title: The Letter Digit Substitution Test: normative data for 1,858 healthy participants aged 24-81 from the Maastricht Aging Study (MAAS): influence of age, education, and sex.
abstract: The Letter Digit Substitution Test (LDST) is based on earlier developed substitution tests (e.g., Digit Symbol Substitution Test) but uses over-learned signs instead of the symbols used in other substitution tests. The written and oral versions of the LDST were administered to a large, cognitively screened sample (N = 1,858) of adults aged 24 to 81 years. Age was the most important predictor of LDST performance, and females outperformed males. A low level of education profoundly influenced LDST performance: the effect of a low versus high level of education on LDST performance was comparable to about 20 years of aging. Regression-based normative data were prepared for both the written and oral versions of the LDST.
authors.affiliation: Maastricht Brain and Behavior Institute, Maastricht University, Maastricht, The Netherlands. W.vanderelst@NP.unimaas.nl
authors.forename: Wim
authors.initials: W
authors.lastname: van der Elst
authors.forename: Martin P J
authors.initials: MP
authors.lastname: van Boxtel
authors.forename: Gerard J P
authors.initials: GJ
authors.lastname: van Breukelen
authors.forename: Jelle
authors.initials: J
authors.lastname: Jolles
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D009483:Neuropsychological Tests / Q000592:standards* / Q000706:statistics & numerical data; D012016:Reference Values; D012727:Sex Characteristics; D012737:Sex Factors