22/06/2011 DAS – pros, cons and how to do it Dr Henry Penn Consultant Rheumatologist NWLH Introduction Follow up patients CTD Inf Arth Metabolic Other MSK OA/pain MSK Metabolic OA/pain Inf Arth Other CTD 1 22/06/2011 RA • Approx 500,000 RA cases in the UK • Incidence 2.5/10,000 per year – ie 125 per year in this trust catchment area • 2.5 F : 1 M Diagnosing RA – the old way • ACR Classification criteria Diagnostic criteria - old (4 or more for>6 weeks) – – – – – – – Symmetry >3 joints Wrists/hands EMS>60mins Rheumatoid factor Rheumatoid nodules Erosions 2 22/06/2011 New classification criteria • Target population : Patients who • 1) have at least 1 joint with definite clinical synovitis (swelling) • 2) with the synovitis not better explained by another disease • Classification criteria for RA (scorebased algorithm: add score of categories A–D;a score of 6/10 is needed for classification of a patient as having definite RA) • A. Joint involvement – – – – – 1 large joint 2-10 large joints 1-3 small joints (with or without involvement of large joints)# 4-10 small joints (with or without involvement of large joints) 10 joints (at least 1 small joint)** 0 1 2 3 5 • B. Serology (at least 1 test result is needed for classification) – Negative RF and negative ACPA – Low-positive RF or low-positive ACPA – High-positive RF or high-positive ACPA 0 2 3 • C. Acute-phase reactants (at least 1 test result is needed for classification) – Normal CRP and normal ESR – Abnormal CRP or abnormal ESR 0 1 • D. Duration of symptoms – 6 weeks – 6 weeks 0 1 3 22/06/2011 DAS scores • VAS • ESR/CRP • 0 Remission 2.6 Mild 3.2 Moderate 5.1 Severe Guess the DAS • • • • • New RA SJC 12 TJC 10 ESR 35 VAS 30 • DAS 4 22/06/2011 Guess the DAS • • • • • New RA SJC 12 TJC 10 ESR 35 VAS 30 • DAS 5.65 History of the DAS score • Developed in a trial comparing possible disease measures with rheumatologists actions • Initially in early artritis; then replicated in 9 year study • High activity = DMARD increase or change • Low activity = DMARD stop/no change for 1 year • range 0-10 (DAS 29 4.7 and 9.4) • Designed to have a normal distribution • Inter observer correlation of 0.89 5 22/06/2011 Clinical correlates • Disability • Joint damage • Area under the curve predicts joint damage Guess the DAS • Your classic fibromyalgic lady from a LDC • • • • VAS 85 (on a good day) ESR 45 (although CRP 5) SJC 0 TJC 14 • DAS 6 22/06/2011 Guess the DAS • Your classic fibromyalgic lady from a LDC • • • • VAS 85 (on a good day) ESR 45 (although CRP 5) SJC 0 TJC 14 • DAS 5.95 (CRP 4.89) Guess the DAS • Young man I saw this morning • • • • TJC 0 SJC 6 VAS 20 ESR 2 • DAS 7 22/06/2011 Guess the DAS • Young man I saw this morning • • • • TJC 0 SJC 6 VAS 20 ESR 2 • DAS 1.45 So what are the pitfalls? 8 22/06/2011 So what are the pitfalls? • VAS • Chronic pain syndrome – 5% or more RA – Catastrophisation – Pain scores lower in men - ? undertreated So what are the pitfalls? • Feet – We all see patients in whom the feet are most affected – Could do DAS 44 9 22/06/2011 So what are the pitfalls? • Bloods – ESR may be high persistently, especially in those from a less developed nation – Some RA cases have persistently normal CRP – Is the DAS CRP the same as the DAS ESR? 10