Analysis of patient-physician discrepancy in global assessment of systemic autoimmune myopathy disease activity

To compare the perception of disease activity (DA) between adult patients with systemic autoimmune myopathies (SAMs) and their physicians, and analyse possible sources of discordance.

This cross-sectional study included 75 patients with SAMs. Patients and physicians rated the global DA on a 0-10 cm visual analogue scale. A discrepancy score was calculated by subtracting physician assessment from patient assessment. Three groups were defined: (I) no discrepancy: difference within -2.0 to +2.0; (II) negative discrepancy (ND): difference <-2.0 (patient underrated DA in relation to physcian); (III) positive discrepancy (PD): difference >+2.0 (patient overrated DA in relation to physician). Logistic regression was used to identify predictors of discordance.

Discordance in patient-physician assessment of DA was found in 21 (28%) cases. ND was observed in 3 (4%), PD in 18 (24%), and no discrepancy in 54 (72%) assessments. Due to the small number, ND cases were excluded from the analysis. PD was associated with older age, personal history of depression, past joint involvement, higher MMT-8 and lower extramuscular DA. In the regression model, for each additional year of age, the chance of PD increases, on average, by 9% (OR 1.09; 95%CI 1.01-1.17, p=0.034). Personal history of depression increases the chance of PD by 829% (OR 9.29; 95%CI 1.52-56.89, p=0.016).

Almost 30% of patients had discordance in DA assessment from their physicians. The majority of them overrated their DA. These patients tend to be older and are more likely to have personal history of depression, past joint involvement, and milder disease.