Feasibility, Test-Retest Reliability and Convergent Validity of the Two-Minute Step Test in Older Adults With Intellectual Disabilities.

The study used a complete case analysis for reliability and validity, which excluded participants with missing data. This subgroup had less severe intellectual disabilities and lived more often in community settings, potentially introducing selection bias. The sample was drawn from a larger cohort and may represent the better-functioning group of older adults with intellectual disabilities, limiting generalizability to those living independently without formal support. No formal inter-rater reliability assessment was performed, although testers were trained and experienced. A learning effect was observed, with higher scores on the second test, suggesting that a practice trial may be necessary for accurate assessment.

The HA-ID cohort study was funded by the Academic Collaborative Research Center Healthy Ageing and Intellectual Disabilities, a consortium of three Dutch care organizations. The care organizations were not involved in data processing, analysis, or manuscript writing. The authors declare no conflicts of interest.

Do not assume the 2MST is suitable for all older adults with intellectual disabilities. It had low feasibility for those with severe or profound disabilities and was impossible for wheelchair users. Also, note the learning effect: scores improved on the second attempt, so a practice trial is recommended before recording a final score.