Can clinicians use the PHQ-9 to assess depression in people with vision loss?

Abstract

PURPOSE.: To investigate whether the Patient Health Questionnaire-9 (PHQ-9) possesses the essential psychometric characteristics to measure depressive symptoms in people with visual impairment. METHODS.: The PHQ-9 scale was completed by 103 participants with low vision. These data were then assessed for fit to the Rasch model. RESULTS.: The participants' mean ± standard deviation (SD) age was 74.7 ± 12.2 years. Almost one half of them (n = 46; 44.7%) were considered to have severe vision impairment (presenting visual acuity <6/60 in the better eye). Disordered thresholds were evident initially. Collapsing the two middle categories produced ordered thresholds and fit to the Rasch model (χ = 1..