Table 1.
Characteristics of Pregnant Women With 1 or More Respiratory Illness Episode: PRIME Cohort Study, 2017–2018
| Overall (N = 3965) | Influenza Positive (n = 309) | ||||
|---|---|---|---|---|---|
| n | (Col %) | n | (Row %) | Relative Risk | |
| Study year | |||||
| 2017 (year 1) | 1641 | (41.4) | 141 | (8.6) | Ref |
| 2018 (year 2) | 2324 | (58.6) | 168 | (7.2) | 0.84 |
| Site | |||||
| India | 1585 | (40.0) | 115 | (7.3) | Ref |
| Peru | 1874 | (47.3) | 109 | (5.8) | 0.80 |
| Thailand | 506 | (12.8) | 85 | (16.8) | 2.32 |
| Age, mean (SD), years | 27.3 (5.7) | 28.2 (6.0) | |||
| Educationa | |||||
| No formal education | 39 | (1.0) | 3 | (7.7) | Ref |
| Primary | 526 | (13.3) | 48 | (9.1) | 1.19 |
| Secondary | 2060 | (52.0) | 138 | (6.7) | 0.87 |
| Postsecondary/university | 1336 | (33.7) | 119 | (8.9) | 1.16 |
| ≥1 underlying medical conditionb | 667 | (16.8) | 49 | (7.3) | 0.93 |
| Respiratory conditions | 96 | (2.4) | 3 | (3.1) | 0.40 |
| Current smoker | 141 | (3.6) | 9 | (6.4) | 0.81 |
| Vaccinated against influenzac | 1000 | (25.2) | 49 | (4.9) | 0.56 |
| Parity, mean (SD)a | 1.1 (1.2) | 1.2 (1.2) | |||
| GA at enrollment, mean (SD), weeks | 17.6 (6.1) | 17.5 (6.1) | |||
| Number of ILS episodes with respiratory specimen collection | |||||
| 1 | 2883 | (72.7) | 202 | (7.0) | Ref |
| 2 | 793 | (20.0) | 68 | (8.6) | 1.22 |
| 3 | 209 | (5.3) | 26 | (12.4) | 1.78 |
| >3 | 80 | (2.0) | 13 | (16.3) | 2.32 |
| Days from symptom onset to respiratory specimen collection, mean (SD)d | 2.6 (1.7) | 2.2 (1.5) | |||
N = 3965 pregnant women.
Abbreviations: Col, column; GA, gestational age; ILS, influenza-like symptom; PRIME, Pregnancy and Influenza Multinational Epidemiologic; Ref, reference.
a
Five missing responses.
b
During the prior 24 months.
c
Vaccinated against influenza at least 14 days prior to report of symptom onset as verified by vaccination or medical records.
d
Unit of analysis is illness episodes.