Table 1. Baseline Characteristics of the Study Participantsa.
| Characteristic | Study group | |
|---|---|---|
| Streptococcus salivarius K12 intervention (n = 413) | Placebo (n = 414) | |
| Age, mean (SD), y | 4.1 (1.6) | 4.1 (1.6) |
| Sex | ||
| Female | 194 (47.0) | 200 (48.3) |
| Male | 219 (53.0) | 214 (51.7) |
| Cystic fibrosis | 0 | 0 |
| Primary ciliary disease | 0 | 0 |
| 10-Valent PCV vaccinationb | 368 (96.8) | 375 (96.6) |
| Influenza vaccinationc | 123 (45.6) | 133 (48.7) |
| Any allergyb | 53 (13.9) | 71 (18.3) |
| Underlying illness requiring ongoing medicationb | 15 (3.9) | 21 (5.4) |
| Current use of other probiotic productsb,d | 59 (15.5) | 59 (15.2) |
| Any antimicrobial therapy during the preceding 6 mo before study entryb | 43 (11.3) | 47 (12.1) |
| Risk factors for AOMb | ||
| No. of siblings | ||
| 0 | 68 (17.9) | 64 (16.5) |
| 1 | 170 (44.7) | 183 (47.2) |
| ≥2 | 142 (37.4) | 141 (36.3) |
| Parental smoking | 77 (20.3) | 68 (17.5) |
| Current pacifier use | 20 (5.3) | 22 (5.7) |
| Former pacifier use | 262 (68.9) | 277 (71.4) |
| Duration of breastfeeding, mean (SD), mo | 5.0 (4.0) | 5.2 (4.6) |
| AOM-related surgeryb | ||
| Tympanostomy | 64 (16.8) | 57 (14.7) |
| Presence of tympanostomy tubes | 22 (5.8) | 23 (5.9) |
| Adenoidectomy | 24 (6.3) | 25 (6.4) |
Abbreviations: AOM, acute otitis media; PCV, pneumococcal conjugate vaccine.
a
Unless otherwise indicated, data are expressed as No. (%) of 413 in the S salivarius K12 and 414 children in the placebo group.
b
Data are available from 380 children in the Streptococcus salivarius K12 group and 388 in the placebo group.
c
Data are available from 270 children in the Streptococcus salivarius K12 group and 273 in the placebo group.
d
Includes Lactobacilli or Saccharomyces species.