Multiple imputation was an efficient method for harmonizing the Mini-Mental State Examination with missing item-level data.

OBJECTIVE: The Mini-Mental State Examination (MMSE) is used to estimate current cognitive status and as a screen for possible dementia. Missing item-level data are commonly reported. Attention to missing data is particularly important. However, there are concerns that common procedures for dealing with missing data, for example, listwise deletion and mean item substitution, are inadequate. STUDY DESIGN AND SETTING: We used multiple imputation (MI) to estimate missing MMSE data in 17,303 participants who were drawn from the Dynamic Analyses to Optimize Aging project, a harmonization project of nine Australian longitudinal studies of aging. RESULTS: Our results indicated differences in mean MMSE scores between those participants with and without missing data, a pattern consistent over age and gender levels. MI inflated MMSE scores, but differences between those imputed and those without missing data still existed. A simulation model supported the efficacy of MI to estimate missing item level, although serious decrements in estimation occurred when 50% or more of item-level data were missing, particularly for the oldest participants. CONCLUSIONS: Our adaptation of MI to obtain a probable estimate for missing MMSE item level data provides a suitable method when the proportion of missing item-level data is not excessive.

Psychological well-being is an independent predictor of falling in an 8-year follow-up of older adults.

A population-based sample (N = 787) was followed for 8 years and assessed three times on measures of well-being (depressive symptoms, morale, and control) and fall history. Marginal models assessed the association between baseline well-being measures and falling. Random effects models assessed change in well-being indicators as well as change in fall rate over 8 years. After adjustment for sociodemographics, psychotropic medication, health, and sensorimotor function, our results showed that depressive symptoms, control, and morale were risk factors for subsequent falling, and an increase in depressive symptoms or a reduction in morale was associated with an increasing fall rate. We conclude that the three well-being measures are independently associated with falling and need to be considered in fall-risk assessments and population-based prevention and intervention strategies.

Prevalence and risk factors for depression in a longitudinal, population-based study including individuals in the community and residential care.

OBJECTIVE: The authors report the population prevalence of depression in older adults living in the community and in residential care. Demographic, medical, health behavior, functional and cognitive measures, and transition to residential care are evaluated as risk factors for depression over eight years. METHODS: Depression prevalence estimates were obtained from the initial electoral role sample of the Australian Longitudinal Study of Ageing that included persons living in residential care. A subsample (N = 1,116) based on follow-up data were included in longitudinal multilevel analyses that evaluated between-person and within-person predictors associated with scores from the Center for Epidemiology-Depression Scale. RESULTS: At wave 1, 14.4% of community-dwelling and 32.0% of residential care-dwelling participants were depressed (15.2% of total cases). Increase in depression was associated with antidepressant status, sex, education, and marital status, but not history of hypertension, stroke, diabetes, heart disease, or smoking. Time-varying predictors, including residential care, activities of daily living, instrumental activities of daily living, self-rated health, and Mini-Mental State Examination, predicted depressive symptoms both between and within persons. CONCLUSIONS: Depression is strongly linked with factors indicating increased dependency. Risk assessment and targeting of intervention strategies to prevent depression in late life should incorporate changes in functional capacity, mental status, and need for residential care.

Smoking as a risk factor for dementia and cognitive decline: a meta-analysis of prospective studies.

The authors assessed the association of smoking with dementia and cognitive decline in a meta-analysis of 19 prospective studies with at least 12 months of follow-up. Studies included a total of 26,374 participants followed for dementia for 2-30 years and 17,023 participants followed up for 2-7 years to assess cognitive decline. Mean study age was 74 years. Current smokers at baseline, relative to never smokers, had risks of 1.79 (95% confidence interval (CI): 1.43, 2.23) for incident Alzheimer's disease, 1.78 (95% CI: 1.28, 2.47) for incident vascular dementia, and 1.27 (95% CI: 1.02, 1.60) for any dementia. Compared with those who never smoked, current smokers at baseline also showed greater yearly declines in Mini-Mental State Examination scores over the follow-up period (effect size (beta)=-0.13, 95% CI: -0.18, -0.08). Compared with former smokers, current smokers at baseline showed an increased risk of Alzheimer's disease (relative risk=1.70, 95% CI: 1.25, 2.31) and an increased decline in cognitive abilities (effect size (beta)=-0.07, 95% CI: -0.11, -0.03), but the groups were not different regarding risk of vascular dementia or any dementia. The authors concluded that elderly smokers have increased risks of dementia and cognitive decline.

The impact of cataract surgery on visual functioning, vision-related disability and psychological distress: a randomized controlled trial.

