Background/Purpose: Triple therapy (MTX, sulphasalazine (SSZ), hydroxychloroquine (HCQ)) has evidence to support its use from randomized trials (RCTs) but is not commonly used. The objective of this study was to quantify rheumatologists’ beliefs about the effectiveness of common initial MTX-based treatment approaches for early rheumatoid arthritis (RA).

Methods: Rheumatologists completed a Bayesian belief elicitation exercise using a validated approach. In 1-on-1 interviews, each rheumatologist was asked to consider the probability that a typical patient with moderate-severe early RA would have an ACR50 response within 6 months, with each of 4 treatments: oral MTX, subcutaneous (sc) MTX, MTX + HCQ, or triple therapy. Rheumatologists were asked to think how they would typically use these treatments in practice, including their preferred dosing and use of any additional treatments (steroids, NSAIDs). In the belief elicitation exercise, participants were given 20 chips, each representing 5% of their total weight of belief. They were asked to distribute the 20 chips across a grid of possible values of the probability of an ACR50 response, placing more chips on values they believed more likely. The parametric distributions best fitting the chip counts were used to calculate pairwise relative risks for each participant. These distributions were averaged for the overall group and separately for subgroups that had optimistic or pessimistic beliefs regarding the relative effect of triple therapy to oral MTX (top and bottom quartiles).

Results: The 38 rheumatologists who completed the belief elicitation exercise were from a variety of practice types (50% academic, 26% community, 24% both). The practice duration ranged from 1-42 years and 58% were female. The overall pooled RR for was highest for triple therapy vs. MTX (Table 1): relative risk (RR), median (95% credible interval): 1.87 (0.74-6.54). Triple therapy, however, was similar in perceived effectiveness to MTX + HCQ [RR 1.11 (0.34-1.79)]. For the optimistic subgroup, both triple therapy and MTX + HCQ were perceived as statistically superior to oral MTX [RR for triple therapy: 2.35 (1.47-6.84); RR for MTX+HCQ: 1.90 (1.19-6.33)], and similar to each other [RR triple therapy vs MTX+HCQ: 1.14 (0.85-1.87)]. Subcutaneous MTX was perceived as more effective than oral MTX, although the credible interval was wide. The pessimistic subgroup perceived all treatments to be similar.

Conclusion: There is variation in rheumatologists’ beliefs regarding MTX-based DMARD treatments. Many consider triple therapy to be effective, but similar to other treatments, particularly MTX + HCQ, for which little RCT evidence exists. This may explain the low use in practice, and supports a randomized trial evaluating these treatments.