SUMMARY This study investigated the relationship between self-reported sleep factors (sleep duration, insomnia, use of sleeping medicine, probable sleep apnoea and feelings of fatigue and tiredness) with cognitive functioning in 5177 people aged 30 years or older from a cross-sectional representative sample of the adult population in Finland (The Finnish Health 2000 Survey). Previous studies have indicated a U-shaped association between increased health risks and sleep duration; we hypothesized a U-shaped association between sleep duration and cognitive functioning. Objective cognitive functioning was assessed with tasks derived from the Consortium to Establish a Registry for AlzheimerÕs Disease test battery (verbal fluency, encoding and retaining verbal material). Subjective cognitive functioning and sleep-related factors were assessed with questionnaires. Health status was assessed during a health interview. Depressive and alcohol use disorders were assessed with the Composite International Diagnostic Interview. Medication was recorded during the health examination. Short and long sleep duration, tiredness and fatigue were found to be associated with both objectively assessed and self-reported decreased cognitive functioning. The association was stronger between sleep factors and subjective cognitive function than with objective cognitive tests. These data suggest that self-reported habitual short and long sleep duration reflect both realization of homeostatic sleep need and symptom formation in the context of the individualÕs health status.

Perceived age predicted worsening of health as described as mortality. Perceived age may indicate general well-being and faith in the future, potentially reflecting changes in health.

Purpose: Mobility limitations and cognitive disorders have often been observed as risks for institutionalization. However, their combined effects on risk of institutionalization among initially community-dwelling older people have been less well reported. Design: A prospective cohort study with 10-year surveillance on institutionalization. Subjects: Study population (n = 476) consisted of 75- and 80-year-old people who were community-dwelling, had not been diagnosed with dementia, and participated in tests on walking speed and cognitive capacity at a research centre. Measures: Cognitive capacity was measured with three validated psychometric tests that were from the Wechsler Adult Intelligence Scale, Wechsler Memory Scale and Schaie- Thurstone Adult Mental Abilities Test. Mobility was measured with walking speed over a 10-m distance. Exclusive distribution based study groups were formed with cut-offs at the lowest third as follows: no limitation, solely mobility limitation, solely cognitive deficits, and combined mobility limitation and cognitive deficits. Cox proportional hazards model was used to determine the relative risks of institutionalization for the study groups. Results: Eleven percent of the participants were institutionalized during the 10-year surveillance. The risk for institutionalization was 4.9 times greater (95% confidence interval: 2.1–11.2) for those who had co-existing mobility limitations and cognitive deficits than for those with no limitations. Conclusions: The findings show that the accumulation of limitations in physical and cognitive performance substantially decreases the possibility for a person remaining at home. This might be due to a decreased reserve capacity and ineffective compensatory strategies. Therefore, interventions targeted to improve even one limitation, or prevent accumulation of these risk factors, could significantly reduce the risk of institutionalization.

The purpose of this prospective study was to describe changes in subjective age over an 8-year period among community-dwelling people aged 65 to 84 years in Finland. At the baseline 1155 respondents met study criteria and 451 of these participated in the follow-up study. Participants described in years the age they felt themselves to be (feel age) and their preferred age (ideal age). Discrepancy scores relative to chronological age were calculated for feel age and ideal age. No significant mean-level changes were observed in the age discrepancy scores over the 8-year time frame. The baseline discrepancy between chronological and feel age remained constant among 48% of the participants, with 26% reporting a younger and 26% an older feel age. Similar patterns were observed in the discrepancy between chronological age and ideal age. The findings point both to stability and to individual variability in feel and preferred age identification over time in older adults.

A person-oriented approach was used in a study of age identification among community-dwelling older people. The study was based on 8-year follow-up data; 843 persons aged 65-84 were involved in the first phase of the study, and 426 persons aged 73-92, in the second phase. Loosely, on the basis of the distinction between successful, usual, and pathological aging (Rowe & Kahn, 1987, 1997), participants were grouped according to their self-ratings of cognitive and physical functioning as "Positive," "Negative," and "Others." Participants possessing at least 4 out of the 5 criteria used as indicators of successful aging in the study (no illness or injury presenting problems in daily life, no health problems imposing limitations on hobbies, self-rated cognitive functioning better than satisfactory, age-comparative functional capacity as good, and no signs of depression) were assigned to the "Positive" group. The results showed these individuals typically to have a more youthful age identity, indicated by a lower feel age and thus a lower subjective age-perception score, lower mental, physical, and look ages, and a less frequently reported sense of age weighing on them. Moreover, this group reported a higher ideal age and had a chronological age satisfaction score closer to 0, suggesting higher satisfaction with chronological age. Also a tendency to set the onset of old age later and a willingness to live to 100 years of age were features that were more characteristic of the "Positive" than the other groups. The findings, supported by multivariate analyses, were in line with those of previous variable-oriented studies on age identification, suggesting that an association exists between perceptions of personal aging and physical and psychological well-being.