Models | Difference in MgSO4 uptake (percentage points)* | 95% CI (percentage points) | P value | |
1 | Unadjusted† | 12.2 | 9.5 to 15.0 | <0.001 |
2 | Adjusted for unit size‡ | 11.0 | 8.9 to 13.1 | <0.001 |
3 | Adjusted for unit size and clustering by AHSN§ | 11.0 | 8.4 to 13.5 | <0.001 |
4 | Adjusted for unit size, clustering by AHSN and NPP month¶ | 6.7 | 2.8 to 10.5 | 0.001 |
5 | Fully adjusted** | 6.3 | 2.6 to 10.0 | 0.001 |
6 | Fully adjusted model** and excluding records within 3 months either side of the start month | 9.5 | 4.3 to 14.7 | <0.001 |
Additional analyses | ||||
7 | Model 6 and including the 13 PReCePT trial intervention units | 9.6 | 4.4 to 14.8 | <0.001 |
8 | Model 6 and excluding units in one AHSN where implementation was delayed | 10.0 | 3.9 to 16.0 | 0.001 |
*Percentage point changes, post implementation minus pre-implementation.
†Crude regression of uptake post implementation compared with pre-implementation.
‡As per model 1, plus additionally weighted on the number of eligible records per unit, with robust SEs.
§As per model 2, plus additionally accounting for clustering by AHSN, with robust SEs.
¶As per model 3, plus additionally adjusted for recorded start month.
**As per model 4, plus additionally adjusted for birth weight adjusted for gestational age and sex, maternal age, IMD, ethnicity, multiple birth, maternal hypertension (all unit-level aggregates), level of unit and study month.
††MgSO4 data from records on singleton births and the first born of multiples with records in the data set.
AHSN, Academic Health Science Network; IMD, Index of Multiple Deprivation; MgSO4, magnesium sulfate; NPP, National PReCePT Programme; PReCePT, Preventing Cerebral Palsy in Pre Term labour.