Rheumatology Calculators

Disease Activity Score in 28 joints for monitoring rheumatoid arthritis. Used to guide DMARD escalation and biologic eligibility.

Clinical Disease Activity Index for RA — does not require lab tests, making it useful at point of care.

ACR/EULAR 2015 classification criteria for gout. Score ≥8 classifies as gout.

2019 ACR/EULAR classification criteria for SLE. Requires positive ANA (entry criterion). Score ≥10 classifies as SLE.

Simplified criteria for diagnosing reactive arthritis (formerly Reiter's syndrome). Asymmetric oligoarthritis following infection.

Simplified FRAX-based osteoporosis risk assessment. Full FRAX requires BMD; this tool identifies candidates for DXA scanning.

Classification criteria for psoriatic arthritis (PsA). Requires inflammatory articular disease + score ≥3.

Simplified scoring for ANCA-associated vasculitis (GPA/Wegener's). Score ≥5 classifies as GPA.

Systemic Lupus Erythematosus Disease Activity Index 2000. 24-item weighted score measuring disease activity across 9 organ systems in the preceding 10 days.

2010 ACR/EULAR criteria for classifying definite rheumatoid arthritis. Score ≥ 6/10 = definite RA. Applicable to patients with ≥ 1 joint with clinical synovitis not better explained by another diagnosis.

6-question patient-reported outcome measuring disease activity in axial spondyloarthritis (ankylosing spondylitis). Score ≥ 4 indicates active disease — biologic eligibility threshold.

ACR/EULAR 2012 provisional criteria for classifying PMR in patients ≥50 years with new bilateral shoulder aching and elevated acute phase response. Score ≥4 (without USS) or ≥5 (with USS) = PMR classification.

2016 ACR/EULAR criteria for classifying primary Sjögren's syndrome in patients with ocular or oral dryness (or positive anti-SSA). Score ≥4 = primary Sjögren's syndrome.

Assessment of SpondyloArthritis International Society (ASAS) classification criteria for axial SpA in patients with chronic back pain ≥3 months onset age <45 years. Includes radiographic (AS) and non-radiographic axial SpA.

Modified Jones Criteria (2015 AHA) for diagnosing first episode of acute rheumatic fever (ARF). Requires evidence of preceding streptococcal infection PLUS major/minor criteria as specified.

ASTCT 2019 consensus grading of cytokine release syndrome (CRS) following CAR-T cell therapy, bispecific antibodies, or other immunotherapy. Grade 1–4. Guides management with tocilizumab and corticosteroids.

Patient-reported outcome measure for RA disease activity. Combines HAQ-II (disability) and patient global VAS. Score 0–10. Validated and recommended by ACR for routine RA monitoring. Correlates with DAS28 and CDAI.

2015 ACR/EULAR classification criteria for gout. Based on clinical, laboratory, and imaging evidence. Score ≥8 = gout classified. Gold standard = urate crystals in joint fluid, but scoring system available when unavailable.

Calculates age-adjusted upper limit of normal for Erythrocyte Sedimentation Rate (ESR). Rule: Male = age/2; Female = (age + 10)/2. Useful for PMR, GCA, and other inflammatory conditions where absolute ESR value may be misleading without age context.

Measures rheumatoid arthritis disease activity using 28 joint counts (tender and swollen), CRP, and patient global assessment. Guides DMARD therapy.

Classifies rheumatoid arthritis using 2010 ACR/EULAR criteria. Score >=6 = definite RA. Replaces 1987 criteria; captures early RA.

Measures SLE disease activity across 24 clinical features. Guides treatment escalation and monitoring in systemic lupus erythematosus.

Patient-reported outcome measuring disease activity in ankylosing spondylitis and axial spondyloarthropathy. BASDAI >=4 indicates high disease activity.

Classifies polymyalgia rheumatica (PMR) using EULAR/ACR 2012 provisional classification criteria. Score >=4 (without US) or >=5 (with US) = PMR.

Classification criteria for psoriatic arthritis (PsA) using the CASPAR criteria. Score >=3 with inflammatory articular disease = PsA.

Measures disease activity in ANCA-associated vasculitis (GPA, MPA, EGPA) across nine organ systems. Guides immunosuppressive therapy.

Diagnoses reactive arthritis (formerly Reiter syndrome) using clinical triad and preceding infection evidence. Guides NSAID, antibiotic, and disease-modifying therapy.