Demographic characteristics and cognitive test results of study groups
| SLE group, N=95 | HC group, N=48 | Comparison* (p value) | |
| Age, median (range) | 45 years (22–64) | 46 years (23–62) | 0.77 |
| Gender, female | 93% | 92% | 0.84 |
| Ethnicity | 0.27 | ||
| Caucasian | 62% | 58% | |
| Asian | 34% | 42% | |
| Other | 4% | 0% | |
| Premorbid IQ†, mean±SD | 108.5±7.3 | 110.8±8.3 | 0.10 |
| Education | 0.14 | ||
| Less than secondary | 12% | 6% | |
| Secondary | 23% | 13% | |
| Tertiary | 54% | 58% | |
| Postgraduate | 12% | 23% | |
| Paid employment | 60% | 92% | 0.001 |
| History of depression | 37% | 6% | <0.001 |
| History of anxiety | 27% | 6% | 0.003 |
| MoCA score, median (range) | 26 (19–30) | 28.5 (21–30) | <0.0001 |
| Individual cognitive domain test scores‡, mean (range) | |||
| Visual memory | 19 (3–32) | 25 (12–33) | <0.0001 |
| Verbal memory | 51 (19–70) | 59 (45–71) | <0.0001 |
| Verbal fluency | 41 (16–80) | 53 (33–84) | <0.0001 |
| Working memory | 18 (9–26) | 21 (16–28) | <0.0001 |
| Processing speed | 69 (33–114) | 84 (44–134) | <0.0001 |
| Complex attention | 80 (29–267) | 57 (30–153) | <0.0001 |
| Psychomotor speed | 146 (89–193) | 156 (116–204.5) | 0.008 |
| Cognitive impairment§ | |||
| 2 domains >1.5 SD below HC | 49% | 15% | <0.001 |
| 1 domain >2 SD below HC | 41% | 10% | <0.001 |
| 2 domains > 2 SD below HC | 19% | 0% | 0.001 |
| All 3 definitions pooled | 52% | 16% | <0.001 |
*Sociodemographic variables were compared between the SLE and control groups using Mann-Whitney, Χ2 and t-tests; cognitive test scores compared using one way analysis of variance.
†Premorbid IQ measured by Test of Premorbid Functioning scaled score.
‡Specific cognitive tests used for each domain are as follows: visual memory (Rey-Osterrieth Complex Figure Test recall score), verbal memory (California Verbal Learning Test trials 1–5), verbal fluency (Controlled Oral Word Association Test FAS sum), working memory (Letter Number Sequencing score), processing speed (Coding Score), complex attention (Trail Making Test B time in seconds (longer indicates worse performance)), psychomotor speed (Finger Tap Test dominant hand score).
§Impairment defined by number of cognitive domains either 1.5 or 2 SD below HC group mean, all three definitions pooled into fourth cognitive impairment category.
HC, healthy control; MoCA, Montreal Cognitive Assessment.