Interim follow-up of a randomized controlled trial comparing Chinese style mind body (Tai Chi) and stretching exercises on cognitive function in subjects at risk of progressive cognitive decline.

OBJECTIVES: We reported the interim findings of a randomized controlled trial (RCT) to examine the effects of a mind body physical exercise (Tai Chi) on cognitive function in Chinese subjects at risk of cognitive decline. SUBJECTS: 389 Chinese older persons with either a Clinical Dementia Rating (CDR 0.5) or amnestic-MCI participated in an exercise program. The exercise intervention lasted for 1 year; 171 subjects were trained with 24 forms simplified Tai Chi (Intervention, I) and 218 were trained with stretching and toning exercise (Control, C). The exercise comprised of advised exercise sessions of at least three times per week. RESULTS: At 5th months (2 months after completion of training), both I and C subjects showed an improvement in global cognitive function, delayed recall and subjective cognitive complaints (paired t-tests, p < 0.05). Improvements in visual spans and CDR sum of boxes scores were observed in I group (paired t-tests, p < 0.001). Three (2.2%) and 21(10.8%) subjects from the I and C groups progressed to dementia (Pearson chi square = 8.71, OR = 5.34, 95% CI 1.56-18.29). Logistic regression analysis controlled for baseline group differences in education and cognitive function suggested I group was associated with stable CDR (OR = 0.14, 95%CI = 0.03-0.71, p = 0.02). CONCLUSIONS: Our interim findings showed that Chinese style mind body (Tai Chi) exercise may offer specific benefits to cognition, potential clinical interests should be further explored with longer observation period.

Institutional risk factors for norovirus outbreaks in Hong Kong elderly homes: a retrospective cohort study.

BACKGROUND: Most of the institutional outbreaks of norovirus in Hong Kong occur in elderly homes, the proportion being 69% in 2006. Residents in elderly homes are a special population seriously affected by norovirus infections, it is necessary to investigate the risk factors of the norovirus outbreaks in Hong Kong elderly homes at the facility level. METHODS: A cohort of 748 elderly homes was followed up from January 2005 to December 2007; each elderly home was treated as one observation unit and the outcome event was the norovirus outbreak. Cox regression models were fitted to estimate the rate ratio (RR) and 95% confidence interval (CI) for the potential risk factors. RESULTS: A total of 276 norovirus outbreaks were confirmed during the study period; the outbreak rate was 12.2 (95% CI: 9.9-14.6) per 100 home-years; elderly homes with a larger capacity (RR = 1.4, 95% CI: 1.3-1.5 (per 30-resident increment)), a higher staff-to-resident ratio (RR = 1.2, 95% CI: 1.1-1.3 (per 1/30 increment) and better wheelchair accessibility (RR = 2.0, 95% CI: 1.3-3.2) were found to have an elevated norovirus outbreak rate in Hong Kong elderly homes; Elderly homes with partitions between beds had a lower rate of norovirus outbreaks (RR = 0.6, 95% CI: 0.4-0.8). CONCLUSIONS: Elderly home capacity, staff-to-resident ratio and wheelchair accessibility were risk factors for norovirus outbreaks in Hong Kong elderly homes. Partitions between beds were a protective factor of norovirus outbreaks. These results should be considered in the infection control in Hong Kong elderly homes.

Combined clinical and cognitive criteria to identify mild cognitive impairment in a southern Chinese community.

Mild Cognitive Impairment (MCI) is a recognized risk condition for clinical dementia. This paper attempted to explore the applicability of a combined cognitive and clinical approach to identify older Chinese adults at-risk of cognitive decline. Seven hundred forty randomly recruited community dwelling participants (aged 60 or over) were assessed at baseline and 2 years with Clinical Dementia Rating (CDR) and a cognitive battery. Baseline MCI groups were categorized by CDR-MCI, cognitive function (Cog-MCI), and a combined CDR-Cog approach. The cognitive approach adopted the Mayo clinic criteria. For the combined approach, nonamnestic MCI combined CDR 0.5 plus nonmemory cognitive deficits. The overall concordance between CDR and Cognitive test ratings were 65.3% (χ2 = 256.4, P<0.001, κ=0.44). With a combined approach, 424 (57%) participants were classified as normal. CDR-MCI group had higher cognitive scores compared with MCI groups by other criteria (1 way analysis of variance or ANOVA). At 2 years, the combined CDR-Cog MCI group identified all dementia (N=24) converters although group differences were not significant. Cognitive function and CDR identified participants potentially at-risk for furthermore decline, but exhibited some differences in detection profiles. A combined approach may be more practical in screening for MCI participants with diverse educational and cultural background.

Widened pulse pressure is a potential risk factor for significant cognitive impairment among community-dwelling Chinese younger old people.

