Table 2.
Association of pregnancy and lupus flares defined by PGAA: the Hopkins Lupus Cohort, 1987–2015 (n=1349).
| Flares | PY | Crude incidence per 100 PY | Crude IRR (95% CI) | Stratified CoxB HR (95% CI) |
|
|---|---|---|---|---|---|
| 12-Month Postpartum Period | |||||
| All patients (n=1349) | |||||
| Not pregnant/postpartum | 2246 | 5583.2 | 40.2 | 1.0 (ref) | 1.0 (ref) |
| Pregnancy | 134 | 220.8 | 60.7 | 1.51 (1.27, 1.80) | 1.59 (1.27, 1.96) |
| 12-months postpartum | 148 | 370.9 | 39.9 | 0.99 (0.84, 1.17) | 1.02 (0.83, 1.25) |
| Patients with ≥1 observed pregnancy in the cohort (n=304) | |||||
| Not pregnant/postpartum | 642 | 1790.4 | 35.9 | 1.0 (ref) | 1.0 (ref) |
| Pregnancy | 134 | 220.8 | 60.7 | 1.69 (1.40, 2.04) | 1.88 (1.48, 2.49) |
| 12-months postpartum | 148 | 370.9 | 39.9 | 1.11 (0.93, 1.33) | 1.24 (0.96, 1.66) |
| 3-Month Postpartum Period | |||||
| All patients (n=1349) | |||||
| Not pregnant/postpartum | 2336 | 5786.3 | 40.4 | 1.0 (ref) | 1.0 (ref) |
| Pregnancy | 134 | 220.8 | 60.7 | 1.50 (1.26, 1.79) | 1.57 (1.26, 1.92) |
| 3-months postpartum | 58 | 95.6 | 60.7 | 1.50 (1.16, 1.95) | 1.48 (1.07, 1.95) |
| Patients with ≥1 observed pregnancy in the cohort (n=304) | |||||
| Not pregnant/postpartum | 732 | 1993.5 | 36.7 | 1.0 (ref) | 1.0 (ref) |
| Pregnancy | 134 | 220.8 | 60.7 | 1.65 (1.38, 1.99) | 1.79 (1.40, 2.42) |
| 3-months postpartum | 58 | 95.6 | 60.7 | 1.65 (1.26, 2.16) | 1.71 (1.11, 2.52) |
A
Flare defined as change in ≥1 from PGA score at previous visit
B
Stratified Cox model is a conditional model that does not assume independence of multiple events of flares and allows different baseline hazards based on the number of previous flares a patient experienced
CI: confidence interval; HR: hazard ratio; IRR: incidence rate ratio; PGA: Physician Global Assessment of disease activity; PY: person-years; SLE: systemic lupus erythematosus