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Rheumatology Calculators
Organized by Condition

Every validated scoring tool, classification criteria, and functional assessment - organized by condition so you find what you need in one click. Evidence-based, formulaically accurate, free.

Rheumatoid Arthritis
RA Assessment Suite
The complete set of validated tools for classifying, monitoring disease activity, and measuring functional outcomes in rheumatoid arthritis. DAS28-CRP is the standard for treat-to-target monitoring and biologic authorization.
Treat-to-target goal: DAS28-CRP < 2.6 7 validated instruments ACR/EULAR endorsed
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Activity Scores
🎯 Classification Criteria
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RA Classification Criteria
2010 ACR/EULAR
Scores joint involvement (0-5), serology (0-3), acute phase reactants (0-1), and symptom duration (0-1). A score of 6 or more classifies as definite RA. Replaced the 1987 criteria to enable earlier diagnosis.
Aletaha et al., 2010 →
📊 Disease Activity
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DAS28-CRP
Disease Activity Score (CRP)
The most widely used RA disease activity score. Combines 28-joint counts, patient global VAS, and CRP via a validated formula. Standard for treat-to-target monitoring. Preferred over ESR version in most modern practice.
Fransen & van Riel, 2003 →
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DAS28-ESR
Disease Activity Score (ESR)
The original DAS28 formula using erythrocyte sedimentation rate. Required for some biologic prescribing pathways. Runs ~0.6 points higher than DAS28-CRP in the same patient. Used in most early RA clinical trials.
Prevow et al., 1995 →
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CDAI
Clinical Disease Activity Index
No laboratory values required. Sums TJC28 + SJC28 + physician global (0-10) + patient global (0-10). Maximum 76. Remission threshold of 2.8 is more stringent than DAS28. Ideal for point-of-care assessment.
Aletaha & Smolen, 2005 →
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SDAI
Simplified Disease Activity Index
Adds CRP (in mg/dL) to the CDAI components. Simple linear sum with no logarithms. Maximally transparent - you can see exactly which variable is driving the score. Note: uses mg/dL, not mg/L.
Smolen et al., 2003 →
🤲 Functional / Patient-Reported
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RAPID3
Routine Assessment of Patient Index Data
Three-part patient-reported outcome: 10-item function score, pain VAS, and patient global. Requires no joint exam or labs. Completes in under 60 seconds. Validated against DAS28 for longitudinal monitoring. Not for biologic prescribing.
Pincus et al., 2008 →
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HAQ-DI
Health Assessment Questionnaire
Gold standard functional disability measure in rheumatology. Eight domains covering daily activities. Scores 0-3. HAQ above 1.0 independently predicts mortality. A component of ACR/EULAR Boolean remission criteria (HAQ ≤ 0.5).
Fries et al., 1980 →
Systemic Lupus Erythematosus
Lupus Assessment Suite
Tools for classifying SLE, monitoring disease activity, and tracking cumulative organ damage. SLEDAI-2K is the standard endpoint in all major lupus trials including BLISS and TULIP. A 4-point SLEDAI reduction (SRI-4) defines treatment response.
SRI-4 response: SLEDAI decrease ≥ 4 ANA required for 2019 criteria EULAR/ACR endorsed
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Max SLEDAI
🎯Classification Criteria
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SLE Classification Criteria
2019 EULAR/ACR
Requires ANA ≥ 1:80 as mandatory entry criterion. Seven weighted domains with max-only scoring per domain. A score of 10 or more classifies as SLE. Sensitivity 96.1%, specificity 93.4% in the validation cohort of 13,000+ patients.
Aringer et al., 2019→
📊Disease Activity
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SLEDAI-2K
SLE Disease Activity Index 2000
24 weighted clinical and laboratory features across 9 organ domains. The standard endpoint in lupus trials (belimumab BLISS, anifrolumab TULIP, voclosporin AURORA). The 2K update allows persistent features to continue scoring at follow-up visits.
