Factor structure and measurement invariance across various demographic groups and over time for the PHQ-9 in primary care patients in Spain

JUAN ANTONIO MORIANA ELVIRA2026-01-292026-01-29201810.1371/journal.pone.01933562-s2.0-85042486634https://www.scopus.com/inward/record.uri?eid=2-s2.https://ucocris.uco.es/handle/123456789/28923MultidisciplinaryFactor structure and measurement invariance across various demographic groups and over time for the PHQ-9 in primary care patients in Spainresearch article