Our primary objective is to assess the accuracy of aEEG against the reference standard cEEG for detection of 'neonates with seizures' and 'individual seizures'.

1. Detection of 'neonates with seizures': this refers to the ability of the index test to identify a 'neonate' as 'seizure positive' or 'seizure negative' correctly based on the detection of at least one seizure episode in the entire aEEG recording of the neonate.
2. Detection of 'individual seizures': this refers to the ability of the index test to identify an 'individual' seizure episode within the same neonate correctly rather than just diagnosing the neonate as 'seizure positive' or 'seizure negative'. Diagnosis of an 'individual seizure' episode is important for optimal management of seizures.

If data are available, we will perform subgroup analysis for seizure detection where duration of monitoring is less than or equal to six hours. This subgroup is particularly important as six hours is the cut-off point to decide whether infants with hypoxic ischaemic encephalopathy require therapeutic hypothermia (Shankaran 2005).

Our secondary objective is to investigate variation in the accuracy of aEEG according to the potential sources of between-study heterogeneity listed below.

1. To compare 'aEEG without raw trace' versus 'aEEG with raw trace'
2. To compare 'aEEG with raw trace' versus 'aEEG with raw trace and seizure detection algorithm'
3. To compare single versus two versus more than two channels
4. To compare different aEEG lead positions
5. To compare surface electrodes versus needle electrodes
6. To investigate the effect of training (yes/no) in the interpretation of aEEG
7. To investigate the effect of clinicians' experience (yes/no) in the interpretation of aEEG