extended · article · 2019

Diagnosing depression in primary care: a Rasch analysis of the major depression inventory

Kaj Sparle Christensen; Eva Oernboel; Marie Germund Nielsen; Per Bech

OBJECTIVE: This study aims to assess the measurement properties of the Major Depression Inventory (MDI) in a clinical sample of primary care patients. DESIGN: General practitioners (GPs) handed out the MDI to patients aged 18-65 years on clinical suspicion of depression. SETTING: Thirty-seven general practices in the Central Denmark Region participated in the study. PATIENTS: Data for 363 patients (65% females, mean age: 49.8 years, SD: 17.7) consulting their GP were included in the analysis. MAIN OUTCOME MEASURES: The overall fit to the Rasch model, individual item and person fit, and adequacy of response categories were tested. Statistical tests for local dependency, unidimensionality, differential item functioning, and correct targeting of the scale were performed. The person separation reliability index was calculated. All analyses were performed using RUMM2030 software. RESULTS: Ite...