Morbidities of prematurity by treatment group
| Morbidity | Azithromycin (n=60) | Placebo (n=61) | P value* |
| N (%) acquired prior to discharge | N (%) acquired prior to discharge | ||
| Pneumothorax | 7/55 (13) | 4/57 (7) | 0.49 |
| PDA | 25/55 (45) | 21/56 (38) | 0.33 |
| Feeding intolerance | 20/51 (39) | 34/58 (59) | 0.04 |
| Gastro-oesophageal reflux | 14/60 (23) | 11/61 (18) | 0.54 |
| Intestinal perforation | 2/60 (3) | 4/61 (7) | 0.68 |
| NEC ≥stage 2 | 4/60 (7) | 5/61 (8) | >0.99 |
| Culture-confirmed sepsis | 8/60 (13) | 14/61 (23) | 0.18 |
| IVH† | 0.33 | ||
| None | 31/53 (58) | 40/54 (74) | |
| Grade 1 | 10/53 (19) | 7/54 (13) | |
| Grade 2 | 5/53 (9) | 5/54 (9) | |
| Grade 3 | 5/53 (9) | 1/54 (2) | |
| Grade 4 | 2/53 (4) | 1/54 (2) | |
| Shunted PHH | 6/60 (10)‡ | 0/61 (0) | 0.01 |
| PVL | 4/60 (7) | 5/61 (8) | >0.99 |
| ROP (highest stage)§ | 0.28 | ||
| None | 18/56 (32) | 25/56 (45) | |
| Stage 1 | 17/56 (30) | 17/56 (30) | |
| Stage 2 | 10/56 (18) | 10/56 (18) | |
| Stage 3 | 11/56 (20) | 3/56 (5) | |
| Stage 4 | 0/56 (0) | 1/56 (2) |
*P values for binary outcomes are based on a score test from generalised estimating equations to account for correlations between twins, or Fisher’s exact test when one of the cell sizes has an expectation of less than 5.
†The IVH proportions exclude 12 participants who had IVH prior to their first dose and who did not progress. It also excludes two who never received the treatment to which they were randomised.
‡For azithromycin-assigned participants with shunted PHH, IVH status at baseline was unknown in four participants; grade 2 in one participant; and one infant was never dosed.
§Four assigned to azithromycin and five assigned to placebo were never assessed for ROP and are not included.
IVH, intraventricular haemorrhage; NEC, necrotising enterocolitis; PDA, patent ductus arteriosus; PHH, posthaemorrhagic hydrocephalus; PVL, periventricular leukomalacia; ROP, retinopathy of prematurity.