Biomedical subjects

Andy H Lee

Publications and source records attributed to Andy H Lee.

72 records · Page 4Linked to original sources

PubMed2003

Quality of life for adolescents: assessing measurement properties using structural equation modelling.

Assessments for quality of life (QOL) of the adolescent have received relatively little attention in the literature. Although there is no consensus on the definition of adolescent QOL and what aspects should be measured, it is generally accepted that QOL is a multidimensional construct. The objective of this study is to determine the measurement properties of the latent factors underlying adolescent QOL based on a second-order confirmatory factor analysis (CFA). A recursive structural equation model (SEM) is then proposed to determine the direction and magnitude of the interdependent effects among the latent factors. The questionnaire used was the Quality of Life Profile-Adolescent Version (QOLPAV). A sample of 363 adolescents was recruited from 20 secondary schools in Perth, Australia. The second-order CFA suggested that adolescent QOL may be measured by five underlying constructs namely social, environment, psychological, health, and opportunities for growth. The interdependent relations among these constructs identified the environment factor as primary, exerting both direct and indirect effects on the other four factors.

Adolescent↗

PubMed2003

Emergency presentations to Northern Territory public hospitals: demand and access analysis.

This study aims to quantify trends in emergency presentations to Northern Territory (NT) public hospitals over the past five years with respect to demand and access. Retrospective analysis was undertaken on data extracted from the NT Module of Caresys and the Hospital Morbidity Data System. There has been a 4.6% decrease in presentations to the five public hospitals between 1996 and 2001 compared to a 9.4% growth in the population. Despite the apparent decline in total presentations, the acuity of patients has increased dramatically over the same period. Access analysis of presentations seen within the recommended triage time revealed considerable variability, especially for triage categories 2, 3 and 4. The access block problem, discrepancies in recorded waiting time and irregularities among the regional hospitals within the triage system have also been identified. Recommendations including improved access to inpatient beds and admission to wards were developed in response to the changing role of the emergency department.

Appointments and Schedules↗

PubMed2003

Factors influencing residents' satisfaction in residential aged care.

PURPOSE: The aim of this study was to identify the important factors influencing residents' satisfaction in residential aged care and to provide a better understanding of their interrelationships. DESIGN AND METHODS: A cross-sectional survey design was used to collect the required information, including resident satisfaction, resident dependency levels, and staff satisfaction. A stratified random sampling approach was utilized to select facilities. All residents satisfying the selection criteria (i.e., understand English, be sufficient cognitive competence, have a sufficient energy level to participate in the survey, and live in the facility for more than 4 weeks) and all care staff were invited to participate. A total of 996 residents and 895 staff from 62 facilities (36 hostels and 26 nursing homes) provided the required data. Structural equation modeling was used to examine the interrelationships among three sets of contributing factors, related to the facility, staff and residents, and resident satisfaction components, separately for nursing home and hostel residents. RESULTS: Overall fits of both nursing home and hostel models were satisfactory. This study has revealed that staff satisfaction plays a crucial and central role in determining resident satisfaction in nursing homes, whereas it has less impact in hostels. The provision of more care hours has only a small, yet positive, impact on resident satisfaction. Larger facility size has a negative impact on resident involvement. Older residents were found to be more satisfied with staff care. IMPLICATIONS: The results provide a comprehensive understanding of what influences resident satisfaction. By accounting for important factors identified by residents, a resident-focused care model can be developed and implemented, leading to better service for aged care residents.

Aged↗

PubMed2003

Analyzing hospital length of stay: mean or median regression?

BACKGROUND: Length of stay (LOS) is an important measure of hospital activity and health care utilization, but its empirical distribution is often positively skewed. OBJECTIVE: This study reviews the mean and median regression approaches for analyzing LOS, which have implications for service planning, resource allocation, and bed utilization. METHODS: The two approaches are applied to analyze hospital discharge data on cesarean delivery. Both models adjust for patient and health-related characteristics, and for the dependency of LOS outcomes nested within hospitals. The estimation methods are also compared in a simulation study. RESULTS: For the empirical application, the mean regression results are somewhat sensitive to the magnitude of trimming chosen. The identified factors from median regression, namely number of diagnoses, number of procedures, and payment classification, are robust to high-LOS outliers. The simulation experiment shows that median regression can outperform mean regression even when the response variable is moderately positively skewed. CONCLUSION: Median regression appears to be a suitable alternative to analyze the clustered and positively skewed LOS, without transforming and trimming the data arbitrarily.

