Table 3. Prevalence of major RSV risk factors in Ontario children less than 3 years.
| Risk Factor | Risk Factor Details | All | Hospitalized RSV N = 19,815 | Controls | p-value |
|---|---|---|---|---|---|
| N = 1,615,353 | N = 1,595,538 | ||||
| BPD | ICD-10 codes: ‘P27.1’ | 2482 (0.2%) | 187 (0.9%) | 2295 (0.1%) | <0.0001 |
| ICD 10 codes: ‘P27.1, P27.8, P27.9’ | 4094 (0.3%) | 273 (1.4%) | 3821 (0.2%) | <0.0001 | |
| Trisomy 21 | NA | 2072 (0.1%) | 145 (0.7%) | 1927 (0.1%) | <0.0001 |
| CHD | NA | 25,109 (1.6%) | 1,263 (6.4%) | 23,846 (1.5%) | <0.0001 |
| CHD + surgery | No. of surgeries | 3,821 | 245** | 3,576 | <0.0001 |
| No. of patients | 3,267 (0.2%) | 199 (1.0%) | 3,068 (0.2%) | <0.0001 | |
| Gestational age | Missing | 8,809 (0.5%) | 656 (3.3%) | 8,253 (0.5%) | <0.0001 |
| <33 weeks | 22,362 (1.4%) | 742 (3.7%) | 21,620 (1.4%) | <0.0001 | |
| 33–36 weeks | 103,042 (6.4%) | 2227 (11.2%) | 100,815 (6.3%) | <0.0001 | |
| >36 weeks | 1,481,040 (91.7%) | 16,190 (81.7%) | 1,464,850 (91.8%) | <0.0001 | |
| Patients without any of the four risk factors | CHD, *Prematurity, Trisomy 21, BPD | 1,465,803 (91.3%) | 15,482 (80.0%) | 1,450,321 (91.4%) | <0.0001 |
| CHD+Surgery, *Prematurity, Trisomy 21, BPD | 1,477,103 (92.0%) | 15,957 (83.3%) | 1,461,146 (92.1%) | <0.0001 | |
| Patients with at lease one of the four risk factors | CHD, *Prematurity, Trisomy 21, BPD | 140,641 (8.7%) | 3,677 (19.2%) | 136,964 (8.6%) | <0.0001 |
| CHD+Surgery, *Prematurity, Trisomy 21, BPD | 129,341 (8.0%) | 3,202 (16.7%) | 126,139 (7.9%) | <0.0001 |
Abbreviations: BPD = Bronchopulmonary Dysplasia; CHD = Congenital Heart Disease; RSV = Respiratory Syncytial Virus
** Surgeries before RSV = 119; Surgeries after RSV = 126.
* Prematurity defined as less than 37+0 weeks gestational age