Metrics of Damage in SLE

Measuring damage, defined as irreversible organ dysfunction occurring from the time of SLE disease onset, is essential to both prognostication and management of disease. As SLE is a multisystem, complex illness that varies with time, accurate assessment of damage relies on the use of standardized instruments with demonstrable psychometric properties. In this chapter, we explore the development of the SLICC/ACR damage index (SDI) and appraise the instrument’s psychometric properties including validity measure, reliability, sensitivity to change, and predictive ability. With recognition of the SDI as the most widespread tool in assessing damage in SLE, we conclude the chapter with potential amendments to strengthen the tool. Areas for further consideration include incorporation of novel descriptors, further psychometric testing of current SDI descriptors, a weighted scoring approach to items, and identifying items attributable to glucocorticoid use.