Alternative multivariate analysis of cognitive impairment in patients with RA (including IL-6 instead of average CRP)
| Variable | Univariate OR (95%CI) | Multivariate OR* (95%CI) | P value |
| Age, years | 1.045 (1.001 to 1.090) | ||
| Female sex | 1.364 (0.405 to 4.590) | ||
| Educational level* | 0.335 (0.156 to 0.721) | 0.173 (0.060 to 0.499) | 0.001 |
| Obesity (BMI≥30) | 3.692 (1.081 to 12.060) | 7.482 (1.297 to 23.176) | 0.024 |
| Arterial hypertension | 3.000 (0.870 to 10.343) | ||
| Dyslipidaemia | 3.630 (0.954 to 14.622) | ||
| Depression (HADS) | 1.129 (0.952 to 1.340) | ||
| Average DAS28 | 2.022 (1.079 to 3.787) | 2.372 (1.046 to 5.376) | 0.039 |
| IL-6, pg/mL | 1.025 (1.002 to 1.062) | 1.079 (1.005 to 1.159) | 0.036 |
Nagelkerke R2 = 0.455. The variables included in the equation were age, sex, cultural level, obesity, average DAS28 and IL-6.
*Educational level: secondary education or university compared with primary education.
BMI, body mass index; CRP, C-reactive protein; DAS28, 28-joint Disease Activity Score; HADS, Hospital Anxiety and Depression Scale; IL-6, interleukin 6; RA, rheumatoid arthritis.