Gladman et al., 2002→
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Lupus Physician Global Assessment
Lupus PGA (0-3 VAS)
The physician-anchored 0-3 visual analogue scale that is a required component of the SRI-4 and SRI-50 response criteria. No worsening of PGA is required alongside the SLEDAI-2K improvement to define a responder in major lupus trials.
Furie et al., BLISS-76→
Spondyloarthritis & Psoriatic Arthritis
SpA / PsA Assessment Suite
ASDAS-CRP is now the preferred ASAS/EULAR 2022 instrument for axial SpA, preferred over BASDAI for its objectivity. BASDAI remains widely used when CRP is unavailable. DAPSA is the validated composite for psoriatic arthritis disease activity.
ASDAS-CRP preferred over BASDAI (ASAS 2022) BASDAI ≥ 4: active disease DAPSA remission: ≤ 4
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Tools
2022
Last Updated
🎯Classification Criteria
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CASPAR Criteria for PsA
ClASsification criteria for Psoriatic ARthritis
Five-item scoring system for classifying inflammatory arthritis as psoriatic. Requires inflammatory articular disease plus a score of 3 or more. Includes psoriasis history (2 pts), nail disease, dactylitis, RF negativity, and radiographic features.
Taylor et al., 2006→
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Axial SpA Criteria
ASAS Classification
Two arms for classifying axial spondyloarthritis: imaging arm (sacroiliitis on MRI or X-ray plus one SpA feature) or clinical arm (HLA-B27 plus two or more SpA features). Covers both AS and non-radiographic axial SpA.
Rudwaleit et al., 2009→
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Peripheral SpA Criteria
ASAS Classification
Entry requires current arthritis, enthesitis, or dactylitis. Set A: one or more high-specificity SpA features (psoriasis, IBD, preceding infection, uveitis, HLA-B27, sacroiliitis). Set B: two or more additive features. Covers peripheral-predominant SpA.
Rudwaleit et al., 2011→
📊Disease Activity
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ASDAS-CRP
AS Disease Activity Score
Composite score combining back pain, morning stiffness, peripheral pain/swelling, patient global, and CRP. Preferred by ASAS 2022 over BASDAI for its objectivity. Inactive < 1.3 | Moderate 1.3-2.1 | High 2.1-3.5 | Very High ≥ 3.5.
Lukas et al., 2009→
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BASDAI
Bath AS Disease Activity Index
Six patient-reported questions on fatigue, spinal/hip/neck pain, peripheral joint pain, entheseal tenderness, and morning stiffness. Score of 4 or more historically indicated active disease. No labs required. Used when CRP is unavailable for ASDAS.
Garrett et al., 1994→
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DAPSA
Disease Activity in Psoriatic Arthritis
Five-component sum: tender joint count (68), swollen joint count (66), patient pain VAS, patient global VAS, and CRP. Remission ≤ 4, low ≤ 14, moderate ≤ 28, high > 28. Used in most recent PsA biologic trials as primary endpoint.
Schoels et al., 2010→
🤲Functional Assessment
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BASFI
Bath AS Functional Index
Ten patient-reported questions on ability to perform daily functional tasks. Each scored 0-10. Simple average gives the BASFI score. Validates against physical measurements and correlates with long-term work disability in axial SpA patients.
Calin et al., 1994→
Primary Sjogren's Disease
Sjogren's Assessment Suite
ESSDAI captures systemic organ-domain disease activity; ESSPRI captures the patient's symptom burden. They assess different dimensions - correlations between them are typically low (0.07-0.29). Both are required for comprehensive clinical trial endpoints.
ESSDAI ≥ 5: moderate systemic activity ESSPRI < 5: acceptable symptom state MCID: ESSDAI -3, ESSPRI -1
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ESSDAI Domains
🎯Classification Criteria
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Sjogren's Classification Criteria
2016 ACR/EULAR
Five-item weighted scoring: lip biopsy with focal lymphocytic sialadenitis (3 pts), anti-SSA/Ro (3 pts), ocular staining score (1 pt), Schirmer's test (1 pt), unstimulated whole saliva flow (1 pt). Score ≥ 4 classifies as primary Sjogren's.
