Table 3 Multivariable logistic regression analyses of the association between premature delivery and clinical course and treatment of pertussis; crude and adjusted OR and 95% confidence intervals (95%CI)
From: Pertussis hospitalizations among term and preterm infants: clinical course and vaccine effectiveness
|  | Probable and certain term infants (n = 596)a,b | Preterm infants (n = 80)b | Crude OR (95% CI) | Adjusted OR (95% CI)c |
|---|---|---|---|---|
Symptoms at admission | ||||
 Coughing attacks | 438 (73.5%) | 56 (70.0%) | 0.8 (0.5–1.4) | 0.8 (0.5–1.4) |
 Apnea | 92 (15.4%) | 18 (22.5%) | 1.6 (0.9–2.8) | 1.8 (1.0–3.3) |
 Whooping | 23 (3.9%) | 1 (1.3%) | 0.3 (0.04–2.4) | 0.3 (0.04–2.3) |
 Vomiting | 210 (35.2%) | 28 (35.0%) | 1.0 (0.6–1.6) | 1.0 (0.6–1.6) |
 Prolonged inspiratory effort | 42 (7.1%) | 7 (8.8%) | 1.3 (0.5–2.9) | 1.2 (0.5–2.7) |
 Collapse | 6 (1.0%) | 2 (2.5%) | 2.5 (0.5–12.7) | 3.8 (0.7–19.7) |
 Cyanosis | 259 (43.5%) | 25 (31.3%) | 0.6 (0.4–1.0) | 0.7 (0.4–1.1) |
 Fever | 52 (8.7%) | 8 (10.0%) | 1.2 (0.5–2.6) | 0.9 (0.4–2.0) |
 Feeding problems | 185 (31.0%) | 27 (33.8%) | 1.1 (0.7–1.9) | 1.1 (0.7–1.9) |
Complications | ||||
 Any complication | 53 (8.9%) | 10 (12.5%) | 1.5 (0.7–3.0) | 1.6 (0.8–3.4) |
Treatment | ||||
 Antibiotics before admission | 114/580 (19.7%) | 18/77 (23.4%) | 1.1 (0.6–2.0) | 1.1 (0.6–1.9) |
 Antibiotics during admission | 475/587 (80.9%) | 68/78 (87.2%) | 1.5 (0.7–3.2) | 1.8 (0.9–3.9) |
 Artificial respiration | 39/577 (6.8%) | 11/77 (14.3%) | 2.3 (1.1–4.8) | 2.8 (1.3–6.0) |
 Additional oxygen | 198/585 (33.9%) | 28 (36.8%) | 1.1 (0.7–1.9) | 1.3 (0.8–2.2) |
 Admission intensive care unit (ICU) | 59 (9.9%) | 10 (12.5%) | 1.3 (0.6–2.7) | 1.6 (0.8–3.6) |
Discharge | ||||
 Symptoms remaining | 460 (77.2%) | 58 (72.5%) | 0.8 (0.5–1.3) | 0.8 (0.5–1.4) |