Use of the Patient Health Questionnaire (PHQ-9) in Practice: Interactions between patients and physicians

Abstract

We analyze the use of the Patient Health Questionnaire (PHQ-9), an instrument that is widely used in diagnosing and determining the severity of depression. Using conversation analysis, we show how the doctor deploys the PHQ-9 in response to the patient’s doubts about whether she is depressed. Rather than relaying the PHQ-9 verbatim, the doctor deviates from the wording so that the response options are selectively offered to upgrade the severity of the patient’s symptoms. This works in favor of a positive diagnosis and is used to justify a treatment recommendation that the patient previously resisted. This contrasted with the rest of the dataset, where diagnosis was either not delivered (as patients are presenting with ongoing problems) or was delivered without using the PHQ-9. When clinician-administered, the PHQ9 can be influenced by how response items are presented. This can lead either to downgrading or upgrading the severity of depression.