Table 6. Association between mode of birth and hospital admission for LRTIs and URTIs in the MCS and SAIL cohorts.
| Hospital admission for | Hospital admission for | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Lower Respiratory Tract Infection | Upper Respiratory Tract Infection | ||||||||||||||
| MCS | SAIL | SAIL | |||||||||||||
| No. of events | Child-years | Rate per 100 child-years | Crude hazard ratio | Adjusted hazard ratio * | No. of events | Child-years | Rate per 100 child-years | Crude hazard ratio ** | Adjusted hazard ratio *** | No. of events | Child-years | Rate per 100 child-years | Crude hazard ratio ** | Adjusted hazard ratio **** | |
| (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | (95% CI) | ||||||||||
| P-value | P-value | P-value | P-value | P-value | P-value | ||||||||||
| n = 15,580 | n = 15,531 | n = 392,145 | n = 364,651 | n = 392,145 | n = 364,654 | ||||||||||
| Overall | 574 | 11,664 | 4.6 | 22,154 | 374,489 | 5.9 | 22,278 | 377,422 | 5.9 | ||||||
| VD | 420 | 8,308 | 4.6 | 1.00 | 1.00 | 14,697 | 239,134 | 6.2 | 1.00 | 1.00 | 14,073 | 241,384 | 5.8 | 1.00 | 1.00 |
| Assisted VD | 43 | 1,181 | 3.8 | 0.82 (0.57,1.19) | 1.18 (0.79, 1.75) | 2,024 | 44,348 | 4.6 | 0.73 (0.69, 0.76) | 0.97 (0.93, 1.02) | 2,495 | 44,425 | 5.6 | 0.95 (0.91, 0.99) | 1.03 (0.98, 1.07) |
| P = 0.301 | P = 0.420 | P<0.001 | P = 0.304 | P = 0.024 | P = 0.292 | ||||||||||
| Planned CS | 61 | 999 | 7.0 | 1.51 (1.13, 2.03) | 1.39 (1.03, 1.87) | 2,942 | 41,005 | 7.2 | 1.15 (1.11, 1.20) | 1.10 (1.05, 1.15) | 2,717 | 41,481 | 6.6 | 1.12 (1.07, 1.16) | 1.11 (1.06, 1.16) |
| P = 0.006 | P = 0.030 | P<0.001 | P<0.001 | P<0.001 | P<0.001 | ||||||||||
| Emergency CS | 50 | 1,176 | 3.7 | 0.83 (0.58, 1.20) | 1.14 (0.79, 1.65) | 2,491 | 50,002 | 5.0 | 0.80 (0.77, 0.84) | 1.03 (0.98, 1.08) | 2,993 | 50,132 | 6.0 | 1.02 (0.98, 1.06) | 1.09 (1.05, 1.14) |
| P = 0.328 | P = 0.494 | P<0.001 | P = 0.244 | P = 0.326 | P<0.001 | ||||||||||
* Adjusted for maternal age, firstborn, infant’s sex, maternal smoking, gestational age and breastfeeding per month of follow-up
** Adjusted for year of birth
***Adjusted for maternal age, area deprivation quintile, firstborn, smoking, maternal asthma, hypertensive conditions, infant’s sex, ethnicity, gestational age, birthweight, breastfeeding, season and year of birth
**** Adjusted for maternal age, area deprivation quintile, firstborn, smoking, maternal asthma, infant’s sex, ethnicity, gestational age, birthweight, breastfeeding, season and year of birth