Table 1.

System usage variables extracted from the Horyzons platform.

Variable type	Variables
Therapy-related variables (number of)	Stepsa started Pathwaysb started Actionsc done Visits to suggested contentd Visits to messagese Visits to therapyf
Social networking–related variables (number of)	News feedg posts News feed comments Likes made Reactionsh made

^aSteps refer to the intervention modules.

^bPathways refer to a collection of intervention modules related to a topic (eg, anxiety).

^cActions refer to behavioral activities aiming to translate learning into behavior.

^dSuggested content refers to therapeutic content recommended by clinical moderators.

^eMessages refer to a private message section, where moderators could contact participants directly.

^fVisiting therapy refers to visiting the home page of the therapy component of the intervention.

^gThe news feed refers to the social network.

^hReactions refer to short support messages in response to a post (eg, thinking of you).