Table 1 Measures contained in the Mental Health and Wellbeing (MHWB) questionnaire

PHQ-8 [46, 47]

The PHQ-9 is a 9-item questionnaire which assesses the core symptoms of depression and their frequency in the past 2 weeks, rated from 0 (“not at all”) to 3 (“nearly every day”); here, the 8-item version was used, excluding the item on suicidality; cut points of 5, 10, 15 and 20 respectively indicate mild, moderate, moderately severe, and severe levels of depression [46, 47]; cut-off scores between 8 and 11 give acceptable diagnostic properties for detecting major depressive disorder in the general population [48]

GAD-7 [49]

7-item questionnaire which assesses the core symptoms of anxiety and their frequency in the past 2 weeks, rated from 0 (“not at all”) to 3 (“nearly every day”);cut points of 5, 10 and 15 respectively indicate mild, moderate, and severe levels of anxiety [49]; cut-off scores between 7 and 10 give acceptable diagnostic properties for identifying generalised anxiety disorder [50]

PHQ-15 [51]

15-item questionnaire which assesses somatic symptoms (e.g. headaches, dizziness, trouble sleeping) and their frequency in the past 4 weeks, rated from 0 (“not bothered at all”) to 2 (“bothered a lot”); total scores of 5, 10 and 15 respectively indicate low, medium and high levels of somatic symptom severity

LTE (List of Threatening Events) [52]

12-item questionnaire which assesses which of 12 life events (e.g. serious illness, unemployment) have occurred in the timeframe specified