PURPOSE: Determine whether there are changes in visual functioning, vision-related disability, health status and mood after cataract surgery. METHODS: 45 adults (mean age = 73.7 years) with bilateral cataract needing surgery for the first eye were recruited from public ophthalmology clinics. The Visual Functioning-14 survey assessed visual disability. Minimal angle of resolution tested visual acuity, and the Melbourne Edge Test examined contrast sensitivity. Demographic, psychological, health and medication use variables were examined. Participants were randomized to either an intervention or control arm. Controls were assessed on two occasions at a 3-month interval before having surgery. The intervention group was assessed 1-2 weeks before surgery and then reassessed 3 months after surgery. RESULTS: Visual functioning improved for those who had cataract surgery with better visual acuity in the better (P = 0.010) and worse (P = 0.028) eye compared with controls. The intervention group reported fewer difficulties with overall vision-related disability (P = 0.0001), reading (P = 0.004) and instrumental activities of daily living (P = 0.010) post-surgery compared with controls. People with improved depression scores (P = 0.048) after surgery had less difficulty with reading compared with those with unchanged or worsened depression scores. Cataract surgery did not improve health status. CONCLUSIONS: First eye cataract surgery is effective in improving outcomes in visual functioning and disability. Improved mood after surgery was related to less vision-related disability compared with unchanged or worse depression.

Weekly alcohol consumption, brain atrophy, and white matter hyperintensities in a community-based sample aged 60 to 64 years.

OBJECTIVE: The objective of this study was to determine the association between weekly alcohol consumption and brain atrophy in adults aged 60 to 64 years. METHODS: Brain magnetic resonance imaging scans from 385 adults recruited through a community survey were analyzed. Automated segmentation and manual tracing methods were used to obtain brain subvolumes and automated methods were used to obtain quantification and localization of white matter hyperintensities. Visual measures of cortical atrophy were obtained as were data on health and lifestyle factors. Alcohol consumption was assessed with the Alcohol Use Disorders Identification Test. RESULTS: In men, weekly alcohol consumption had a positive linear association with ventricular volume and gray matter and a negative linear association with white matter. In women, weekly alcohol consumption had a nonlinear relationship with cerebrospinal fluid and white matter. Alcohol consumption was not associated with white matter hyperintensities, corpus callosum size, hippocampal or amygdala volumes in analyses adjusting for confounding variables. CONCLUSION: An association between alcohol consumption and brain atrophy is evident at the population level. In women, detrimental effects of alcohol on the brain appear to occur at lower levels of consumption. It remains possible that low levels of alcohol consumption have neuroprotective benefits but is clear that high levels of consumption are detrimental.

The effect of cataract surgery on neuropsychological test performance: a randomized controlled trial.

Recent cross-sectional studies have reported strong associations between visual and cognitive function, and longitudinal studies have shown relationships between visual and cognitive decline in late life. Improvement in cognitive performance after cataract surgery has been reported in patients with Mild Cognitive Impairment. We investigated whether improving visual function with cataract surgery would improve neuropsychological performance in healthy older adults. A randomized clinical trial of cataract surgery performed at acute hospitals was conducted on 56 patients (mean age 73) with bilateral cataract, after excluding a total of 54 patients at the screening stage, of whom 53 did not meet visual acuity criteria and one did not have cataract. In-home assessments included visual and neuropsychological function, computerized cognitive testing and health questionnaires. Results showed no cognitive benefits of cataract surgery in cognitively normal adults. We conclude that visual improvement following cataract surgery is not strongly associated with an improvement in neuropsychological test performance in otherwise healthy adults. Joint associations between visual and cognitive function in late life are likely to be due to central factors, and unlikely to be strongly related to eye disease. Short-term increased neural stimulation from improved visual function does not appear to affect cognitive performance.

An 8-year prospective study of the relationship between cognitive performance and falling in very old adults.

OBJECTIVES: To determine whether cognitive performance, as distinct from cognitive impairment, predicts falling during an 8-year follow-up in a community-based sample of very old adults and to evaluate how cognitive change is associated with falling. DESIGN: Prospective cohort study including three waves of data collected in 1992, 1994, and 2000. SETTING: Population based, with the baseline sample drawn from the electoral roll. PARTICIPANTS: Inclusion criteria were completion of at least three cognitive tests at baseline and completion of the falls questionnaire at Wave 6 (N=539). MEASUREMENTS: Assessments of health and medical conditions, visual acuity, cognitive function, functional reach, semitandem stand, and grip strength were conducted in 1992 (baseline), 1994, and 2000. Self-report information on falls in the previous 12 months was obtained on each of these occasions. Marginal models using generalized estimating equations were used to assess the association between baseline cognitive performance and falling over 8 years, adjusting for sociodemographic, health, and sensorimotor variables. Random effects models were used to assess the relationship between change in cognitive performance and change in fall rate and fall risk over 8 years. RESULTS: Mini-Mental State Examination and verbal reasoning at baseline predicted rate of falling over an 8-year period. Within individuals, declines in verbal ability, processing speed, and immediate memory were associated with increases in rates of falling and fall risk. CONCLUSION: Cognitive performance is associated with falling over 8 years in very old adults and should be assessed in clinical practice when evaluating short- and long-term fall risk.