Background Corticosteroids (CS) have been identified as a key factor associated with long term damage in systemic lupus erythematosus (SLE). The Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) Damage Index (SDI) has been extensively validated and a previous analysis (Gladman et al J Rheumatol 2003;30:1955–9) suggested that SDI items can be grouped according to their likely association with CS.
Objectives To generate international expert consensus opinion on which SDI items have an association with the use of CS.
Methods We performed a Delphi exercise amongst SLICC members and associates. A survey requested expert opinions on how each SDI item was influenced by CS use on a Likert scale. The scale ranged from -3 to +3 where -3 = I believe that CS have a strong protective link with this item, 0 = I believe that CS have no effect on this item, +3 = I believe that CS have a strong causal link with this item. A second Delphi round presented each participant with their previous rating and the group median for that item, providing the opportunity for revision. A preliminary univariate analysis of CS exposure against damage was performed within the SLICC Inception Cohort to assess the appropriateness of these groupings and if any other items needed reclassifying.
Results Of 43 members/associates, 36 respondents returned 26 complete forms (60.5%). All 26 completed the second round (100%) after which adequate consensus was reached. Four items (cataract, osteoporosis, avascular necrosis and diabetes mellitus) were assessed to be highly likely to be related to CS (median & mode =3, Table 1). Ten other items were “probably”/“possibly” CS related by expert opinion. The remaining items were felt not to be associated with CS. The univariate analysis supported these groupings and identified a significant association between CS exposure and the muscle atrophy/weakness item (e.g. OR (95% CI) 6.81 (1.91–24.27) if on steroids for all of intervening follow up period c.f. some or none of the period). It was agreed that muscle atrophy/weakness should be reclassified into the 'definite association' group.
Conclusions A consensus exercise based on expert opinion and initial analysis in an international inception cohort has generated a preliminary classification of the 42 SDI items according to their likely association with CS. This classification system requires further validation but will facilitate studies examining the impact of CS exposure on SLE populations.
Acknowledgement The Systemic Lupus International Collaborating Clinics (SLICC) acknowledge funding support of UCB Pharma for this study.
Disclosure of Interest None declared