Using Classical Test Theory to Determine the Psychometric Properties of the Deglutition Handicap Index.

The study did not check reliability over time because participants were not measured more than once. It did not check responsiveness, meaning whether the score changes when swallowing improves or worsens. The analysis used Classical Test Theory only, and the authors say this is a first step, not a full psychometric evaluation. Classical Test Theory findings depend on the sample, so they may not transfer unchanged to other populations. There is no international consensus on the best way to interpret FEES or VFS as the reference standard. Healthy controls were relatives and caretakers of patients, not a general healthy sample. Severe cognitive impairments were excluded, so the findings do not cover that group. The recruited patient count was 453, but floor and ceiling analyses report 395 participants, so the analysed sample is not fully explained. The paper gives two different total-score ranges: 0 to 120 in the questionnaire description and 0 to 12 in interpretability, so the exact meaning of the cut-off of 8 is unclear from the supplied text. The three-domain factor model explained 41.6% of variance, below the 50 to 60% range the paper cites as expected.

The supplied text names the University of Oslo (including Oslo University Hospital) as funder. It does not provide an author conflict-of-interest disclosure list.

Do not treat a DHI total score of 8 as a stand-alone diagnosis of dysphagia. The cut-off was checked against FEES or VFS in one French sample, and the authors say Classical Test Theory is only a first step.