McGill University Health Centre SLE patients with retinal toxicity (cases) versus matched SLE controls without retinal toxicitya.
| Variable | Cases, n = 18 | Controlsb, n = 54 | 95% CI for Difference |
|---|---|---|---|
| Females, n (%) | 16 (88.9) | 50 (92.6) | −10.9 to 29.2f |
| White, n (%) | 11 (61.1) | 40 (74.1) | −12.0 to 40.1f |
| Abnormal GFR or endstage renal disease, n (%) | 4 (22.2) | 8 (14.8) | −12.2 to 34.4f |
| Mean daily dose > 5 mg/kg HCQ or > 2.3 mg/kg CQc, n (%) | 12 (66.7) | 26 (48.2) | −10.5 to 41.9f |
| Ever exposed to > 5 mg/kg HCQ or > 2.3 mg/kg CQ, n (%) | 17 (94.4) | 44 (81.5) | −12.4 to 27.3f |
| Ever exposed to > 6.5 mg/kg HCQ or > 3 mg/kg CQ, n (%) | 11 (61.1) | 24 (44.4) | −12.0 to 41.2f |
| Missing ≥ 1 ophthalmology assessment, n (%)d | 9 (50.0) | 35 (64.8) | –12.4 to 41.0f |
| Median age at SLE diagnosis (IQR)e | 29 (23–35) | 29 (24–38) | −4.2 to 6.7g |
| Median HCQ/CQ use, yrs (IQR)e | 19 (14–20) | 16 (11–22) | −6.0 to 2.0g |
↵a Based on the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index recorded at yearly SLE assessments.
↵b Controls were matched 3:1 on age at SLE diagnosis (within 5 yrs), and SLE duration.
↵c Daily dose of antimalarial agents per actual body weight averaged for the entire course of treatment.
↵d Adherence to annual ophthalmology assessments recorded over the last 5 years preceding discontinuation of antimalarial therapy for patients with retinal toxicity (cases) and recorded over the last 5 years of antimalarial therapy for patients without retinal complications (controls).
↵e IQR: interquartile range.
↵f 95% CI for difference in percentage.
↵g 95% CI for difference in mean. SLE: systemic lupus erythematosus; GFR: glomerular filtration rate; HCQ: hydroxychloroquine; CQ: chloroquine.