Table 3. Adjusted rates and rate differences for age-specific trajectories of respiratory health service utilization for birth groups.
| Age (in years) | Birth group | Adjusted Rate [95% CI] | Rate difference [95% CI] | Percentage of change (% [95% CI]) |
|---|---|---|---|---|
| Birth to < 1 | Reference | 370.7 [367.6, 373.8] | Reference | |
| Moderate/late PTB | 536.9 [524.1, 549.8] | 166.2 [147.3, 185.2]* | 45 [41, 47] | |
| Very PTB | 569.1 [537.1, 601.0] | 198.4 [152.4, 244.3]* | 54 [45, 61] | |
| SGA at term | 357.0 [347.9, 366.2] | -13.7 [-27.5, 0.1] | -4 [–6, 0] | |
| LGA at term | 433.1 [423.4, 442.7] | 62.4 [47.9, 76.9]* | 17 [14, 18] | |
| 1 to < 2 | Reference | 345.3 [342.3, 348.3] | Reference | |
| Moderate/late PTB | 454.0 [442.2, 465.8] | 108.7 [91.3, 126.2]* | 31 [29, 34] | |
| Very PTB | 590.6 [558.0, 623.1] | 245.3 [198.4, 292.2]* | 71 [63, 79] | |
| SGA at term | 325.8 [317.1, 334.6] | -19.5 [-32.7, -6.2]* | - 6 [–7, –4] | |
| LGA at term | 395.2 [386.0, 404.4] | 49.9 [36.0, 63.8]* | 14 [13, 16] | |
| 2 to < 3 | Reference | 228.5 [226.0, 230.9] | Reference | |
| Moderate/late PTB | 288.0 [278.6, 297.4] | 59.5 [45.7, 73.4]* | 26 [23, 29] | |
| Very PTB | 380.8 [355.0, 406.7] | 152.3 [115.2, 189.6]* | 67 [57, 76] | |
| SGA at term | 211.0 [204.0, 218.1] | -17.5 [-28.1, -6.8]* | - 8 [–10, –6] | |
| LGA at term | 251.9 [244.6, 259.3] | 23.4 [12.3, 34.5]* | 10 [8, 12] | |
| 3 to < 4 | Reference | 181.9 [179.8, 184.1] | Reference | |
| Moderate/late PTB | 235.4 [226.9, 243.9] | 53.5 [40.9, 66.0]* | 29 [26, 33] | |
| Very PTB | 247.9 [227.2, 268.6] | 66 [36.1, 95.8]* | 36 [26, 46] | |
| SGA at term | 168.9 [162.6, 175.2] | -13 [-22.6, -3.5]* | - 7 [–9, –5] | |
| LGA at term | 206.5 [199.9, 213.2] | 24.6 [14.6, 34.6]* | 14 [11, 16] | |
| 4 to < 5 | Reference | 147.9 [146.0, 149.9] | Reference | |
| Moderate/late PTB | 186.6 [179.0, 194.2] | 38.7 [27.4, 49.8]* | 26 [23, 29] | |
| Very PTB | 230.3 [210.4, 250.3] | 82.4 [53.7, 111.1]* | 56 [44, 67] | |
| SGA at term | 137.4 [131.7, 143.1] | -10.5 [-19.2, -2.0]* | - 7 [–10, –5] | |
| LGA at term | 158.2 [152.4, 164.1] | 10.3 [1.5, 19.1]* | 7 [4, 9] | |
| 5 to < 6 | Reference | 115.4 [113.7, 117.1] | Reference | |
| Moderate/late PTB | 143.3 [136.7, 149.9] | 27.9 [18.1, 37.7]* | 24 [20, 28] | |
| Very PTB | 157.5 [141.1, 173.9] | 42.1 [18.4, 65.8]* | 36 [24, 49] | |
| SGA at term | 111.1 [106.0, 116.2] | -4.3 [-12.0, 3.4] | -4 [–7, 3] | |
| LGA at term | 133.4 [128.0, 138.7] | 18 [9.9, 26.1]* | 16 [12, 19] |
Reference group = appropriate-for-gestational age infants born at term; CI = confidence interval; LGA = large for gestational age; PTB = preterm birth; SGA = small for gestational age.
Adjusted rates expressed as aggregated ED visits and hospitalizations for all combined respiratory conditions per 1,000 singleton live births.
* statistically significant differences (p-value < 0.05) between the corresponding adverse birth group and the reference group using Bonferroni’s correction of p-value for multiple comparisons.