Table 4: Measurement items in the patients questionnaire.

Construct Items Survey Item References
Predisposing Factors - Gender, age, education, experience of social media usage, social media platform used and total time per day (hours). Adapted from [80]
Information Factors (INF) INF1 ‘Advice from experts, friends and relatives makes me interested in joining a secret group and in seeking health information and lifestyle interventions through social media.’ Adapted from [71, 74, 81]
Information Factors (INF) INF2 ‘Advice from other participants on social media influences my health behaviour.’ Adapted from [71, 74, 81]
INF3 ‘Joining a secret group and seeking health information from social media interventions allowed me to share lifestyle experiences such as food menus, exercise methods and sleeping patterns, which is useful to other participants.’
INF4 ‘Joining a secret group and seeking health information and interventions on social media have allowed me to get information and advice on how to live healthier including helpful food menus, exercise and getting enough sleep.’
Awareness Factors (AWN) AWN1 ‘I perceive the benefits of joining a secret group and seeking health information for depressive diseases by seeking lifestyle interventions on social media that will encourage good health behaviour.’ Adapted from [58, 61, 71, 72]
AWN2 ‘I acknowledge that joining a secret group and seeking health information about depressive diseases by interacting on social media helps me to contact and exchange information with other participants.’
AWN3 ‘I perceive that I can find health and lifestyle information such as food menus, exercise methods and sleeping patterns by participating on social media.’
AWN4 ‘I can learn to join a secret group and seek health information about depressive diseases by quickly interacting on social media.’
AWN5 ‘Joining a secret group and seeking health information will help stimulate me to improve my healthy behaviour.’
AWN6 ‘My personal technology preferences made me interested in joining a secret group and seeking health information by interacting on social media.’
Motivation Factors (MOT) MOT1 ‘I think that joining a secret group and seeking health information about depressive diseases is beneficial for my health habits.’ Adapted from [72, 73, 74, 76, 81]
MOT2 ‘The support from experts, friends and relatives contributed to my decision to use secret groups and to seek health information about depressive diseases by interacting on social media.’
MOT3 ‘Experts, friends and relatives have encouraged me to use secret groups and seek health information about depressive diseases by interacting on social media.’
MOT4 ‘I think it is easy to use secret groups and seek health information about depressive diseases by interacting on social media.’
MOT5 ‘I think I will get the right information and be safe when using secret groups and seeking health information about depressive diseases while interacting on social media.’
Barrier (BAR) BAR1 ‘I cooperate with and follow the advice of experts on the use of secret groups and seeking health information about depressive diseases when interacting on social media.’ Adapted from [75]
BAR2 ‘I cooperate with experts by providing information related to treatment.’
Intention to Change Health Behaviours (INT) INT1 ‘I accept the guidelines for the development of a lifestyle intervention model on social media to change health habits both in the form of secret groups and in finding health information about depression.’ Adapted from [54, 81]
Intention to Change Health Behaviours (INT) INT2 ‘I am ready to change my health habits during the next six months to help develop a lifestyle intervention programme using social media.’ Adapted from [54, 81]
INT3 ‘I intend to change my health behaviour in the next six months if there is a development programme of intervention on social media.’