Background There have been increasing studies focusing on patient derived joint counts in RA. Patient self-reported DAS28 with training has not been observed longitudinally in the UK.
Objectives The aims of the study were to (1) evaluate the reliability of patient self-assessment of DAS28 compared to physician DAS28; (2) determine whether the agreement between patient-reported and physician-reported DAS28 improves over time with training.
Methods This was a longitudinal study with a total of 3 study visits 6 weeks apart carried out at two hospitals sites in the United Kingdom. All 42 patients had training on joint count self-assessment. A single physician performed joints assessment on patients independently blinded to the patients' data. Correlations between patient and physician measurements were analysed using Spearman correlation coefficient whereas agreement between patient and physician was analysed with Bland-Altman plots.
Results There was very strong correlation between patient and physician DAS28-CRP, DAS28-ESR, TJC and SJC (r >0.80). The limits of agreement of DAS28 were consistent (range -0.65 to 0.69) but exceeded the set difference of 0.6, although with very small mean difference.
Conclusions Overall, it is reasonable to conclude that there were good agreement of tender and swollen joint assessments between patient and physician. Patient training has positive effects in increasing the reliability of patient self-assessment of joint counts. Our study showed patient-reported DAS28 was not exactly same as physician-reported DAS28, although DAS28, TJC and SJC from both patient and physician were all very strongly correlated. Patient-reported joint counts were shown to have a strong predictive value and therefore could be incorporated in clinical practice. Patient DAS28 and physician DAS28 could act synergistically to reach a consensus evaluation of RA in order to achieve treatment optimisation.
Acknowledgement Dr Jamie Sergeant, a Lecturer in Statistics, Centre for Musculoskeletal Research, Institute of Inflammation and Repair, the University of Manchester.
Disclosure of Interest None declared