Executive performance in older Portuguese adults with low education.

Evaluation of executive functions is essential in clinical diagnosis, yet there are limited data regarding the performance of participants with low education. We present results on several measures of executive functions obtained in community-dwelling adults with an overall low education and study the effect of this variable in each test. A sample of 479 adults (64% female, mean age 66.4 years) was assessed by a battery comprising 13 measures of executive function (Trail Making Test; Symbol Search; Matrix reasoning; Semantic and phonemic verbal fluencies; Stroop test; and digit spans). Tests' psychometric properties and the effects of age, gender, and education were studied across education levels within each age group. Tests showed good psychometric properties. Education explained more variance than age in the majority of measures, with lower educational levels being significantly associated to worse scores. Tables are presented with mean scores, standard deviation, and the value of extreme percentiles for younger (50-65, N = 232) and older (>65 years, N = 247) × education (0-3, 4, 5-9, and >9 years) subgroups. Education-adjusted norms are necessary for an adequate interpretation of test results. The present data may be useful for clinicians caring for populations with low literacy.