Psychometric evaluation of a 6‐item C hinese version of the H amilton D epression R ating S cale: Mokken scaling and item analysis

Background It is unclear whether the 6‐item Melancholia subscale of the Hamilton Depression Rating Scale (HAM‐D 6 ) has better psychometric properties than the parental 17‐item version (HAM‐D 17 ) in the Chinese populations. Methods The study was to check the Chinese HAM‐D 17 and HAM‐D 6 for reliability and validity with Mokken scale analysis and item analysis. We reanalyzed a clinical sample of adult psychiatric outpatients (N = 214; age, mean (SD) = 38.3 (10.5) years; 63.1% female) in Taiwan. Results Our Mokken scale analysis showed that the HAM‐D 6 was a moderate unidimensional scale (H s  = 0.44) while the HAM‐D 17 was not (H s  = 0.26). The 5 items of the HAM‐D 6 had strong invariant item ordering (H T  = 0.58). The HAM‐D 17 and HAM‐D 6 had comparable reliability (α = 0.79) and validity ( r  = 0.91), and the HAM‐D 6 was more homogenous than the HAM‐D 17 . To predict depression in remission (HAM‐D 17  ≤ 7), the best cutoff of the HAM‐D 6 was 4 (specificity, 87.5%; sensitivity, 100%; positive predictive value, 56.0%; negative predictive value, 100%). Discussion The Chinese HAM‐D 6 was a reliable, valid, and unidimensional scale of depression.