Background: TMA-93 examines relational binding using images. The test has been proven to be discriminative for diagnosing early Alzheimer's disease by biomarkers. Norms for this test are available, but the elderly, at high risk for Alzheimer's disease, have not yet been widely represented.
Objective: To extend normative data on the TMA-93 for people aged 75 and over.
Methods: An extension of the Spanish TMA-93 normative study was undertaken. Only cognitively unimpaired people aged 75 and over were included. Age, gender, and educational attainment were registered as socio-demographic variables. Using histograms analysis, median comparisons, and linear regression analysis, we selected variables that demonstrated influence on TMA-93 total scores and provided percentile-base reference data according to combinations of those variables.
Results: We included 431 new participants, resulting in a total sample of 657 individuals (median age = 78, interquartile range = 76-81, range = 75-93). Percentile-base reference data stratified by a combination of age ranges (75-79, n = 428; and ≥80 years, n = 229), and educational attainment (< first grade, n = 253; first grade, n = 209; > first grade, n = 195) revealed that participants achieved a minimum TMA-93 total score of 26/30 at the 50th-percentile regardless of stratum. At the 10th-percentile, a maximum of 24/30 was achieved in the more educated stratum contrasting with a minimum of 19/30 in the less educated stratum.
Conclusion: Although mitigated by lower levels of education, performance on the TMA-93 is widely preserved in cognitively unimpaired people aged 75 and over. The test could facilitate the screening of elderly patients with memory complaints.
Keywords: Alzheimer’s disease; TMA-93; binding; elderly; illiterate; normative data.