Normative data for the oldest old: Trail Making Test A, Symbol Digit Modalities Test, Victoria Stroop Test and Parallel Serial Mental Operations

Normative data for evaluating cognitive function in the oldest old, aged 85 years and above, are currently sparse. The normative values used in clinical practice are often derived from younger old persons, from small sample sizes or from broad age spans (e.g. >75 years) resulting in a risk of misjudgment in assessments of cognitive decline. This longitudinal study presents normative values for the Trail Making Test A (TMT-A), the Symbol Digit Modalities Test (SDMT), the Victoria Stroop Test (VST) and the Parallel Serial Mental Operations (PaSMO) from cognitively intact Swedes aged 85 years and above. 207 participants, born in 1922, were tested at 85, 90 (n = 68) and 93 (n = 35) years of age with a cognitive screening test battery. The participants were originally recruited for participation in the Elderly in Linkoping Screening Assessment. Normative values are presented as mean values and standard deviations, with and without adjustment for education. There were no clinically important differences between genders, but education had a significant effect on test results for the 85-year-olds. Age effects emerged in analyses of those participants who completed the entire study and were evident for TMT-A, SDMT, VST1 and PaSMO. When comparisons can be made, our results are in accordance with previous data for TMT-A, SDMT and VST, and we present new normative values for PaSMO.