Evaluation of DMARD effect

1. ACR improvement criteria¹⁹⁸

• tender joint count*
• swollen joint count*
• at least three of:
  • global disease activity - investigator
  • global disease activity - patient**
  • patient assessment of pain
  • physical disability score, e.g. HAQ
  • acute phase reactant

ACR 20, ACR 50 and ACR 70 indicate 20%, 50% and 70% improvement in the above.

* extent of synovitis is measured by doing a count of number of tender joints and number which are both swollen and tender.
** patient opinion of disease activity measured on a 10cm visual analogue scale. Anchor points at either end of the scale are 'not active at all' and 'extremely active'.

2. EULAR response criteria ¹⁹⁹

Disease activity score (DAS) is derived using a nomogram which incorporates the following four measures:

• Ritchie articular index²⁰⁰
• swollen joint count
• ESR (Westergren)
• general health score

DAS >2.8 is usual level of activity for enrolment in DMARD studies

Interpretation of change in disease activity score (DAS) from baseline evaluation of response:

>1.2 good
>0.6 moderate =< 1.2
=< 0.6 non-responder

3. Radiological assessment

Sharp method²⁰¹ (scores erosions and joint space narrowing)
Larsen method²⁰² (utilises standardised films that illustrate progressive destructive disease)