Background The wording and form of the patient global assessment (PGA) question may influence the response and thus whether or not a patient meets the ACR/EULAR criteria for remission.
Objectives To assess the effect of the definition of PGA on the classification of ACR/EULAR remission and minimal diseae activity in RA patients after starting etanercept.
Methods We recently found a low impact of 3 different definitions of PGA on the evaluation of disease activity based on the DAS28 (Disease activity Score) in 108 active RA patients treated with etanercept for 12 weeks. One definition focused on general health over the last 2-3 weeks, one on disease activity over the last 48 hours, and the final definition comprised the result of the RA Impact of Disease questionnaire (RAID), a weighted mean of 7 questions, one on each of the domains pain, function, fatigue, physical and psychological well being, sleep disturbance and coping. All were assessed on 0-10 numerical rating scales. The current analysis focuses on ACR/EULAR remission. We also studied the effects on patients with a DAS28 <2.6. This was previously termed remission but is better defined as minimal disease activity.
Results Overall, depending on the chosen definition the number of patients in remission was between 9 and 12 (i.e., about 10%)for ACR/EULAR remission and about 26-27 patients (25%) for minimal disease activity. The definition of PGA had little impact on the cases classified in the Boolean or SDAI (Simple Disease Activity Index) definition, with 2-3 discrepant cases per comparison, and kappa coefficients ranging between 0.82 and 0.89. Keeping the PGA definition stable, the impact of using the Boolean or SDAI definition was larger: 4-6 discrepant cases, kappa 0.67-0.80. For minimal disease activity, there were 2-3 discrepant cases between PGA definitions (kappa 0.92-0.95).
Conclusions In this dataset the definition of PGA had little impact on the classification of patients in ACR/EULAR remission or in minimal disease activity state.
Dougados M, Ripert M, Hilliquin P, et al. The influence of the definition of patient global assessment in assessment of Disease Activity According to the Disease Activity Score (DAS28) in rheumatoid arthritis. J Rheumatol 2011;38:2326-8.
Wells GA, Boers M, Shea B, et al. Minimal disease activity for rheumatoid arthritis: a preliminary definition. J Rheumatol 2005;32:2016-24.
Disclosure of Interest M. Boers: None Declared, Y. Brault Employee of: Pfizer SAS, France, I. Logeart Employee of: Pfizer SAS, France, M. Dougados Grant/Research support from: Pfizer SAS, France