Table 1.

Classification of risk by self-reported measures

Classification	Self-report at risk pre-birth	Self-report at risk year 1		Self-report at risk year 2
Self-reported measure	GHQ-28	GHQ-28	Kessler-6	GHQ-28	Kessler-6
Timing	Pregnancy	6 months	12 months	18 months	24 months
Considered ‘at risk’ if	Score is ≥75th centilea	At least one score is ≥75th centilea		At least one score is ≥75th centilea
Missing if	Score is missing	Both scores are missing		Both scores are missing

^aCentiles were calculated within ethno-language group to minimise variation caused by potential measurement inconsistencies