Table 2.
Demographic characteristics and univariable odds ratios (ORs) with 95% confidence intervals (CIs) for the association between selected variables and risk of lupus
| Study subjects (%) | ||||
|---|---|---|---|---|
| Case (n = 875) | Control (n = 3632) | OR* (95% CI) | ||
| Sex† | Female | 721 (82.4%) | 3012 (82.9%) | |
| Age at diagnosis (years)† | Age (SD) | 45.4 (15.1) | 45.3 (15.1) | |
| Range | 4.5–85.5 | 4.5–88.4 | ||
| Time in database (years)‡ | 1–3 | 209 (23.9) | 1112 (30.6) | 1.00 (reference) |
| 3–4.5 | 165 (18.9) | 770 (21.2) | 1.37 (1.03, 1.83) | |
| 4.5–7 | 246 (28.1) | 950 (26.2) | 2.43 (1.79, 3.30) | |
| >7 | 255 (29.1) | 800 (22.0) | 4.27 (3.03, 6.02) | |
| P < 0.001 | ||||
| Consultation rate§ | 0–6 | 55 (6.29) | 1060 (29.19) | 1.00 (reference) |
| 7–12 | 105 (12.00) | 672 (18.50) | 4.27 (2.95, 6.18) | |
| 13–24 | 194 (22.17) | 826 (22.74) | 8.51 (5.95, 12.2) | |
| >24 | 521 (59.54) | 1074 (29.57) | 28.2 (19.4, 40.8) | |
| P < 0.001 | ||||
*
Univariable odds ratio for risk of lupus.
†
Variable used to match cases and controls, therefore univariable OR is not reported.
‡
Time (in years) in database before diagnosis.
§
Number of consultations per year in the year preceding diagnosis date (index date for the controls).