Characterisation of patients with systemic lupus erythematosus and matched subjects from the general population
| Characteristic | Matched general population, N=5365 | Patients with SLE, N=1073 | SMD | 95% CI | P value |
| Age, 31 December 2020 (SD) | 50.44 (15.30) | 50.67 (14.89) | −0.02 | −0.08 to 0.05 | 0.7 |
| Gender, female | 4710 (87.8) | 942 (87.8) | 0 | −0.07 to 0.07 | >0.9 |
| Socioeconomic status | 0 | −0.07 to 0.07 | >0.9 | ||
| Low | 880 (16.4) | 176 (16.4) | |||
| Medium | 2685 (50.0) | 537 (50.0) | |||
| High | 1800 (33.6) | 360 (33.6) | |||
| Smoking, ever | 742 (13.8) | 136 (12.7) | 0.03 | −0.03 to 0.10 | 0.3 |
| BMI, last | 0.23 | 0.16 to 0.29 | <0.001 | ||
| Underweight | 174 (3.2) | 33 (3.1) | |||
| Normal | 2205 (41.1) | 486 (45.3) | |||
| Overweight | 1628 (30.3) | 295 (27.5) | |||
| Obese | 1228 (22.9) | 258 (24.0) | |||
| Missing | 130 (2.4) | 1 (0.1) | |||
| CCI | 0.77 (1.50) | 2.28 (1.83) | −0.9 | −1.0 to 0.84 | <0.001 |
| Comorbidities | |||||
| MI | 68 (1.3) | 28 (2.6) | −0.1 | −0.16 to 0.03 | <0.001 |
| IHD | 155 (2.9) | 68 (6.3) | −0.16 | −0.23 to 0.10 | <0.001 |
| CHF | 25 (0.5) | 17 (1.6) | −0.11 | −0.18 to 0.05 | <0.001 |
| AF | 75 (1.4) | 23 (2.1) | −0.06 | −0.12 to 0.01 | 0.069 |
| PVD | 39 (0.7) | 17 (1.6) | −0.08 | −0.15 to 0.01 | 0.006 |
| Cardiovascular disease | 407 (7.6) | 193 (18.0) | −0.32 | −0.38 to 0.25 | <0.001 |
| CVA/TIA | 66 (1.2) | 32 (3.0) | −0.12 | −0.19 to 0.06 | <0.001 |
| Pulmonary embolism | 40 (0.7) | 63 (5.9) | −0.29 | −0.36 to 0.22 | <0.001 |
| Arterial embolism | 5 (0.1) | 11 (1.0) | −0.13 | −0.19 to 0.06 | <0.001 |
| Deep vein thrombosis | 223 (4.2) | 174 (16.2) | −0.41 | −0.47 to 0.34 | <0.001 |
| Any thromboembolic event | 307 (5.7) | 234 (21.8) | −0.48 | −0.55 to 0.41 | <0.001 |
| Hypertension | 1175 (21.9) | 318 (29.6) | −0.18 | −0.24 to 0.11 | <0.001 |
| Diabetes | 468 (8.7) | 82 (7.6) | 0.04 | −0.03 to 0.10 | 0.2 |
| Osteoporosis | 599 (11.2) | 320 (29.8) | −0.48 | −0.54 to 0.41 | <0.001 |
| CKD | 631 (11.8) | 394 (36.7) | −0.61 | −0.68 to 0.54 | <0.001 |
| HCRU 2020 | |||||
| Visits to PCP and paediatrician | 8.95 (7.68) | 15.65 (9.80) | −0.76 | −0.83 to 0.69 | <0.001 |
| Visits to specialists | 1.36 (6.47) | 2.94 (10.31) | −0.18 | −0.25 to 0.12 | <0.001 |
| Hospitalisation, at least one | 423 (7.9) | 159 (14.8) | 0.22 | 0.15 to 0.29 | <0.001 |
| Hospitalisation days, among those hospitalised | 12.22 (41.75) | 10.50 (25.27) | 0.05 | −0.13 to 0.23 | 0.054 |
Continuous variables are presented as mean (SD), categorical variables are presented as number (%). P values are results of Wilcoxon rank sum test, Pearson’s χ² test, Fisher’s exact test, as appropriate.
AF, atrial fibrillation; BMI, body mass index; CCI, Charlson’s Comorbidity Index; CHF, congestive heart failure; CKD, chronic kidney disease; CVA/TIA, cerebrovascular accident/transient ischaemic attack; HCRU, healthcare resource utilisation; IHD, ischaemic heart disease; MI, myocardial infarction; PCP, primary care physician; PVD, peripheral vascular disease; SLE, systemic lupus erythematosus; SMD, standardised mean difference.