Table 1.
Characteristics of the Study Population
| Baseline characteristics | ||
| No. of study subjects (n) | 219 | |
| Age (days): mean ± SD | 115.0 ± 124.1 | |
| Sex (%) | ||
| Female | 110 (50.2) | |
| Male | 109 (49.8) | |
| Weight on admission (g): mean ± SD | 5568 ± 2089 | |
| Ethnicitya (%) | ||
| African-American | 133 (60.7) | |
| Caucasian | 85 (38.8) | |
| Other | 1 (0.5) | |
| Birth weight (g): mean ± SD | 2956 ± 680 | |
| Gestational age at birth (weeks): mean ± SD | 38.0 ± 2.9 | |
| No. of persons living in homeb: mean ± SD | 4.8 ± 2.1 | |
| Day care attendancec (%) | 25.2 | |
| Breastfeedingd (%) | 39.7 | |
| Tobacco exposuree (%) | 30.1 | |
| Congenital anomaliesf (%) | 5.4 | |
| RSV disease descriptors | ||
| Duration of symptoms prior to enrollment (days) mean ± SD | 3.9 ± 2.2 | |
| Duration of symptoms prior to specimen collection (days)g mean ± SD | 4.7 ± 2.4 | |
| Requiring hospitalization (%) | 192 (87.7) | |
| Duration of hospitalizationh (days) mean ± SD | 6.6 ± 12.8 | |
| Duration of hospitalizationh (%) | ||
| <4 days | 102 (53.1) | |
| ≥4 days | 90 (46.9) | |
| Requiring intensive care (%) | 59 (26.9) | |
| Respiratory failurei (%) | 51 (23.3) | |
NOTE. SD, standard deviation.
Subject’s caregivers were asked to report the patient’s racial/ethnic classification as “African-American,” “Caucasian,” or “other.”
Excluding the study subject.
Present attendance, prior to illness, in a group care setting with at least 4 other children.
Any breastfeeding occurring for any duration after discharge from the birth hospitalization.
Any current use of a smoked form of tobacco by a person living with subject, regardless of whether or not such use occurred within the subject’s house.
Study subjects with congenital anomalies included 3 with gastroschesis, 2 with trisomy 21, and 1 subject each with hypospadia, isolated duodenal atresia, cystic kidney disease, congenital hydrocephalus, cerebral palsy, and Pierre-Robin syndrome. Subjects with hemodynamically significant congenital heart disease were excluded from study.
Calculated as the number of days between the onset of the earliest reported symptoms and specimen collection.
Of those subjects hospitalized.
Subjects who required mechanical ventilation at any time during the acute RSV illness except those intubated for apnea only. (The need for hospitalization, ICU admission and mechanical ventilation were decided upon by the treating physician and not influenced by the study or the investigators).