The RAPID3 questionnaire as a screening tool to reduce the number of outpatient clinic visits: a retrospective cohort study

Background: Treat-to-target strategies require frequent on-site evaluations of disease activity in patients with rheumatoid arthritis (RA), burdening patients and caregivers. However, this frequency may not be required in patients in a stable low disease activity state. The Routine Assessment of Patient Index Data 3 (RAPID3) is a reliable tool to detect such states in groups but has not been tested to reduce the frequency of on-site evaluations in individual patient care. In Reade, an outpatient rheumatology clinic, patients can complete the questionnaire online prior to consultation, and the results are directly fed into the electronic patient record. Focusing on low disease activity, we retrospectively studied the test characteristics of RAPID3 and its agreement with the DAS28 in our database of routine patient care. Objective: To assess the test characteristics and agreement between de DAS28 and the RAPID3 in patients with RA, with a focus on the low disease activity categories. Methods: We performed a retrospective database study with available clinical data collected as part of usual care from the electronic medical record at Reade Amsterdam. The dataset comprised RAPID3 assessments followed by a DAS28 within 2 weeks, obtained between June 2014 and March 2021. We dichotomized the disease activity categories for both the RAPID3 and DAS28 into low (remission and low disease activity) and high (moderate and high disease activity). With cutoff values of 2.0 for RAPID3 and 3.2 for DAS28, we calculated test characteristics and agreement (Cohen’s kappa). Results: A total of 5009 combined RAPID3 and DAS28 measurements were done at Reade in 1681 unique RA patients. The mean age was 60 years, and 76% of patients were female with a median disease duration of 4 years. Agreement was considered fair (kappa = 0.26). In total, 1426 (28%) of the RAPID3 measurements were classified as low and could be potentially targeted to skip their consultations. The sensitivity to detect low disease activity was 0.39, specificity was 0.93, and the positive predictive value was 0.92. Conclusion: We showed that when the RAPID3 classifies a patient into low disease activity state, the accuracy is 92%. Of all consultations, 28% could possibly be postponed following the screening with RAPID3.