Metrics and definitions used in the assessment of cognitive impairment in systemic lupus erythematosus: A systematic review

Objective: To review: 1) degree of conformity to the American College of Rheumatology neuropsychological battery (ACR-NB) among studies that used a NB, 2) review definitions of cognitive impairment (CI) from studies that used a NB, and 3) characterize measurement tools used to assess CI in systemic lupus erythematosus (SLE).

Methods: The literature search was conducted in Ovid Medline, Embase, and PsycINFO for articles on CI in adult SLE patients. We reviewed studies that used a NB and compared their tests to the ACR-NB to assess the degree of conformity. Definitions of CI from studies that used a NB were reviewed when sufficient information was available. We reviewed and categorized CI measurement tools into four broad categories: NB, screening, incomplete/mixed batteries, and computerized batteries.

Results: Of 8727 references, 118 were selected for detailed review and 97 were included in the final analysis. Of 43 studies that used a NB, none of the studies used the ACR-NB exactly as published. Many studies supplemented with other tests. Overall, there was inconsistent use of ACR-NB tests. Definitions for CI varied, with cut-offs ranging from 1 to 3 standard deviations below normative values on domains/tests varying in type and number. The most frequently used measurement tool for assessing CI in SLE was a NB. Use of screening tests and computerized batteries have also increased over the last decade.

Conclusion: The assessment and definition of CI in SLE remains heterogeneous. A consensus meeting to address existing inconsistencies should be considered to harmonize the field of CI in SLE.