Longitudinal Occurrence and Predictors of Patient-Provider Discordance Between Global Assessments of Disease Activity in Rheumatoid Arthritis: A Case-Control Study.

OBJECTIVE: To identify longitudinal predictors of discordance between patients with rheumatoid arthritis (RA) and their health care providers, where patient global assessment of disease activity is substantially higher than provider global assessment. METHODS: This retrospective case-control study included 102 cases with positive discordance (i.e., ≥25 mm between patient and provider global assessments) and 102 controls without discordance who were matched for age, sex, RA duration, and Clinical Disease Activity Index (CDAI) score. Data were collected at the baseline visit (date of diagnosis or earliest available visit), the index visit (participation in a previous cross-sectional study), and at up to 11 additional visits before the index visit. Data included patient characteristics, disease activity measures, Disease Activity Score in 28 joints (3-variable) using the C-reactive protein level (DAS28-CRP), and medications. Data were analyzed by using linear and logistic regression models with smoothing splines for nonlinear trends. RESULTS: Overall, the mean age was 63 years, 75% of patients were female, and the mean RA duration was 10 years. Compared with controls, cases had higher rates of discordant visits during the 4 years before the index visit, and they had a higher CDAI score and DAS28-CRP earlier in the disease course. Cases more frequently had antinuclear antibodies, nonerosive disease, prior depression, or prior use of antidepressants or fibromyalgia medications. Disease-modifying medication use was not different between cases and controls. CONCLUSION: The findings inform new hypotheses about the relationships of disease activity and antinuclear antibodies to the later occurrence of positive discordance among patients with RA.

The Patient Global Assessment of Disease Activity in Rheumatoid Arthritis: Identification of Underlying Latent Factors.

INTRODUCTION: The patient global assessment of disease activity is a crucial component of various measures of disease activity in rheumatoid arthritis (RA). Our objective was to identify underlying latent traits driving the patient global assessment using a quantitative, multivariable data reduction approach. METHODS: This was a prospective cross-sectional study of consecutive patients with RA. The patient sample was stratified to include 50 patients with patient-provider discordance (i.e., at least 25-mm absolute difference between the patient and provider global assessments) and 20 patients with patient-provider concordance (i.e., less than 25-mm absolute difference between the patient and provider global assessments). Data were collected from the most recent rheumatology visit, including patient characteristics, current RA medications, and comorbidities. Participants completed several validated patient-reported outcome measures. The data were evaluated using factor analysis, and then linear regression was used to determine the variability in the patient global assessment explained by the factor scores. RESULTS: The study included 70 patients with mean age of 61 years, 73% female, and with mean disease duration of 8 years. The means (SD) for the patient and provider global assessments were 44.6 (22.7) and 20.1 (17.7), respectively. Factor analysis yielded eight factors that represented measurements of pain, fatigue, depression or anxiety symptoms, prior diagnosis of depression or anxiety, advanced age and degenerative arthritis, inability to participate, fibromyalgia (clinical diagnosis and Widespread Pain Index), and undetermined. Linear regression analysis showed that fibromyalgia explained the greatest proportion of the variance in the patient global assessment followed by the other factors. CONCLUSION: Latent factors underlying the patient global assessment include pain, depression and anxiety, inability to participate, fibromyalgia, advanced age, and degenerative arthritis.