Hypertension is a risk factor for dementia, but its exact role in contributing to dementia remains unknown. We conducted a community-based retrospective cohort study to examine the association of hypertension and widened pulse pressure (PP) with incident significant cognitive impairment (SCI) in Chinese older people in Hong Kong. A total of 1,925 subjects who were 65 years and older, ethnic Chinese, and community-living, with no history of cerebrovascular accidents or dementia, were recruited. Demographics, medical history, and physical parameters recorded at baseline were retrieved for analysis. Primary outcome was SCI developed in 6 years, which was defined by the presence of clinical dementia, scoring below the cutoff point on the Cantonese version of the Mini-Mental State Examination, and/or a global Clinical Dementia Rating of 1 to 3. Our data showed no difference in the point prevalence of pre-existing hypertension between subjects who remained cognitively stable and those who developed SCI (64.2% versus 65.8%; χ2 test, p = 0.68). However, subjects with incident SCI had a higher baseline PP (70 mmHg versus 66 mmHg; Mann-Whitney U-test, p = 0.03) and a decreasing trend in PP with time. Multiple logistic regression analysis showed that PP had a small but significant effect on the risk of SCI among the younger old subjects (OR = 1.02, p = 0.03). Our findings suggested that widened PP might be a risk factor for SCI among the younger old people. Further studies are needed to ascertain the association between hypertension and SCI in the Chinese older population and how widened PP contributes to SCI.

A 1-year randomized controlled trial comparing mind body exercise (Tai Chi) with stretching and toning exercise on cognitive function in older Chinese adults at risk of cognitive decline.

OBJECTIVES: To compare the effectiveness of Chinese-style mind-body exercise (24 forms simplified Tai Chi) versus stretching and toning exercise in the maintenance of cognitive abilities in Chinese elders at risk of cognitive decline. DESIGN: A 1-year single-blind cluster randomized controlled trial. SETTINGS: Community centers and residential homes for elders in Hong Kong. PARTICIPANTS: A total of 389 subjects at risk of cognitive decline (Clinical Dementia Rating, CDR 0.5 or amnestic-MCI) participated in an exercise intervention program. INTERVENTION: A total of 171 subjects were trained with Tai Chi (Intervention [I]) and 218 were trained with stretching and toning exercise (Control [C]). METHODS: Cognitive and functional performance were assessed at the baseline, and at 5, 9, and 12 months. Data were analyzed using multilevel mixed models. Primary outcomes included progression to clinical dementia as diagnosed by DSM-IV criteria, and change of cognitive and functional scores. Secondary outcomes included postural balance measured by the Berg Balance Scale neuropsychiatric and mood symptoms measured by the Neuropsychiatric Inventory, and Cornell Scale for Depression in Dementia. RESULTS: At 1 year, 92 (54%) and 169 (78%) participants of the I and C groups completed the intervention. Multilevel logistic regression with completers-only analyses controlled for baseline differences in education revealed that the I group had a trend for lower risk of developing dementia at 1 year (odds ratio 0.21, 95% CI 0.05-0.92, P = .04). The I group had better preservation of CDR sum of boxes scores than the C group in both intention-to-treat (P = .04) and completers-only analyses (P = .004). In completers-only analyses, the I group had greater improvement in delay recall (P = .05) and Cornell Scale for Depression in Dementia scores (P = .02). CONCLUSION: Regular exercise, especially mind-body exercise with integrated cognitive and motor coordination, may help with preservation of global ability in elders at risk of cognitive decline; however, logistics to promote long-term practice and optimize adherence needs to be revisited.

Promotion of seasonal influenza vaccination among staff in residential care homes for elderly in Hong Kong.

Annual influenza epidemics continue to cause worldwide morbidity, mortality and societal disruption, especially among the aged residents of residential care homes for the elderly (RCHEs). Vaccination remains the most effective measure to prevent influenza and its associated complications. The seasonal influenza vaccine uptake rates among RCHE staff were much lower than that among residents. In order to increase uptake of influenza vaccination among RCHE staff in Hong Kong, this study developed and evaluated amultimodal vaccine promotion program (VPP) based on identified factors affecting vaccination acceptance or refusal within the Hong Kong Chinese context. Vaccine acceptance was found to be significantly associated with belief in vaccine efficacy, duration of service, staff group and providing direct care to residents. The focus group study revealed that RCHE staff's belief in the efficacy and safety of the vaccine played a major role in vaccine acceptance. VPP effectiveness was evaluated with a cluster randomised controlled trial among RCHEs with staff vaccination rates below 50%. Compared with 2008/09, the 2009/10 mean staff vaccination rates increased significantly in both the intervention (39.4% to 59.6% (P < 0.001)) and control groups (36.3% to 47.6% (P = 0.008)). RCHE staff in the intervention group had a higher vaccination rate than in the control group (59.6% versus 47.6%, P = 0.072). This program reinforces the importance of a comprehensive and culturally sensitive approach to promote influenza vaccination for RCHE staff.