Shiboski et al., 2017→
📊Disease Activity & Patient-Reported
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ESSDAI
EULAR Sjogren's Syndrome Disease Activity Index
Systemic disease activity across 12 weighted organ domains (constitutional, lymphadenopathy, glandular, articular, cutaneous, pulmonary, renal, muscular, PNS, CNS, hematological, biological). Low < 5, moderate 5-13, high ≥ 14.
Seror et al., 2010→
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ESSPRI
EULAR Sjogren's Patient Reported Index
Patient-completed average of three 0-10 NRS questions: dryness (mean of ocular and oral), fatigue, and pain. Score = (dryness + fatigue + pain) / 3. Acceptable symptom state defined as score < 5. MCID is 1 point or 15% improvement.
Seror et al., 2011→
Systemic Sclerosis
Scleroderma Assessment Suite
The mRSS is the primary outcome measure in almost all SSc trials. It captures the degree and extent of skin fibrosis and correlates with internal organ involvement, overall disease severity, and survival. Assessment requires physical examination of 17 body areas.
mRSS > 15: severe skin involvement MCID: 3-5 points Primary endpoint in most SSc trials
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Max mRSS
🎯Classification Criteria
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SSc Classification Criteria
2013 ACR/EULAR
Weighted scoring: skin thickening of fingers (9 pts), fingertip lesions, telangiectasia, abnormal nail fold capillaries, SSc-related antibodies (3 pts), ILD or PAH (2 pts each), Raynaud's (3 pts). Score ≥ 9 classifies as SSc.
van den Hoogen et al., 2013→
📊Disease Activity / Skin Assessment
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Modified Rodnan Skin Score
mRSS
Assessment of skin thickness across 17 body areas rated 0 (normal) to 3 (severe). Maximum 51. The validated primary outcome in nearly all diffuse SSc clinical trials. Correlates with survival, cardiopulmonary involvement, and disease progression.
Clements et al., 1995→
Inflammatory Myositis (IIM)
Myositis Assessment Suite
The IMACS core set is the foundation of myositis assessment, combining physician global, patient global, muscle strength (MMT-8), functional assessment (HAQ/MYOACT), laboratory enzymes, and global extramuscular activity. The MMT-8 is the single most important objective measure.
MMT-8 max: 80 points IMACS 2016 response criteria ACR/EULAR 2017 classification
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🎯Classification Criteria
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Inflammatory Myositis Classification
2017 EULAR/ACR
Probability-based score distinguishing IIM from non-IIM and subcategorizing into PM, DM, IBM, JDIM. Includes muscle, skin, laboratory, biopsy, and clinical features. Validated with sensitivity 87% and specificity 82% at the probable threshold.
Lundberg et al., 2017→
📊Muscle Strength & Activity
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MMT-8
Manual Muscle Testing (8 muscle groups)
Standardized manual muscle testing of 8 bilateral proximal, distal, and axial muscle groups. Each graded 0-10 using the IMACS scale. Maximum 80 points. The objective muscle strength component of the IMACS core set. Required for IMACS response criteria.
IMACS, Miller et al. 2001→
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MDGA / PDGA
Physician & Patient Global Disease Activity
Both the physician and patient 0-10 VAS global disease activity assessments are required components of the IMACS core outcome set and the 2016 ACR/EULAR myositis response criteria. Guides minimal, moderate, and major improvement thresholds.
IMACS Core Set, 2004→
ANCA-Associated & Large Vessel Vasculitis
Vasculitis Assessment Suite
The complete 2022 ACR/EULAR vasculitis classification suite covers all major vasculitides -- GPA, MPA, EGPA, PAN, cryoglobulinemic vasculitis, GCA, and TAK -- all validated in the DCVAS dataset across 27 countries. BVAS v3 is the standard disease activity endpoint for AAV trials.
BVAS = 0: complete remission 7 classification criteria 2022 ACR/EULAR validated
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2022
Updated
🎯Classification Criteria
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GPA Classification Criteria
Granulomatosis with Polyangiitis · 2022 ACR/EULAR
Positive and negative weighted items: ENT features (+3), cartilage involvement (+2), retroorbital mass (+2), PR3-ANCA (+5), palisading granuloma (+3). Negative weights for eosinophilia and nasal polyps. Score 5 or above classifies.
