TY - JOUR T1 - A clinical prediction guide predicted progression to rheumatoid arthritis in undifferentiated arthritis JF - Evidence Based Medicine JO - Evid Based Med SP - 154 LP - 154 DO - 10.1136/ebm.12.5.154 VL - 12 IS - 5 A2 - , Y1 - 2007/10/01 UR - http://ebm.bmj.com/content/12/5/154.abstract N2 - van der Helm-Van Mil AH, le Cessie S, van Dongen H, et al. A prediction rule for disease outcome in patients with recent-onset undifferentiated arthritis: how to guide individual treatment decisions. Arthritis Rheum 2007;56:433–40.OpenUrlCrossRefPubMedWeb of Science 
 
 Q In patients with undifferentiated arthritis, can a prediction rule identify those who will progress to rheumatoid arthritis (RA)? Clinical impact ratings Rheumatology ★★★★★★★ Design: prospective cohort study with independent derivation and validation sets. Setting: an arthritis clinic at a university in the Netherlands. Patients: 570 patients (mean age 51 y, 58% women) with recent onset arthritis formed the derivation cohort. 36 patients with recent onset arthritis in the placebo group of the Probaat (PROMPT) trial formed the validation cohort. Description of prediction guide: the guide had 9 questions: (1) age (× 0.02); (2) sex (1 point for female); (3) distribution of involved joints: small joint hands/feet (0.5 point), symmetric (0.5 point), upper extremities (1 point), upper and lower extremities (1.5 points); (4) score for morning stiffness on a 100-mm visual analogue scale: 26–90 mm (1 point), >90 mm (2 points); (5) number of tender joints: 4–10 … ER -