Background: Prior studies regarding the risk factors of mild cognitive impairment (MCI), such as physical activity (PA) and sleep related factors in older Chinese populations are scarce, and the findings have not been consistent. Objectives: 1. To cross-sectionally and longitudinally examine the dose-response association between PA and cognitive function by Delayed Word Recall Test (DWRT) or Mini-mental State Examination (MMSE). 2. To cross-sectionally and prospectively examine the association of sleep related factors, including sleep duration, daytime napping, morning tiredness and insomnia, with cognitive function. Design: Cross-sectional and longitudinal analysis using both baseline and follow-up data from the GBCS. Methods Baseline data from 8,451 men and 22,067 women aged 50 years or above were used for the cross-sectional analysis. Among them, 4,214 men and 11,284 women participating in the second examination were included in the longitudinal analysis. Information on demographic, socioeconomic and lifestyle factors, and personal disease history was collected. Cognitive function was assessed by MMSE and DWRT under standardized protocols. Results 1. Significant dose-response relations across quintiles of metabolic equivalent value (METs) with DWRT score in participants with or without good self-rated health were found in cross-sectional analysis (all P for trend <0.001). 2. Prospectively, compared to those who were physically active, those with moderate activity or inactivity had increased risk for MCI. Regarding daily walking time, subjects with walking of 0.5 to 1 h, or ≥1 h had significantly reduced risk of MCI by 25% and 31% respectively compared with those who walked < 0.5 h per day. Subjects with low PA level at both baseline and follow-up had a significantly higher risk of MCI than those reporting PA at both baseline and follow-up. 3. Cross-sectionally, after adjustment for a range of potential confounders, an inverted U-shaped association between sleep duration and DWRT score was found, with 7 to 8 h of habitual sleep duration showing the highest score (P-values for trend from 3 to 7 h and from 7 to ≥10 h were all ≤0.001). Subjects with daily napping, morning tiredness, or insomnia had lower DWRT score than those without (P ranged from <0.001 to 0.01). 4. Prospectively, after adjustment for multiple risk factors, compared to sleep duration of 7 hours per day, those with sleep duration of 5 hours or less had increased risk for MCI by 43%. The adjusted P value for the linear trend from sleep duration of 3 hours to 7 hours per day was 0.01. The association remained after excluding those with poor health status. No significant associations of daytime napping, morning tiredness and insomnia with MCI were found. Conclusions In summary, we found a significant dose response association between PA and cognitive function in both cross-sectional and longitudinal analysis. One hour of daily walking is recommended for older Chinese people to delay or prevent cognitive decline. Short or long sleep duration may also be an important predictor of mild cognitive impairment. Sleep duration of less than 6 hours per day may indicate an increase risk of cognitive impairment in older people. / published_or_final_version / Community Medicine / Doctoral / Doctor of Philosophy

China has 9 million elderly individuals with dementia, which places it first in the world. Although family care remains the major source of support for people with dementia, residential care has become an indispensable choice in recent years. The biggest concern is the quality of life of the elderly with cognitive impairment or dementia (QOL-ECI) in residential care facilities (RCFs). Previous studies have explored many individual-level factors associated with QOL-ECI; however, less discussion has been conducted on how to improve it from an organizational-level perspective. China serves as a good research setting for this issue. The present study aims to establish an organizational-level framework to investigate QOL-ECI in RCFs. The Person-centered Care (PCC) Approach serves as an organizational strategy, and the High Commitment Work System (HCWS) is used as a human resource management practice. The study exposes the QOL-ECI status of RCFs in Xi’an China; and examines the relationship between PCC/HCWS and QOL-ECI respectively and jointly. A quantitative research method, survey in particular has been designed to achieve the research objectives, and has been conducted in two phases. Phase one of the study aims to validate a Chinese Version of the Person-centered care Assessment Tool (P-CATC), which is designed to measure the extent to which formal caregivers rate their facility as being person-centered. The resulting 24-item P-CAT-C is validated among a sample of full-time employees (n=330) in all 34 RCFs in urban Xi’an, a city in China. Phase two is a survey conducted among the same 34 RCFs. Full-time employees (n=330) evaluated the HCWS level for each RCF; residents with cognitive impairment (n=307) and their respective personal care workers (n=207) were invited to evaluate QOL-ECI. Hierarchical Linear Modeling (HLM) has been adopted to test the hypothesis. In phase one study, Confirmatory Factor Analysis (CFA) shows that a three-factor 15-item solution of the P-CAT-C provided adequate fit indices to the data (χ2 = 145.69, df = 81, p< 0.001, CFI = 0.93, TLI=0.91; RMSEA = 0.05). The internal consistency coefficient (Cronbach’s α=0.68) is satisfactory. The inter scale correlation shows good construct validity. The result of Phase two study shows that the total mean patient-rated QOL-ECI score is 36.06 (SD=8.16) and the caregiver-rated score is 34.09 (SD=6.88). Using caregiver-rated QOL-ECI as the dependent variable, the HLM regression analysis shows that PCC and HCWS are statistically significant with QOL-ECI respectively, and that the HCWS has a positive moderate effect on the relationship between PCC and QOL-ECI. Using patient-rated QOL-ECI as the dependent variable, the hypotheses are partially supported. This study is among the first to report the QOL-ECI status of RCFs in China. It initially demonstrates that PCC and HCWS are positively associated with QOL-ECI both respectively and jointly. It also primarily establishes an organizational-level framework to examine QOL-ECI. This will generate valuable implications and insight into research, practice and policy-making. Finally, this study further develops the PCC theory from an organizational perspective, and contributes to both management and social work literature by first adopting the HCWS for service organizations for the elderly. / published_or_final_version / Social Work and Social Administration / Doctoral / Doctor of Philosophy

