Table 1. .
Characteristics of Hospital Admissions in Infants ≤60 Days Old That Were Linked To Confirmed Pertussis Cases With Maternal Vaccination Information Between 1 September 2014 and 31 March 2016 and From 1 September 2016 to 31 March 2018 in England
| All Cases | Pre-Policy Change | Post-Policy Change | |||||
|---|---|---|---|---|---|---|---|
| Characteristics | n | % (95% CI)a | n | % (95% CI)a | n | % (95% CI)a | Fisher’s Exact TestbP Value |
| Gender | |||||||
| Male | 88 | 43.8 (36.8–50.9) | 46 | 42.6 (33.1–52.5) | 42 | 45.2 (34.8–55.8) | .78 |
| Female | 113 | 56.2 (49.1–63.2) | 62 | 57.4 (47.5–66.9) | 51 | 54.8 (44.2–65.2) | |
| Admission week | |||||||
| ≤4 weeks | 44 | 21.9 (16.4–28.3) | 20 | 18.5 (11.7–27.1) | 24 | 25.8 (17.3–35.9) | .23 |
| ≥5 weeks | 157 | 78.1 (71.7–83.6) | 88 | 81.5 (72.9–88.3) | 69 | 74.2 (64.1–82.7) | |
| Gestational age at birth | |||||||
| Premature | 29 | 19.2 (13.3–26.4) | 20 | 25.0 (16.0–35.9) | 9 | 12.7 (6.0–22.7) | .06 |
| Full-term | 122 | 80.8 (73.6–86.7) | 60 | 75.0 (64.1–84.0) | 62 | 87.3 (77.3–94.0) | |
| Coinfections/clinical syndromes | |||||||
| Single infection | 115 | 57.2 (50.1–64.2) | 61 | 56.5 (46.6–66.0) | 54 | 58.1 (47.4–68.2) | .89 |
| Coinfection | 86 | 42.8 (35.8–49.9) | 47 | 43.5 (34.0–53.4) | 39 | 41.9 (31.8–52.6) | |
| Admitted to ICU | |||||||
| Admitted | 39 | 19.4 (14.2–25.6) | 24 | 22.2 (14.8–31.2) | 15 | 16.1 (9.3–25.2) | .29 |
| Not admitted | 162 | 28.6 (22.2–35.6) | 84 | 77.8 (68.8–85.2) | 78 | 83.9 (74.8–90.7) | |
| Ethnic group | .12 | ||||||
| White British | 135 | 71.4 (64.4–77.8) | 79 | 76.7 (41.7–84.5) | 56 | 65.1 (54.1–75.1) | |
| Other white ethnicity | 15 | 7.9 (4.5–12.8) | 5 | 4.9 (1.6– 11.0) | 10 | 11.6 (5.7–20.3) | |
| Other ethnicity | 39 | 20.6 (15.1–27.1) | 19 | 18.4 (11.5–27.3) | 20 | 23.3 (14.8–33.6) | |
| Mother immunized | |||||||
| Not immunized | 143 | 73.3 (66.5–79.4) | 74 | 71.2 (61.4–79.6) | 69 | 75.8 (65.7–84.2) | .52 |
| Immunized | 52 | 26.7 (20.6–33.5) | 30 | 28.8 (20.4–38.6) | 22 | 24.2 (15.8–34.3) | |
| Gestational age of mother when vaccinated | |||||||
| <28 weeks | 13 | 28.3 (16.0–43.5) | 1 | 3.7 (.9–19.0) | 12 | 63.2 (38.4–83.7) | <.001 |
| ≥28 weeks | 33 | 71.7 (56.5–84.0) | 26 | 96.3 (81.0–99.9) | 7 | 36.8 (16.3–61.6) | |
Abbreviations: CI, confidence interval; ICU, intensive care unit.
aDoes not include “not known.”
bFisher’s exact test comparing the program pre-policy change and post-policy change was used.