Table 2.
Unadjusted and adjusted logistic regression models for the likelihood of SARS-CoV-2 test-positivity compared to non-positive (negative and not tested) and test-negative pregnant women in Norway, in relation to characteristics.
| Characteristics | Test-positive n = 929¤ |
Non-positive n = 80,658 |
Test-negative n = 29,699 |
Test-positive vs. non-positive | Test-positive vs. test-negative | ||
|---|---|---|---|---|---|---|---|
| Unadjusted model | Adjusted for age, birth region and education* | Unadjusted model | Adjusted for age, birth region and education* | ||||
| n (%) | n (%) | n (%) | OR (95%CI) | OR (95%CI) | OR (95%CI) | OR (95%CI) | |
| Background | |||||||
| Age (years) | |||||||
| < 25 | 71 (7.6) | 6362 (7.9) | 1948 (6.6) | 0.94 (0.73–1.22) | 0.76 (0.58–0.99) | 1.20 (0.92–1.55) | 0.82 (0.63–1.08) |
| 25–29 | 277 (29.8) | 24,407 (30.3) | 8628 (29.1) | 0.96 (0.82–1.12) | 0.93 (0.80–1.09) | 1.06 (0.90–1.23) | 0.98 (0.83–1.15) |
| 30–34 | 378 (40.7) | 31,980 (39.7) | 12,430 (41.9) | Reference | Reference | Reference | Reference |
| ≥ 35 | 203 (21.9) | 17,909 (22.2) | 6693 (22.5) | 0.96 (0.81–1.14) | 0.86 (0.72–1.02) | 1.00 (0.84–1.19) | 0.85 (0.72–1.02) |
| Parity | |||||||
| 0 | 329 (35.4) | 34,081 (42.3) | 11,407 (38.4) | Reference | Reference | Reference | Reference |
| 1 | 340 (36.6) | 30,690 (38.1) | 12,597 (42.4) | 1.15 (0.99–1.33) | 1.13 (0.96–1.32) | 0.94 (0.80–1.09) | 0.97 (0.83–1.14) |
| 2 | 166 (17.3) | 11,548 (14.3) | 4347 (14.6) | 1.44 (1.19–1.75) | 1.27 (1.04–1.55) | 1.28 (1.06–1.56) | 1.16 (0.95–1.43) |
| ≥ 3 | 99 (10.7) | 4339 (5.4) | 1348 (4.5) | 2.36 (1.88–2.97) | 1.46 (1.13–1.88) | 2.54 (2.01–3.21) | 1.43 (1.10–1.88) |
| BMI | |||||||
| < 18.5 | 23 (2.7) | 2448 (3.3) | 811 (2.9) | 0.87 (0.57–1.32) | 0.72 (0.47–1.10) | 0.98 (0.64–1.49) | 0.76 (0.49–1.17) |
| 18.5–< 25 | 472 (55.3) | 43,848 (58.6) | 16,256 (58.9) | Reference | Reference | Reference | Reference |
| 25–< 30 | 232 (27.2) | 17,800 (23.8) | 6543 (23.7) | 1.21 (1.03–1.42) | 1.12 (0.95–1.31) | 1.22 (1.04–1.43) | 1.09 (0.93–1.29) |
| 30–< 35 | 90 (10.5) | 7145 (9.6) | 2629 (9.5) | 1.17 (0.93–1.47) | 1.09 (0.86–1.37) | 1.18 (0.94–1.48) | 1.03 (0.61–1.22) |
| ≥ 35 | 37 (4.3) | 3557 (4.8) | 1343 (4.9) | 0.97 (0.69–1.35) | 0.95 (0.68–1.34) | 0.95 (0.68–1.33) | 0.86 (0.83–1.38) |
| Missing | 75 | 5860 | 2117 | ||||
| Educational level (years) | |||||||
| ≤ 9 | 188 (24.6) | 10,580 (14.4) | 3217 (11.5) | 2.12 (1.78–2.53) | 1.41 (1.16–1.71) | 2.86 (2.39–3.42) | 1.73 (1.42–2.12) |
| 10–12 | 179 (23.4) | 15,612 (21.1) | 5243 (18.7) | 1.37 (1.15–1.63) | 1.29 (1.08–1.54) | 1.67 (1.40–2.00) | 1.52 (1.27–1.83) |
| > 12) | 398 (52.0) | 47,494 (64.4) | 19,505 (69.7) | Reference | Reference | Reference | Reference |
| Missing | 164 | 6972 | 1734 | ||||
| Birth region | |||||||
| Scandinavia# | 461 (49.7) | 60,185 (74.7) | 23,867 (81.4) | Reference | Reference | Reference | Reference |
