Ks Chan

Prevalence of Depression and Its Correlates in Hong Kong's Chinese Older Adults

OBJECTIVE Because of the rapid aging of the population and inconsistent findings of previous epidemiological studies in Hong Kong, a prevalence study of depression among older adults was timely. The authors assessed the prevalence of depression among older adults and identified factors associated with it. METHODS The authors interviewed a random representative sample of 917 community-dwelling Chinese adults age 60 and over. The 15-item Chinese Geriatric Depression Scale with a cutoff of > or = 8 was used to identify clinically significant depression in the older adults. RESULTS The authors found that 11.0% and 14.5% of older Chinese men and women, respectively, scored above the cutoff, a prevalence rate similar to those found in other countries, including the United States, England, and Finland. Factors that were associated with an increased likelihood of depression among older adults included poor self-rated health, long-term pain, vision problems, higher level of impairment in activities of daily living, residing in Hong Kong less than 20 years, financial strain, and having less social support. CONCLUSIONS The prevalence rate of depression among older Chinese adults in Hong Kong is more or less similar to rates found in Western countries. The data suggest that older adults who receive less social support are more likely to be depressed.

Psychosocial risk factors associated with falls among Chinese community-dwelling older adults in Hong Kong.

This study examined the relationship between psychosocial factors and falls among community-dwelling older adults in the Hong Kong Special Administrative Region of China. The study included 1573 adults aged 60 or above who lived at home and who were applying for long-term care services. These participants were part of a large cross-sectional survey carried out between 2003 and 2004 in which they completed the Hong Kong Chinese version of the Resident Assessment Instrument-Home Care (RAI-HC) assessment. Of those persons who were surveyed, 516 (32.8%, 95% CI 30.5% to 35.2%) had fallen in the previous 90 days. Bivariate analyses showed that five psychosocial factors (depressive symptoms, fear of falling, a decline in social activities, the number of hours of informal care support during weekdays and living alone) were significantly associated with falls (P < 0.05). Logistic regression analysis showed living alone (odds ratio (OR) = 0.62; 95% CI 0.44 to 0.86) was the only psychosocial factor significantly associated with falls, after adjusting for the known significant factors related to falls. It was also found that more elders who lived with others had environmental hazards than those who lived alone (71.0% vs 29.0%, chi2 = 4.80, P = 0.028). These findings suggested that living with others may not be as safe as we assume. Interventions to increase awareness of home safety and to seek co-operation with family members in falls prevention are recommended. Fall preventive strategies should be educated to family members who are living with frail older adults. On the other hand, Chinese older adults who live alone often receive support from relatives or friends. Social support seems to be crucial to prevent them from falls and this measure is recommended to be continued in the community.

Validation of Self-Image of Aging Scale for Chinese Elders

Researchers are increasingly interested in the “image of aging” concept. Models on the image of aging abound, but few have rigorously tested measures that are culturally sensitive and domain-specific. This study first translates Levy et al.‘s (2004) Image of Aging Scale into the Chinese language and revises it into the Chinese Version of the Self-Image of Aging Scale (SIAS-C). Based on the results of a survey of 445 elderly people in Wuhan-China, it then reports the factorial structure of SIAS-C and some of its psychometric properties. Confirmatory factor analysis (CFA) supports a conceptually meaningful five-factor model, as suggested in an exploratory factor analysis (EFA). The 14-item SIAS-C vindicates an acceptable level of internal consistency and test-retest reliability. Its criteria-referenced validity is demonstrated by its correlation with several criteria in expected directions. In conclusion, the SIAS-C is a psychometrically sound instrument which is recommended for use among Chinese older people.

Care Management Service and Falls Prevention: A Case-Control Study in a Chinese Population

Objective: This study evaluates the effect of a care management service (CMS) on falls in older adults. Method: This is a retrospective case-control study with 78 CMS recipients as the case group who received CMS and another 312 community-dwelling frail elders as the control group.The groups were matched by age, gender, activity of daily living, cognitive impairment, and unsteady gait. Thus they were comparable in characteristics and frailty. Results: Among the 390 participants, 89 older adults (23.0%) had falls in the 90 days prior to the survey. After controlling for the identified risk factors for falls, the odds ratio of CMS was 0.27 (95% confidence interval = 0.110-0.663, p < .01). Discussion: These findings indicate that CMS recipients have a lower chance for falls compared to their counterparts. The two features of CMS (comprehensive assessment and multidisciplinary actions to reduce fall risks) are discussed.

A unified approach for estimating population size in capture-recapture studies with arbitrary removals

A unified approach is suggested to estimate the population size for a closed population in discrete time. Individuals can be removed after capture at any time during the experiment. The usual recapture and removal experimentsare shown to be particular cases of the general formulation. The capture probability is assumed to have a logistic function that depends on individual covariates and can be time dependent. The unified approach involves a two-step procedure. A conditional likelihood function is used to estimate the covariates coefficients and a Horvitz-Thompson type estimator to estimate the population size. The asymptotic and small-sample properties of the resulting estimators are in vestigated. A real example is given.

Estimating the number of faults: efficiency of removal, recapture, and seeding

Various experimental designs for estimating the number of faults in a system are studied including: (1) removal of each fault as it is detected; (2) marking of each fault as it is detected; and (3) introduction of a known number of faults into the system followed by (1) or (2). A unified framework is developed for comparing these designs; it also produces simplified estimators having high efficiency relative to maximum likelihood estimators. The designs are compared in terms of: (1) statistical accuracy; and (2) the number of failures that need to occur to achieve a given accuracy. On the basis of these comparisons, some general recommendations are made on the level of seeding as well as the choice of removal or recapture designs. When the testing effort is sufficient so that roughly two thirds of the faults are detected, the removal-design is preferred over the recapture-design, and there are no gains from seeding. However, this conclusion depends on assigning unit cost to all fault detections, which might not always be reasonable.

A comparison of recapture, removal and resighting designs for population size estimation

We study various experimental designs for estimating the size of a closed population into which a known number, possibly zero, of distinguishable individuals are initially planted. These designs include (i) removal of each individual as it is detected, (ii) marking of each individual as it is detected and (iii) resighting individuals without capturing or removing them. We develop estimating equations for the unknown parameters, and compare the three designs by the asymptotic accuracy of the most efficient estimators they admit. Simulation results are also reported, comparing the three designs in small samples.