Breathlessness Assessment
Select the statement that best describes the patient
Assessment Required
The mMRC scale is a primary tool for assessing functional impairment due to dyspnea. Select a grade to see interpretation.
Guidelines & Evidence
Verified
Last Review: 2026-07-09
When to Use
Primary Indications
Assessing breathlessness-related disability in COPD patients
Stratifying patients into GOLD groups A, B, or E (combined with exacerbation history)
Monitoring response to bronchodilators, pulmonary rehabilitation, or lung volume reduction
Predicting mortality (mMRC ≥2 associated with higher risk)
Guiding need for pulmonary rehabilitation (mMRC ≥2 = mandatory referral)
Evaluating disability for work or social benefits
Screening for occult dyspnea in patients with normal spirometry but suspected respiratory limitation
Assessing functional impairment in interstitial lung disease, pulmonary hypertension, and heart failure
Clinical Utility
The mMRC scale correlates strongly with 6-minute walk distance (6MWD) and health-related quality of life (SGRQ). A 1-point increase in mMRC predicts a 30-40m decrease in 6MWD. mMRC ≥2 identifies patients with clinically significant dyspnea who benefit from pulmonary rehabilitation (improves 6MWD by 50-80m). The scale is simple (administered in 1 minute), requires no equipment, and is validated in multiple languages. Unlike the CAT (which measures multi-dimensional symptom burden), mMRC focuses specifically on dyspnea-related physical limitation, making it complementary to CAT for GOLD grouping.
Comparison with Other Dyspnea Scales
| Scale | Items (n) | Administration Time | Validated Populations | Strengths | Limitations |
|---|---|---|---|---|---|
| mMRC | 1 question, 5 grades | 1 minute | COPD, ILD, PH, CHF, post-TB | Simple, fast, predicts mortality/6MWD | Single domain (physical activity only) |
| CAT (COPD Assessment Test) | 8 items, 0-40 scale | 3-5 minutes | COPD | Multi-dimensional (symptoms, energy, sleep, confidence) | Longer, non-specific to dyspnea |
| BDI/TDI (Baseline/Transition Dyspnea Index) | 3 domains (functional, magnitude, effort) | 10-15 minutes | COPD, ILD | Detailed, responsive to change | Time-consuming, requires training |
| UCSD SOBQ | 24 items, 0-120 scale | 10-15 minutes | COPD, ILD | Comprehensive, includes fear/anxiety | Lengthy for clinical practice |
| Borg Scale (modified) | 0-10 numeric rating | 1 minute | Exercise testing (6MWT, CPET) | Captures dyspnea at specific time point | Not a daily activity scale |
Last Comprehensive Review: 2026