Intraindividual Change in Cognitive Function Among Adults With Systemic Lupus Erythematosus: A Markov Analysis Over 7 Years

Abstract

Objective: Cognitive impairment is prevalent in systemic lupus erythematosus (SLE). There remain gaps in understanding cognition and SLE longitudinally. We studied intraindividual change in cognition in SLE over time.

Methods: Data were from the University of California, San Francisco Lupus Outcome Study, which included 1281 adults with SLE. The Hopkins Verbal Learning Test-Revised (HVLT-R) and the Controlled Oral Word Association Test (COWAT) were administered annually over 7 years. A two-state Markov analysis was used to model transition intensities for probabilities of change in cognition. Logistic regression examined the association between clinical variables and cognitive change.

Results: Minimal transition between cognitive states was observed in the Markov analysis. Using the COWAT, higher levels of self-reported depression were associated with decreased likelihood of cognitive improvement (Relative Risk [RR]: 0.98; 95% confidence interval [CI]: 0.96-0.99), and higher self-reported disease severity was associated with cognitive decline (RR: 1.05; 95% CI: 1.02-1.09). Using the HVLT-R, increasing age (RR: 1.02; 95% CI: 1.01-1.03) and higher education level (RR: 1.82; 95% CI: 1.28-2.58) were associated with cognitive improvement, and higher self-reported disease severity (RR: 1.02; 95% CI: 1.01-1.03) and depression (RR: 1.05; 95% CI: 1.03-1.07) were associated with cognitive decline.

Conclusion: Most individuals with SLE did not transition between states of high (Z score ≥ -1.5) or low (Z score < -1.5) cognition in a Markov analysis over a 7-year assessment period, highlighting a degree of relative stability in cognition over time. Increasing age and higher education levels were associated with greater likelihood of cognitive improvement. Greater self-reported SLE disease severity and depression were associated with cognitive decline.

Figure 1

Two‐state reversible Markov model for the Hopkins Verbal Learning Test‐Revised and Controlled Oral Word Association Test to model the probabilities of transition between higher and lower cognitive states.

Figure 2

Four‐state reversible Markov model to model the association between the Hopkins Verbal Learning Test‐Revised (HVLT‐R) and Controlled Oral Word Association Test (COWAT) over time.