Modified Rankin Scale (mRS) for Stroke
The Modified Rankin Scale (mRS) is the most widely used outcome measure for stroke clinical trials and clinical practice, measuring the degree of disability in daily activities.
About
The mRS is a 7-level scale (0-6) that measures functional independence after stroke. Grade 0 = no symptoms, Grade 5 = severe disability (bedridden), Grade 6 = death. It is the primary endpoint in most acute stroke trials and is recommended by the AHA/ASA for standardized outcome assessment.
Formula
mRS = 0 (no symptoms) to 6 (death)
The Modified Rankin Scale is a single-question assessment: the clinician selects the grade that best describes the patient's level of functional independence over the past 24 hours. Grade 0: no symptoms at all. Grade 1: no significant disability despite minor symptoms — able to carry out all usual activities. Grade 2: slight disability — unable to carry out all previous activities but able to look after own affairs without assistance. Grade 3: moderate disability — requires some help but able to walk unassisted. Grade 4: moderately severe disability — unable to walk without assistance and unable to attend to own bodily needs without assistance. Grade 5: severe disability — bedridden, incontinent, requires constant nursing care and attention. Grade 6: dead. The assessment should be performed using a structured interview or questionnaire for optimal inter-rater reliability. Standard assessment timepoints in clinical trials are at discharge, 90 days, and 1 year post-stroke. The mRS is best assessed by a trained clinician familiar with stroke outcomes.
Score Interpretation
The Modified Rankin Scale (mRS) is the most widely used functional outcome measure in stroke research and clinical practice. It was originally described by Rankin in 1957 as a 5-level scale and was modified by van Swieten et al. in 1988 to the current 7-level version (0-6). The mRS is the recommended primary endpoint for stroke clinical trials by the American Heart Association/American Stroke Association (AHA/ASA) and the European Stroke Organisation (ESO). A score of 0-1 is typically considered an excellent outcome, 0-2 a favorable outcome, and 3-6 a poor outcome in clinical trials. The mRS has good inter-rater reliability (weighted κ = 0.78-0.93) when assessed through structured interviews. However, it has limitations including a ceiling effect for mild strokes and potential variability in scoring despite structured interview protocols. The mRS-9 (extended version adding 0.5 increments) has been proposed to improve sensitivity to change. The simplified modified Rankin Scale questionnaire (smRSq) is a validated telephone-administered alternative for follow-up assessments.
No Symptoms — 0–0
No residual symptoms from stroke.
Management: Excellent outcome. No specific intervention needed beyond standard secondary prevention.
No Significant Disability — 1–1
Able to carry out all usual activities despite minor symptoms.
Management: Good outcome. Outpatient follow-up and secondary prevention.
Slight Disability — 2–2
Unable to carry out all previous activities but able to look after own affairs without assistance.
Management: Mild disability. Consider outpatient rehabilitation and secondary prevention.
Moderate Disability — 3–3
Requires some help but able to walk unassisted.
Management: Moderate disability. Arrange home care services or outpatient rehabilitation.
Moderately Severe Disability — 4–4
Unable to walk without assistance and unable to attend to own bodily needs without assistance.
Management: Moderately severe disability. Consider skilled nursing facility or intensive home care.
Severe Disability — 5–5
Bedridden, incontinent, requires constant nursing care and attention.
Management: Severe disability. Requires constant nursing care, palliative care consultation, and family support.
Dead — 6–6
Deceased.
Management: Recorded for clinical trial endpoint or audit purposes.
Reference Ranges
| Population | Normal Range | Notes |
|---|---|---|
| Acute stroke patients (all types) | 0 — 6 points | Higher scores indicate greater disability. Grade 0 = no symptoms, Grade 6 = death. |
Dr. Mahmoud El-Sayed
Dr. Mahmoud El-Sayed is a board-certified neurologist and Fellow of the American Heart Association with expertise in cerebrovascular disease and stroke clinical trials.
View medical review board & editorial policy →Example Calculation
A 72-year-old female presents to the emergency department 2 hours after sudden onset of left-sided weakness and facial droop. She has a history of hypertension and atrial fibrillation (not on anticoagulation). NIHSS on admission is 14. CT head shows no hemorrhage. CT angiography reveals a right middle cerebral artery M1 occlusion. She receives IV alteplase and mechanical thrombectomy is successful with TICI 2b reperfusion at 4 hours from onset. At 24 hours, her NIHSS improves to 6. At 7 days, she has some residual left arm weakness but can walk independently, dress herself with minimal assistance, and manage her own toilet needs. She requires help with heavy housework and shopping. Modified Rankin Scale: Grade 2 (Slight disability — unable to carry out all previous activities but able to look after own affairs). This represents a favorable outcome (mRS 0-2) for her initial stroke severity. She is discharged home with outpatient occupational and physical therapy.
Related Conditions
Related Medications
Common Mistakes
Confusing mRS with NIHSS (NIH Stroke Scale)
NIHSS measures neurological deficit severity (acute assessment), while mRS measures functional disability/outcome (typically assessed at discharge, 90 days, or longer follow-up). They measure different constructs.
Assessing mRS too early after stroke
The mRS is designed as an outcome measure, not an acute assessment tool. Standard assessment timepoints are at discharge, 90 days, and 1 year post-stroke. Early assessment (within 24-48 hours) may not reflect final functional outcome.
Frequently Asked Questions
What is the difference between mRS and NIHSS?
Can mRS be assessed remotely?
References
- Rankin J. Cerebral vascular accidents in patients over the age of 60. II. Prognosis. Scott Med J. 1957;2(5):200-215. PubMed
- van Swieten JC, Koudstaal PJ, Visser MC, Schouten HJ, van Gijn J. Interobserver agreement for the assessment of handicap in stroke patients. Stroke. 1988;19(5):604-607. PubMed
- Banks JL, Marotta CA. Outcomes validity and reliability of the modified Rankin scale: implications for stroke clinical trials. Stroke. 2007;38(3):1091-1096. PubMed