Table 1 Secondary objectives and associated outcomes

1

To examine participant recruitment and identify barriers to recruitment

• The proportion of eligible individuals agreeing to participate

• Reasons for declining to participate

2

To examine the suitability of two candidate primary outcomes for a full-scale trial

The extent and pattern of missing data, presence of floor/ceiling effects, and variability in responses in:

a) number of true positive and false positive screens identified by usual care and digital screening between baseline and 8 weeks postpartum

b) MINI at 6 months postpartum

3

To examine the suitability of other proposed clinical measures and health economic measures

The extent and pattern of missing data, presence of floor/ceiling effects, and variability in responses in:

• PHQ-9 (baseline and after positive screen)

• GAD-7 (baseline and after positive screen)

• MINI (8 weeks)

• Postpartum Bonding Questionnaire (8 weeks, 6 months)

• Healthcare Resource Use Questionnaire (baseline, 8 weeks, 6 months)

• EQ-5D-5L (baseline, 8 weeks, 6 months)

4

To examine the acceptability and usability of the digital screening system and participants’ experiences of using it

Qualitative (interview) and quantitative (MARS) data from participants in the app use group regarding app acceptability, usability, and experiences of using the digital screening system

5

To examine the safety of the digital monitoring system and study procedures

The number of adverse events (AEs) and serious adverse events (SAEs) and whether they are judged to be related to the app or other study procedures