Validation of potential classification criteria for systemic sclerosis
Bibliographic record
Abstract
OBJECTIVE: Classification criteria for systemic sclerosis (SSc; scleroderma) are being updated jointly by the American College of Rheumatology and European League Against Rheumatism. Potential items for classification were reduced to 23 using Delphi and nominal group techniques. We evaluated the face, discriminant, and construct validity of the items to be further studied as potential criteria. METHODS: Face validity was evaluated using the frequency of items in patients sampled from the Canadian Scleroderma Research Group, 1000 Faces of Lupus, and the Pittsburgh, Toronto, Madrid, and Berlin connective tissue disease (CTD) databases. Patients with SSc (n = 783) were compared to 1,071 patients with diseases similar to SSc (mimickers): systemic lupus erythematosus (n = 499), myositis (n = 171), Sjögren's syndrome (n = 95), Raynaud's phenomenon (RP; n = 228), mixed CTD (n = 29), and idiopathic pulmonary arterial hypertension (PAH; n = 49). Discriminant validity was evaluated using odds ratios (ORs). For construct validity, empirical ranking was compared to expert ranking. RESULTS: Compared to mimickers, patients with SSc were more likely to have skin thickening (OR 427); telangiectasias (OR 91); anti-RNA polymerase III antibody (OR 75); puffy fingers (OR 35); finger flexion contractures (OR 29); tendon/bursal friction rubs (OR 27); anti-topoisomerase I antibody (OR 25); RP (OR 24); fingertip ulcers/pitting scars (OR 19); anticentromere antibody (OR 14); abnormal nailfold capillaries (OR 10); gastroesophageal reflux disease symptoms (OR 8); antinuclear antibody, calcinosis, dysphagia, and esophageal dilation (all OR 6); interstitial lung disease/pulmonary fibrosis (OR 5); and anti-PM-Scl antibody (OR 2). Reduced carbon monoxide diffusing capacity, PAH, and reduced forced vital capacity had ORs of <2. Renal crisis and digital pulp loss/acroosteolysis did not occur in SSc mimickers (OR not estimated). Empirical and expert ranking were correlated (Spearman's ρ = 0.53, P = 0.01). CONCLUSION: The candidate items have good face, discriminant, and construct validity. Further item reduction will be evaluated in prospective SSc and mimicker cases.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.037 | 0.112 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.005 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.003 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".