RETRACTED: Normative Data for the D-KEFS Tower Test in Greek Adult Population Between 20 and 85 Years Old.

Background

The Delis-Kaplan Executive Function System (D-KEFS) Tower Test (TT) is a widely used neuropsychological tool that assesses complex executive functions, including planning, cognitive flexibility, inhibition, switching, and impulsivity-key abilities often impaired in individuals with frontal dysfunction. Aims: There is currently no normative data for the D-KEFS TT in the Greek population. Consequently, it cannot be effectively used to detect executive dysfunction in neurological and psychiatric populations or for research purposes.

Methods

The study sample included 249 healthy adults (28.9% male, 71.1% female) aged 20 to 85 years (M = 46.53, SD = 17.41), with educational levels ranging from secondary school graduates to master's degree holders. Pearson correlation was used to examine the relationship between age and D-KEFS TT performance, while chi-square test assessed the effects of education and gender. Normative data were then derived from raw scores and converted into percentiles.

Results

Norms were established for the following D-KEFS TT variables: Total Achievement Score, Total Rule Violations, Move Accuracy Ratio, Mean First Move Time, and Time-per-Move Ratio. Age was the strongest predictor of performance, and normative data were stratified accordingly for the Greek adult population.

Conclusions

This study introduces the D-KEFS TT as a neuropsychological assessment tool for Greek adults across different age groups to evaluate complex executive functions throughout the lifespan. Unlike other D-KEFS tests, the TT had not previously been adapted for the Greek population. This study is the first to provide normative data, supporting its use in clinical practice and research.