    15-20 +1
    21-29 +2
    >30 +3
    Temperature in °C (°F)
    <35 (<95) +2
    35.0–38.4 (95–101.12) 0
    >38.5 (101.3) +2
    Alert? 0
    Voice? +1
    Pain? +2
    Unresponsive? +3


    • A score ≥5 is statistically linked to increased likelihood of death or admission to an intensive care unit.
    • For any single physiological parameter scored +3, consider higher level of care for patient.

    Evidence Appraisal

    • The early warning score (EWS) was initially described in the Morgan study (listed below).
    • The Modified Early Warning Score (MEWS) was prospectively validated in 709 patients. Complete data was available for 673 patients. A score of 5 or more on the MEWS scale was shown to be associated with an increased risk of clinical deterioration and death.
    • In order to validate MEWS in a population of surgical patients, Gardner-Thorpe et al prospectively studied 334 consecutive ward patients. In this study, a MEWS of 4 or more was found to be 75% sensitive and 83% specific for the need to transfer a patient to a critical care unit. A MEWS of 5 or more was less sensitive (38%) but more specific (89%).
    Dr. Christian Peter Subbe

    About the Creator

    Christian Peter Subbe, MD, MRCP (London), is a practicing clinician in Respiratory, General Internal & Intensive Care Medicine. He is a senior clinical lecturer at Bangor University and a consultant at the Ysbyty Gwynedd, Bangor. Dr. Subbe's current research interests include recognition of acute illness, the interface of acute and critical care medicine, rapid response systems and smoking cessation in hospitalized patients.

    To view Dr. Christian Peter Subbe's publications, visit PubMed

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    About the Creator
    Dr. Christian Peter Subbe
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