Table 4.
Risk for emergency department visits, follow-up outpatient visits, receipt of antibiotics, and receipt of antivirals among children with moderate-to-severe influenza at Kaiser Permanente Northern California, 2013–2014 influenza season.
| Healthcare utilizationb | Adjusted relative riska (95% CI) |
|||
|---|---|---|---|---|
| <6 months | ≥6 to <36 months | ≥3 to <9 years | ≥9 to <18 years | |
| Any emergency department visits | ||||
| Moderate-to-severe influenza | 1.3 (0.5–3.3) | 2.5* (1.4–4.5) | 2.6* (1.4–4.5) | 2.8* (1.8–4.3) |
| Female | 2.2 (0.9–5.1) | 1.4 (0.9–2.1) | 0.9 (0.5–1.5) | 0.8 (0.5–1.2) |
| Late PCR test | 0.6 (0.2–1.3) | 1.0 (0.7–1.6) | 1.2 (0.7–2.1) | 2.3* (1.4–3.8) |
| Comorbidities present | n/a | 1.4 (0.9–2.1) | 1.2 (0.7–2.0) | 1.3 (0.9–2.0) |
| Vaccinated in current season | n/a | 1.1 (0.7–1.7) | 1.2 (0.6–2.4) | 1.2 (0.7–2.2) |
| Vaccine primed | n/a | n/a | 0.7 (0.4–1.3) | 0.5 (0.3–1.0) |
| Any follow-up outpatient visits | ||||
| Moderate-to-severe influenza | – Not modeled – | 1.6* (1.2–2.2) | 2.3* (1.7–3.3) | 1.8* (1.3–2.6) |
| Female | 0.8 (0.7–1.1) | 1.1 (0.8–1.5) | 1.3 (0.9–1.8) | |
| Late PCR test | 0.95 (0.8–1.2) | 1.3 (0.9–1.8) | 1.1 (0.7–1.7) | |
| Comorbidities present | 1.3* (1.01–1.6) | 1.1 (0.8–1.5) | 1.7* (1.2–2.3) | |
| Vaccinated in current season | 1.2 (0.9–1.5) | 1.3 (0.9–1.9) | 1.2 (0.7–2.0) | |
| Vaccine primed | n/a | 0.9 (0.6–1.2) | 0.9 (0.6–1.4) | |
| Receipt of antibiotics | – Not modeled – | |||
| Moderate-to-severe influenza | 9.0* (4.1–19.8) | 5.6* (3.3–9.4) | 3.1* (1.9–4.9) | |
| Female | 1.1 (0.8–1.4) | 1.3 (0.9–1.9) | 1.0 (0.6–1.5) | |
| Late PCR test | 1.0 (0.7–1.3) | 0.8 (0.6–1.1) | 1.2 (0.8–1.8) | |
| Comorbidities present | 1.5* (1.1–1.9) | 1.1 (0.8–1.5) | 0.9 (0.6–1.4) | |
| Vaccinated in current season | 1.3* (1.01–1.7) | 1.3 (0.9–2.0) | 1.4 (0.7–2.6) | |
| Vaccine primed | n/a | 1.0 (0.7–1.4) | 0.8 (0.4–1.4) | |
| Receipt of antivirals | ||||
| Moderate-to-severe influenza | 0.7 (0.4–1.2) | 0.9 (0.7–1.3) | 0.9 (0.7–1.1) | 1.2 (0.99–1.5) |
| Female | 1.4 (0.8–2.5) | 0.9 (0.7–1.2) | 0.9 (0.7–1.2) | 1.0 (0.8–1.2) |
| Late PCR test | 1.1 (0.6–2.1) | 1.2 (0.9–1.6) | 1.1 (0.8–1.4) | 1.4* (1.1–1.7) |
| Comorbidities present | 0.9 (0.5–1.7) | 1.3 (0.95–1.7) | 1.3* (1.03–1.7) | 1.2 (0.95–1.4) |
| Vaccinated in current season | n/a | 1.1 (0.8–1.5) | 0.9 (0.6–1.3) | 1.0 (0.8–1.4) |
| Vaccine primed | n/a | n/a | 0.9 (0.7–1.2) | 1.1 (0.8–1.4) |
* Statistically significant at α = 0.05.
aModels were run for each individual outcome and by age group (i.e., no combined analyses of all ages).
bReference categories for each model: Mild influenza severity, male, early PCR test, early PCR test, no comorbidities present, not vaccinated in the current season, not vaccinated in prior season.
PCR: polymerase chain reaction.