Figure 1.

Schematic Outline of classification tool development and evaluation study. Event notes are free-text fields, where day-to-day notes can be recorded in any layout or format. Correspondence notes are used to attach any formal correspondences between patient and clinical staff or between clinical staff members. These documents constitute of letters and questionnaires recorded in word documents (which included any electronic questionnaires administered to the patient), pdf documents and any other documents related to the patient. “Suicid* ideat*” is the text pattern used to filter variations of the phrase “suicidal ideation”, within each sentence in the clinical notes, where the asterisk denotes a wild card allowing for any combination of letters in the word after the initial specified sequence.