Analyzing the psychometric properties of the PHQ-9 using item response theory in a Chinese adolescent population

Table 2 Item parameters, Item fit and Factor loadings

	Discrimination parameter (α)	Threshold parameters (β)			Mean threshold	\({\text{X}}^2 - {\text{RMSEA}}\)	Loadings
	Discrimination parameter (α)	β₁	β₂	β₃	Mean threshold	\({\text{X}}^2 - {\text{RMSEA}}\)	Loadings
Item 1	2.843	0.731	1.459	2.189	1.459	0.009	0.724
Item 2	3.456	0.778	1.444	2.143	1.455	0.008	0.711
Item 3	2.651	0.820	1.490	1.993	1.434	0.008	0.704
Item 4	3.320	0.717	1.426	2.031	1.391	0.007	0.755
Item 5	2.531	0.946	1.658	2.237	1.613	0.012	0.672
Item 6	2.813	0.693	1.362	1.879	1.311	0.008	0.733
Item 7	1.927	0.982	1.722	2.439	1.714	0.009	0.595
Item 8	2.467	1.045	1.688	2.302	1.678	0.006	0.664
Item 9	2.725	1.167	1.701	2.318	1.728	0.012	0.671

\(\,\,{\text{X}}^2 .\,{\text{RMSEA}}\) = item-fit statistic; loadings = Factor loadings.

ISSN: 1744-859X