To elaborate a clinical practice decision tree for the choice of the first disease modifying antirheumatic drug (DMARD) for untreated rheumatoid arthritis of less than six months' duration.
Four steps were employed: (1) review of published reports on DMARD efficacy against rheumatoid arthritis; (2) inventory of the information available to guide DMARD choice; (3) selection of the most pertinent information by 12 experts using a Delphi method; and (4) choice of DMARDs in 12 clinical situations defined by items selected in step 3 (28 joint disease activity score (DAS 28): < or =3.2; >3.2 and < or =5.1; >5.1; rheumatoid factor status (positive/negative); structural damage (with/without)-that is, 3 x 2 x 2). Thus, multiplied by all the possible treatment pairs, 180 scenarios were obtained and presented to 36 experts, who ranked treatment choices according to the Thurstone pairwise method.
Among the 77 items identified, 41 were selected as pertinent to guide the DMARD choice. They were reorganised into five domains: rheumatoid arthritis activity, factors predictive of structural damage; patient characteristics; DMARD characteristics; physician characteristics. In the majority of situations, the two top ranking DMARD choices were methotrexate and leflunomide. Etanercept was an alternative for these agents when high disease activity was associated with poor structural prognosis and rheumatoid factor positivity.
Starting with simple scenarios and using the pairwise method, a clinical decision tree could be devised for the choice of the first DMARD to treat very early rheumatoid arthritis.