Short-term memory outcome measures: Psychometric evaluation and performance in youth with Down syndrome.

BACKGROUND:Improving short-term memory (STM) performance for individuals with Down syndrome (DS) has been a target of recent clinical trials. Validation of STM outcome measures is essential for research rigor in trials among children and adolescents with DS. AIMS:The current study investigated the psychometric properties of four direct STM assessments and one everyday memory parent form. METHODS AND PROCEDURES:Measures were administered to a sample of 74 youth with DS at two visits, two weeks apart. Overall cognitive abilities were also assessed. OUTCOMES AND RESULTS:The OMQ-PF had good feasibility and distribution of scores, but floor effects were prominent for direct measures. Test-retest reliability was poor to moderate for all measures and practice effects were problematic for the NEPSY-II List Memory and DAS-II Recall of Objects subtests. Commonalities in responses were observed, including primacy/recency effects, and some STM scores were correlated with overall cognitive abilities. CONCLUSIONS AND IMPLICATIONS:The OMQ-PF met most study criteria, but no direct measure met sufficient criteria to be strongly recommended for future clinical trials. Because higher cognitive abilities were related to assessment completion, STM measures may require adaptation for use in broader samples of youth with DS across all levels of cognitive ability.