Disease activity measures

In this study, disease activity was defined in two ways by two different instruments which were completed at each visit by the senior author. The PGA, reflecting the clinician's judgement of the disease activity, was scored, prior to reviewing the complement and anti-DNA antibody results, on a 3 cm visual analogue scale, with anchors at 0 for no disease activity, 1 mild, 2 moderate and 3 severe active disease.¹² The M-SLEDAI, a validated and reliable instrument for disease activity omitting the serology items (complement levels, anti-dsDNA antibodies), was used in the present analysis in order to allow comparison with PGA.

M-SLEDAI was scored, based on the presence or absence of disease manifestations during the 10 days prior to the visit.