Bramell-Risberg et al and limited generalization due to several factors, such as small study sample, few individuals above 80 years of age,7–9 study sampling from outpatient clinics7 or clinical trials,3 and selec- tion bias involving selection of best performers.4 In addition, exclusion of potential confounders such as disease condition and life habits7–9 have been found, as well as lack of control- ling for confounders.6–9 Physical performance tests performed at high speed may require additional physiological reserves and impose higher demands on overall balance and attention control.3 Some studies1,6,10 have only used tests at self-selected speeds, whereas walking at a fast speed, for example, has been found to be a more sensitive measure in differentiating levels of cognition.3 Different test methodologies and results, based on continuous, categorical, or composite measures, as well as the use of different rating systems, limit comparability. Impaired memory is an early indicator of cognitive impairment.11–13 Poor performance on delayed recall, as a marker of memory impairment,14 and tests of executive function, are associated with a high risk of progression to dementia.13,15,16 The Mini-Mental State Examination (MMSE), which addresses multiple cognitive domains, is widely used to detect cognitive impairment.17 To our knowledge, no previous study has described the association of cognitive impairment, assessed by the three-word delayed recall task of the MMSE, with separate physical tests. To increase generalization, this was analyzed in a large study sample from an elderly general population, controlling for known confounders. The aim was to investigate whether separate physical tests of the lower extremities, which assess movement speed and postural control, were associated with cognitive impairment in elderly community-dwelling subjects. Materials and methods Study population This investigation is part of an ongoing Swedish population study, “Good Aging in Skåne” (GÅS), which, in turn, is one of four components of the Swedish National Study on Aging and Care (SNAC).18 The GÅS study includes men and women from nine age cohorts – 60, 66, 72, 78, 81, 84, 87, 90, and 93 years of age – randomized from five munici- palities and covering both urban and rural areas using the National Municipality Registry. The GÅS study population was recruited between February 2001 and July 2004. Of the 4893 eligible subjects invited by letter to participate in the study, 2931 accepted the invitation (participation rate 60%). Subjects were investigated at the medical research center or, if that was inconvenient, in their own homes. 196 submit your manuscript | www.dovepress.com Dovepress Dovepress The exclusion criteria were dementia and stroke,19,20 based on clinical examination, medical history, or information found in the National Diagnosis Register (which includes diagnoses for all inpatient cases in Swedish hospitals since 1987), and impaired global cognitive function, defined as a score below 24 on the MMSE.17,20,21 Further exclusion criteria were depressive mood,19,20 defined as a mean score above 20 on the Montgomery–Asberg Depression Rating Scale (MADRS),22 and medication with neuroleptics.23 Based on these criteria, 761 subjects were excluded, and an additional 55 subjects were excluded due to not having performed the walking test at a self-selected walking speed or the step test. The total study population, thus, consisted of 2115 subjects – 974 men (46.1%) and 1141 women (53.9%), who were divided into three groups: 328 cases, 457 subjects in an intermediate group, and 1330 controls, according to the neuropsychological assessment by the MMSE. The 328 cases consisted of subjects who scored 0 out of 3 (0/3) on the three-word delayed-recall item of the MMSE. The intermediate group was made up of those who could recall one out of three words (1/3), and the 1330 controls scored 2/3 and 3/3. The majority of subjects, 2060 (97.4%), were examined at the research center, and 55 (2.6%) were examined in their own homes. Subjects examined at home were older (P , 0.001), and the proportion of women was higher than that of men – 67% versus 33% (P = 0.010). Data collection Data were collected from medical history, clinical examina- tion, neuropsychological evaluation, assessments of physical performance, and self-administered questionnaires regarding sociodemographic and health-related factors, ambulation, activities of daily living (ADL), and comorbidity. Measurements of global cognitive function and memory The MMSE21 was part of the neuropsychological evaluation. MMSE scores range from 0 to 30 points, with a score below 24 indicating impaired global cognitive function.17 The three-word delayed recall subtest of the MMSE, a brief measure of memory function,24 was used to define the degree of cognitive impairment. The subscores of this test have shown better validity to assess episodic memory than the total MMSE score.14 This subtest assesses the domain of episodic memory;14,25 its scores range from 0 to 3, reflecting the number of words correctly recalled. In the present study, Clinical Interventions in Aging 2012:7