The assessment and definition of cognitive impairment in patients with systemic lupus erythematosus (SLE) is inconsistent throughout literature; this suggests the need for a consensus to standardize measurement tools and terminology, according to the researchers of a systematic review published in Seminars in Arthritis & Rheumatology.
Cognitive impairment is common in patients with SLE. In 1999, the American College of Rheumatology (ACR) developed a comprehensive, 1-hour neuropsychologic battery that defines cognitive impairment using a threshold of 2 or more standard deviations below the estimated population mean in the domains of attention, memory, and psychomotor speed. The ACR neuropsychologic battery and definition of cognitive impairment have been widely adapted, leading to inconsistencies in the assessment of patients with SLE.
The systematic review was conducted to characterize the measurement tools and definitions to assess cognitive impairment in SLE.
Several databases, including Ovid Medline, Embase, and PsychINFO, were used to search for articles on cognitive impairment in adult patients with SLE. Studies that used a neuropsychologic battery were assessed for alignment with the ACR neuropsychologic battery. Researchers also evaluated the definitions of cognitive impairment and classified the various measurement tools into the following categories: neuropsychologic battery, screening, incomplete/mixed, or computerized.
The literature search yielded 8727 references, of which 118 were selected for a detailed review and 97 were included in this systematic review. Overall, the use of the ACR neuropsychologic battery was inconsistent. When used, it was supplemented with other tests. None of the 43 studies that used a neuropsychologic battery conformed to the ACR neuropsychologic battery as published. Variations were noted in the thresholds and domains used to classify cognitive impairment. Neuropsychologic battery tests were most often used to assess cognitive impairment; however, screening tests and computerized neuropsychologic batteries are increasing in their use.
The main limitation of the study was the difficulty in delineating neuropsychologic battery and non-neuropsychologic battery tools due to the heterogeneity of the tools used.
“As cognition research in SLE continues to grow, it is imperative to develop a comprehensive and standardized methodology for defining and assessing [cognitive impairment] that is both clinically feasible and standardized within the field,” the researchers concluded. “A consensus meeting to address existing inconsistencies should be considered to harmonize the field of [cognitive impairment] in SLE.”
Yuen K, Green R, Bingham K, et al. Metrics and definitions used in the assessment of cognitive impairment in systemic lupus erythematosus: A systematic review. Seminars in Arthritis & Rheumatology. Published online June 9, 2021. doi:10.1016/j.semarthrit.2021.05.018