Social and Behavioral Sciences Commons^™

Distinguishing Between Symptom Presence And Severity Using A Two-Part Sequential Model, Luiza Ferreira Pradera

Theses and Dissertations

Most symptom measures either implicitly or explicitly distinguish between symptom presence and symptom severity. For example, item 2 on the PHQ-9, a commonly used measure of depressive symptoms, asks respondents to rate how much they have been 'feeling down, depressed, or hopeless.' The response options are 0 (Not at all), 1 (Several Days), 2 (More than half the days), and 3 (Nearly every day). Answering 0 indicates that the symptom is not present, and any response greater than 0 suggests the symptom is present. Higher values indicate higher severity of the symptom. Although the response options distinguish between symptom presence …