Objective: To identify the optimal initial treatment strategy for knee monarthritis in juvenile idiopathic arthritis (JIA) using a decision model and parents' preferences.
Methods: We utilized a decision analysis model with Markov states and a 6-month multi-attribute outcome with 7 dimensions pertinent to the treatment decision. The 3 most common treatment strategies for knee monarthritis were compared: nonsteroidal antiinflammatory drugs (NSAIDs) only, NSAID trial followed by intraarticular corticosteroid injection (IACI) if arthritis was not resolved after 2 months, and initial IACI. Probability estimates for the efficacy and adverse effects of NSAIDs and IACIs were derived from a systematic review of the literature. Parents' preferences for the 7 dimensions of the multi-attribute outcome were elicited by a unique hybrid of the time tradeoff and magnitude estimation techniques. These preferences were then combined with the outcomes of the decision analysis to determine an individual's preferred treatment.
Results: The NSAID trial strategy may avert IACIs in some patients, but at a cost of continued active arthritis. The number of patients that need to be treated with the NSAID trial strategy to avoid a single IACI compared with the initial IACI strategy is 3.8 with an expected additional cost of 6.7 months of active arthritis. Of the 12 parent subjects, 11 (92%) preferred the initial IACI strategy and 1 preferred the NSAID-only strategy. These preferences were not sensitive to model assumptions or probability estimates.
Conclusion: Initial IACI appears to be the optimal treatment strategy for knee monarthritis in JIA.