| Other European c ountry | 153 (16.5) | 8883 (12.1) | 2506 (8.4) | 2.25 (1.87–2.70) | 2.13 (1.75–2.60) | 3.16 (2.62–3.81) | 2.75 (2.25–3.36) |
| Middle East/Africa | 224 (24.1) | 5454 (6.8) | 1450 (4.9) | 5.36 (4.56–6.30) | 4.66 (2.86–5.63) | 8.00 (6.76–9.47) | 5.95 (4.90–7.23) |
| Other | 90 (9.8) | 6047 (7.5) | 1867 (6.3) | 1.94 (1.55–2.44) | 1.83 (1.45–2.32) | 2.52 (2.01–3.18) | 2.22 (1.75–2.82) |
| Missing | 1 | 89 | 0 | ||||
| Smoking status | |||||||
| Smoker, yes | 52 (6.3) | 4175 (5.8) | 1352 (5.1) | 1.10 (0.83–1.46) | 1.01 (0.76–1.35) | 1.26 (0.95–1.68) | 1.00 (0.74–1.34) |
| Missing | 106 | 8205 | 3090 | ||||
| Work situation | |||||||
| Employed | 527 (72.6) | 58,156 (84.1) | 22,378 (87.2) | Reference | Reference | Reference | Reference |
| Unemployed | 199 (27.4) | 10,999 (15.9) | 3274 (12.8) | 2.00 (1.69–2.35) | 1.16 (0.96–1.40) | 2.58 (2.18–3.05) | 1.30 (1.08–1.58) |
| Missing | 203 | 11,503 | 4047 | ||||
| Co-habits with partner | |||||||
| No | 52 (5.7) | 3213 (4.0) | 1068 (3.7) | 1.44 (1.09–1.91) | 0.96 (0.72–1.28) | 1.60 (1.20–2.13) | 0.88 (0.65–1.19) |
| Missing | 21 | 1234 | 490 | ||||
| Pre-existing co-morbidities | |||||||
| Chronic hypertension | 3 (0.3) | 462 (0.6) | 184 (0.6) | 0.56 (0.18–1.75) | 0.53 (0.17–1.66) | 0.52 (0.17–1.63) | 0.44 (0.14–1.40) |
| Diabetes | 8 (0.9) | 572 (0.7) | 215 (0.7) | 1.22 (0.60–2.45) | 1.35 (0.62–2.54) | 1.19 (0.59–2.42) | 1.09 (0.53–2.26) |
| Lung disease/asthma | 52 (5.6) | 5142 (6.4) | 2048 (6.9) | 0.87 (0.66–1.15) | 0.86 (0.51–1.46) | 0.80 (0.60–1.06) | 0.98 (0.73–1.30) |
| Chronic kidney disease | 1 (0.1) | 472 (0.6) | 178 (0.6) | – | – | – | – |
| Cardiovascular disease | 0 (–) | 461 (0.6) | 173 (0.6) | – | – | – | – |
| Prior thrombosis | 0 (–) | 166 (0.2) | 56 (0.2) | – | – | – | – |
| Composite of the above | 61 (6.6) | 6982 (8.7) | 2738 (9.2) | 0.74 (0.57–0.96) | 0.87 (0.67–1.14) | 0.69 (0.53–0.90) | 0.80 (0.62–1.05) |
| Pregnancy related factors | |||||||
| Multiple pregnancy | 12 (1.3) | 1071 (1.3) | 427 (1.4) | 0.97 (0.55–1.72) | 0.97 (0.55–1.72) | 0.90 (0.50–1.60) | 0.88 (0.49–1.58) |
| Pre-eclampsia, HELLP and eclampsia | 13 (1.4) | 2215 (2.8) | 842 (2.8) | 0.50 (0.29–0.87) | 0.54 (0.31–0.93) | 0.49 (0.28–0.84) | 0.50 (0.29–0.88) |
| Gestational diabetes | 77 (8.3) | 4758 (5.9) | 1731 (5.8) | 1.44 (1.14–1.82) | 1.13 (0.89–1.43) | 1.46 (1.15–1.85) | 1.09 (0.85–1.39) |
| In vitro fertilization (IVF) | 28 (3.0) | 3819 (4.7) | 1329 (4.5) | 0.63 (0.43–0.91) | 0.72 (0.49–1.06) | 0.66 (0.45–0.97) | 0.80 (0.54–1.17) |
¤8 of 929 (0.9%) positive women had been vaccinated during the study period. *For the association between age and tested, the adjusted model included the covariate education and birth region. For the association between education and tested, the adjusted model included the covariates age and birth region. For the association between birth region and tested, the adjusted model included the covariates age and education. #Sweden, Norway, Denmark.