Background/Purpose

In clinical practice, patients with RA are usually seen every 3 to 6 months¹. Although desirable, monthly visits with assessments of disease activity are often not possible due to limited physician resources². However, patients increasingly wish to be actively involved in treatment decisions. Therefore, the development of an internet-based tool for disease activity score assessments by patients could represent an innovative solution. The COmPASS study aims to demonstrate a correlation between the patient assessments of RA disease activity via smartphone and the disease activity done by the physician using traditional scores.

Methods

Adult RA patients under current non-intravenous DMARD treatment were included in the prospective, single-arm, multicentre study. Patients were equipped with smartphones and educated to use a web application (WebApp) for self-assessment. Patients were assessed clinically by the treating physician at baseline. The assessment included joint counts, global assessment, laboratory values, along with simultaneous WebApp questionnaires (RAPID3/4) that were filled in by the patient. During the subsequent 3 months, patients were asked to fill in the WebApp questionnaires at least once a week. Descriptive statistics for RA disease activity according to the WebApp and rheumatologist evaluation at the baseline visit were analysed with the Pearson Correlation. Sensitivity analysis was performed. The correlation between RAPID3/4 scores and DAS44 as well as CDAI and SDAI was evaluated.

Results

Ninety patients were recruited in five Swiss clinics [mean (SD): RA duration: 7.1 years (8.6); age: 54.7 years (13.5); 60% male]. The data showed a strong correlation between patient and rheumatologist assessment of disease activity when comparing RAPID3 with DAS44 at baseline (Fig 1, R=0.60; 95% CI 0.43 – 0.73), CDAI (R=0.53; 95% CI 0.34 – 0.68) and SDAI (R=0.49; 95% CI 0.28 – 0.65). The sensitivity analysis demonstrated that this correlation was independent of disease characteristics, treatment type, demographics, and centre effects, as well as unaffected by a delay of the smartphone data entries up to 7 days after baseline assessment by the rheumatologist. A similar correlation was seen for RAPID4 and DAS44 (R=0.61; 95% CI 0.45 – 0.74), CDAI (R=0.55; 95% CI 0.37 – 0.70) and SDAI (R=0.50; 95% CI 0.30 – 0.66).

Conclusion

In this multicentre study patients’ self-assessment of disease activity (RAPID3 and 4) correlated strongly with that of rheumatologists (DAS44, CDAI, SDAI), indicating that patients are able to self-assess their disease activity. This provides a rationale to further explore the use of smartphone technology for tight disease monitoring in order to help the rheumatologist to optimize RA management. Whether or not the use of a WebApp for self-assessment will lead to better treatment outcomes will have to be shown in future studies.

Figure 1: Pearson Correlation at Baseline – RAPID3 and DAS44 at baseline as primary endpoint