Polish Adaptation and Initial Psychometric Evaluation of the Hungarian Aphasia Screening Test (HAST-PL)

Background/Objectives: This study developed a Polish adaptation of the Hungarian Aphasia Screening Test (HAST-PL) and evaluated its internal structure, internal consistency, and screening accuracy. Methods: Following translation and expert-led adaptation, 173 stroke survivors (130 with clinically confirmed aphasia and 43 without aphasia) were analysed. Clinical status was established before HAST-PL through neurological and speech-language assessment supplemented by medical records. Analyses included ordinal confirmatory factor analysis (CFA), internal consistency, group comparisons, ROC analysis, and 20,000 stratified bootstrap resamples with repeated cut-off selection. CFA was also performed in the aphasia group. Results: The one-factor model yielded CFI = 0.991, TLI = 0.981, RMSEA = 0.086, and SRMR = 0.051; the aphasia-only analysis showed a similar pattern. Internal consistency was acceptable (α = 0.805; ω = 0.834). All five tasks differentiated the groups (p ≤ 0.028). AUC was 0.88 (95% CI [0.83, 0.93]). Screen-positive scores ≤16 yielded 66.2% sensitivity and 97.7% specificity; ≤17 yielded 77.7% and 86.0%, respectively. The apparent maximum Youden index of 0.6383 decreased to 0.6141 after bootstrap correction. The ≤16 and ≤17 rules were selected in 51.265% and 47.950% of resamples, respectively. Conclusions: HAST-PL shows initial promise for aphasia screening. Internal validation supports evaluating both neighbouring thresholds rather than adopting either as a definitive clinical rule. Negative results cannot exclude clinically suspected aphasia, and independent external validation remains necessary.