Table 4.
Subgroup analysis of incidence ratios for SLE flares resulting in hospitalization after influenza infection.
| Subgroup | Incidence ratio (95% CI) |
|---|---|
| Sex | |
| Women | 27.65 (18.38–41.62) |
| Men | 15.30 (5.23–44.76) |
| Age group | |
| < 20 | 25.50 (11.10–58.50) |
| 20–29 | 27.20 (11.92–62.07) |
| 30–39 | 23.54 (9.43–58.77) |
| 40–49 | 17.00 (5.98–48.35) |
| ≥ 50 | 37.84 (19.52–73.36) |
| Use of immunosuppressive agenta | |
| Yes | 24.29 (14.87–39.67) |
| No | 28.45 (15.76–51.33) |
| Use of corticosteroida | |
| Yes | 22.30 (14.77–33.67) |
| No | 59.50 (21.82–162.23) |
| Comorbidities | |
| CCI index 0 | 35.06 (18.41–66.76) |
| ≥ 1 | 20.04 (12.95–31.02) |
| Previous respiratory diseases during the 6 months prior to hospitalizationb | |
| Yes | 21.86 (9.59–49.84) |
| No | 26.82 (17.50–41.11) |
SLE systemic lupus erythematosus, CCI Charlson comorbidity index.
aImmunosuppressive agents or steroids which have been prescribed during 6 months before hospitalization.
bRespiratory disease codes were extracted from International Classification of Disease (ICD)-10 codes (I27.8, I27.9, J40.x-J47.x, J60.x-J67.x, J68.4, J70.1, J70.3) for Charlson comorbidity index analysis.