Variability of patient and physician global assessment on visual analogue and Likert scales in rheumatoid arthritis

Objective. The study aimed to observe the variability of rheumatoid arthritis (RA) disease activity scores according to the type of patient global assessment (PtGA) and to compare these subjective assessments with objective measurements. Methods. Prospective study in which RA patients four types of assessments in the same day of their inclusion in the study: completing a questionnaire (including PtGA on a 100 mm visual analogue scale – VAS, and a 0-10 Likert scale), clinical interview and joint examination performed by each attending rheumatologist and peripheral venous blood sampling for acute phase reactants. Results. The study included 110 RA patients (57.5 years average age, 9.4 years median disease duration, 90.0% women, 58.2% in remission or low disease activity). There was low concordance and agreement between PtGA and physician global assessment (PhGA): the two evaluations were significantly but poorly correlated, and in 71.8% of cases VAS and Likert PtGA were higher than PhGA with at least 2 points in average. Patients with no tender or swollen joints (27.3%) reported a median VAS-PtGA of 27 cm and a median Likert-PtGA of 4.2 points. Likert-PtGA were higher than VAS-PtGA in the general sample and for patients with normal objective measures (patients in remission according to DAS28-3v-CRP reported a median VAS-PtGA of 5 points, compared to VAS-PtGA of only 2.2 cm). The strongest correlations of PtGA on both VAS and Likert scales were recorded for mHAQ (r = 0.521 and 0.589, p < 0.001), DAS28-3v-CRP (r = 0.419 and 0.422, p < 0.001) and the presence of prolonged morning stiffness (r = 0.361 and 0.485, p < 0.001). Conclusion. Romanian patients with RA seem to favour and understand the Likert scale better than the VAS when reporting PtGA.