Table 4.
Associations of baseline demographic- and treatment-related factors with COVID-19 breakthrough after tixagevimab/cilgavimab receipt
| Variable | COVID-19 cases | Personmonths | Incidence rate (per 1000 person-months) | Multivariable HRa (95% CI) |
|---|---|---|---|---|
| Age (per 10 years) | 83 | 2,637.6 | 31.5 (24.7, 38.2) | 0.86 (0.75 – 0.99) |
| Sex | ||||
| Female | 62 | 2,047.9 | 30.3 (22.7, 37.8) | 1.00 (ref) |
| Male | 21 | 589.7 | 35.6 (20.4, 50.9) | 1.13 (0.67 – 1.90) |
| Calendar time | ||||
| Before 4/6/2022 | 48 | 1,394.2 | 34.4 (24.7, 44.2) | 1.00 (ref) |
| 4/6 to 6/30/2022 | 21 | 841.5 | 26.1 (15.2, 37.1) | 1.01 (0.54 – 1.87) |
| 7/1/2022 and later | 13 | 401.9 | 32.3 (14.8, 49.9) | 1.62 (0.80 – 3.27) |
| Spike antibody level | ||||
| <0.4 | 36 | 1,089 | 33.1 (22.3, 43.9) | 1.00 (ref) |
| 0.4 to 200 | 14 | 405.4 | 34.5 (16.4, 52.6) | 0.94 (0.45 – 1.96) |
| >200 | 9 | 551.6 | 16.32 (5.7, 27.0) | 0.42 (0.18 – 0.99) |
| Missing | 24 | 591.6 | 40.6 (24.3, 56.8) | 0.93 (0.40 – 2.17) |
| Previous COVID-19 before index date | ||||
| No | 72 | 2,167.2 | 33.2 (25.6, 40.9) | 1.00 (ref) |
| Yes | 11 | 470.4 | 23.4 (9.6, 37.2) | 0.66 (0.35 – 1.25) |
| DMARD use | ||||
| csDMARD onlyb | 8 | 321.0 | 24.9 (7.7, 42.2) | 1.00 (ref) |
| No DMARD | 2 | 58.3 | 34.3 (0.0, 81.9) | 1.55 (0.31 – 7.72) |
| MMF | 13 | 354.6 | 36.7 (16.7, 56.6) | 1.45 (0.59 – 3.60) |
| CD20 inhibitor | 42 | 1,460.5 | 28.8 (20.1, 37.5) | 1.05 (0.44 – 2.49) |
| Other b/tsDMARD | 18 | 443.1 | 40.6 (21.9, 59.4) | 1.89 (0.83 – 4.32) |
COVID-19, coronavirus disease 2019; HR, hazard ratio; CI, confidence interval; conventional synthetic disease-modifying antirheumatic drug; MMF, mycophenolate mofetil; b/tsDMARD, biologic and targeted synthetic disease-modifying antirheumatic drug; MMF, mycophenolate mofetil
a
Adjusted for age and sex, calendar date, spike antibody level, DMARD use, previous COVID-19
b
csDMARD other than MMF