Robson et al., 2022→
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MPA Classification Criteria
Microscopic Polyangiitis · 2022 ACR/EULAR
MPO-ANCA or p-ANCA (+6), pulmonary fibrosis (+3), pauci-immune GN (+3). Negative weights for granuloma on biopsy and nasal polyps/cartilage. Score 5 or above classifies as MPA. Sensitivity 91%, specificity 94%.
Suppiah et al., 2022→
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EGPA Classification Criteria
Eosinophilic Granulomatosis with Polyangiitis · 2022 ACR/EULAR
Eosinophilia (+5), airflow obstruction (+3), nasal polyps (+3), tissue eosinophils (+2), extravascular eosinophils on biopsy (+2). PR3-ANCA is a negative weight (-3). Score 5 or above classifies.
Grayson et al., 2022→
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PAN Classification Criteria
Polyarteritis Nodosa · 2022 ACR/EULAR
ANCA-negative medium-vessel vasculitis. Livedo reticularis (+2), orchitis (+2), aneurysm/stenosis/occlusion on angiography (+3), mononeuritis multiplex (+1), HBV (+1). Score 5 or above classifies.
Grayson et al., 2022→
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Cryoglobulinemic Vasculitis Criteria
2022 ACR/EULAR
Cryoglobulins detected (+3), palpable purpura (+2), HCV (+2), GN (+2), peripheral neuropathy (+1), biopsy vascular deposits (+3), low complement (+1), positive RF (+1). Score 6 or above classifies.
Casal Dominguez et al., 2022→
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GCA Classification Criteria
Giant Cell Arteritis · 2022 ACR/EULAR
Requires confirmed large-vessel vasculitis and age 50 or above. Biopsy/US halo (+5), ESR 50 or above (+3), visual loss (+3), jaw claudication (+2), morning stiffness (+1), temporal artery tenderness (+2). Score 6 or above classifies.
Ponte et al., 2022→
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Takayasu Arteritis Criteria
2022 ACR/EULAR
Requires imaging evidence of large-vessel vasculitis and age 60 or below. Thoracic aorta/branches or pulmonary artery involvement, absent pulse, bruits, asymmetric blood pressure. Score 5 or above classifies.
Grayson et al., 2022→
📊Disease Activity & Damage
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BVAS v3
Birmingham Vasculitis Activity Score
56-item assessment across 9 organ systems. Persistent features score half value. Maximum 63. BVAS = 0 defines complete remission per RAVE, RITUXVAS, MEPEX, and PEXIVAS trial definitions.
Mukhtyar et al., 2009→
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VDI
Vasculitis Damage Index
64-item assessment of irreversible organ damage since diagnosis. Captures damage from both disease activity and treatment toxicity. Higher VDI independently predicts mortality in long-term cohort studies.
Exley et al., 1997→
Crystal Arthropathy
Gout & CPPD Suite
Classification tools for gout (ACR/EULAR 2015, validated in 983 patients) and CPPD (ACR/EULAR 2023, the first-ever validated criteria for calcium pyrophosphate deposition disease). Use for research classification and to support clinical documentation - not as diagnostic replacements.
Gout criteria: sensitivity 92%, specificity 89% CPPD criteria validated 2023
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🎯Classification Criteria
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Gout Classification Criteria
2015 ACR/EULAR
Step 1: MSU crystal identification classifies directly. Step 2: entry criterion (at least one episode of peripheral joint swelling, pain, or tenderness). Step 3: 8-domain scoring system. Score ≥ 8 classifies as gout.
Neogi et al., 2015→
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CPPD Classification Criteria
2023 ACR/EULAR
The first formally validated classification criteria for calcium pyrophosphate deposition disease. Three-tier framework: definite (imaging or synovial fluid), probable, and possible CPPD. Distinguishes from other crystal arthropathies and OA.
Abhishek et al., 2023→
Content reviewed by Mahiar Rabie, MS, MD · AutoimmuneCalc