published_or_final_version / Psychiatry / Doctoral / Doctor of Philosophy

Neuropsychological deficits have been implicated in Chronic Fatigue Syndrome (CFS) and there is some indication that cerebral efficiency is compromised in these patients. To further investigate the nature of this impairment, 20 patients who had received a medical diagnosis of CFS were neuropsychologically assessed and compared with age-, sex-, and education-matched controls (20 depressed and 20 healthy subjects). The test battery consisted of the Grooved Pegboard Trail Making Test, Symbol Digit Modalities Test, Auditory-Verbal Learning Test, Visual Design Learning Test, Controlled Oral Word Association Test and Paced Auditory Serial Addition Task. Additional measures included a CFS symptom checklist, SCL-90-R and Cognitive Failures Questionnaire (CFQ). Univariate statistical analysis revealed a significant difference between CFS patients and healthy individuals on only one measure; the "S" trial of the COWAT (F[2,59]=3.30, p <.05). This finding suggests the existence of subtle but detectable neuropsychological difficulty in executive or attentional mechanisms in CFS patients. Further analysis revealed that the observed finding could not be attributed to depression or medication side-effects. Although a trend of declining neuropsychological test performance was evident in moving across the spectrum of healthy, depressed, and CFS samples, this reached significance only for the CFS/depressed versus healthy comparison X22 [1] = 9.40, p < .05). The overall similarity of the neuropsychological profiles of CFS and depressed patients was noted, while an additional finding was the discrepancy between reported levels of subjective cognitive failure (CFQ) and objective neuropsychological findings in the CFS patients. The SCL-90-R profiles of the CFS and depressed patients were also found to be similar in terms of reported levels of psychological distress; however group discrimination was evident on two subscales (Somatization and Obsessive-Compulsive). Although the CFS and depressed controls did not differ with respect to levels of depression, there were some indications of a differential impact of depressive symptomatology on neuropsychological functioning. Taken together, the results of this study indicate that while subtle deficits are detectable in the neuropsychological profiles of CPS patients, the magnitude of impairment appears insufficient to significantly interfere with everyday cognitive functioning. / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1997.

The purpose of this investigation was to examine the validity of the Woodcock Johnson Tests of Cognitive Ability-Revised (WJTCA-R) in discriminating between individuals with neurological or psychiatric impairments and those without known impairment. The primary question was whether WJTCA-R Standard Battery test scores significantly differentiated between individuals with brain-damage (n = 36), depression (n = 21), and without known impairments (n = 32). Archival data obtained for the development of a new neuropsychological assessment measure utilizing the WJTCA-R was analyzed. The results of a discriminant functions analysis indicated that significant differences between the groups existed on the WJTCA-R. Based on WJTCA-R Standard Battery performance alone, participants had a 53% chance of being correctly classified into their diagnostic group. Brain-damaged individuals had the best chance of being correctly classified while correct classification of depressed individuals was only slightly greater than that obtained from random assignment. In addition to moderately supporting the use of a multi-factored, theory-driven assessment instrument, the results of this study have clinical relevance for the development of diagnosis-specific recommendations for brain-damaged and depressed individuals. / Department of Educational Psychology

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 4 uppsatser.

Thesis (M. Med. Sc.)--University of Hong Kong, 2007.

Thesis (Ph.D.)--City University of New York, 2003. / Includes bibliographical references (leaves 88-98).

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 5 uppsatser.