Cesarean Section↗

PubMed2003

Minimum Hellinger distance estimation for finite mixtures of Poisson regression models and its applications.

Minimum Hellinger distance estimation (MHDE) has been shown to discount anomalous data points in a smooth manner with first-order efficiency for a correctly specified model. An estimation approach is proposed for finite mixtures of Poisson regression models based on MHDE. Evidence from Monte Carlo simulations suggests that MHDE is a viable alternative to the maximum likelihood estimator when the mixture components are not well separated or the model parameters are near zero. Biometrical applications also illustrate the practical usefulness of the MHDE method.

Algorithms↗

PubMed2003

Adolescent quality of life: a school-based cohort study in Western Australia.

BACKGROUND: Quality of life (QOL) has received increasing attention in pediatrics medicine recently. Improving QOL is the primary justification for many interventions, medications and therapies. The present study is a school-based longitudinal study which aims to investigate the factors affecting QOL of adolescents in Western Australia over a 6-month period. METHODS: A generic self-reported questionnaire was administered twice to participants from 20 schools in Perth at 6 months apart. In addition to QOL scores and physical health status, demographic and other information was also collected. For the cohort of 363 students who participated in the initial survey, 300 of them completed the second questionnaire. RESULTS: A significant change in QOL score between baseline and 6 months was observed. Results from fitting a hierarchical mixed regression model indicated that 55% of the variation in QOL was due to differences between individuals, and was significantly associated with age, control, opportunities and perceptions of physical health, while the remaining variance component could be attributed to within-individual changes. Improved control and opportunities appeared to have a significant positive impact on QOL, whereas increasing age and deterioration in physical health had the opposite effect. CONCLUSIONS: The hierarchical regression analysis has enabled valid inferences to be made based on the observed longitudinal data. Perceptions of physical health, age, control and opportunities available are related to adolescent QOL. The findings have implications on evidence-based practices and childhood health issues.

Adolescent↗

PubMed2003

A cohort study of drink-driving motor vehicle crashes and alcohol-related diseases.

OBJECTIVES: To elicit whether drivers involved in alcohol-related motor vehicle crashes are more likely to have future alcohol-related hospital admissions. METHOD: A population-based cohort study of 3,286 drivers involved in a motor vehicle crash between 1988 and 1992 were followed over an eight to 13-year period. RESULTS: The findings from the study suggest a twofold increased risk associated with an alcohol-related motor vehicle crash and future alcohol-related hospital admission. The average time between an alcohol-related motor vehicle crash and future alcohol-related hospital admission was 12 years. Men and indigenous Australian drivers were more likely to have a future alcohol-related hospital admission. CONCLUSION: It is evident from this study that drink-driving resulting in a motor vehicle crash and hospitalisation could be considered an indicator of a less overt problem of alcohol dependency. IMPLICATIONS: It is important that penalties for drink-driving go beyond merely punitive action and provide rehabilitation.

Accidents, Traffic↗

PubMed2002

A hierarchical Poisson mixture regression model to analyse maternity length of hospital stay.

Inpatient length of stay (LOS) is often considered as a proxy of hospital resource consumption. Using statewide obstetrical delivery data, a two-component Poisson mixture model provides a reasonable fit to the heterogeneous LOS distribution. Adopting the generalized linear mixed model (GLMM) approach, random effects are introduced to the two-component Poisson mixture regression model to account for the inherent correlation of patients clustered within hospitals. An EM algorithm is developed for the joint estimation of regression coefficients and variance component parameters. Related diagnostic measures for assessing model adequacy are derived. When applying the method to analyse maternity LOS, appropriate risk factors for the short-stay and long-stay subgroups can be identified from the respective Poisson components. In addition, predicted random hospital effects enable the comparison of relative efficiencies among hospitals after adjustment for patient case-mix and health provision characteristics.

Adult↗

PubMed2002

Modeling young driver motor vehicle crashes: data with extra zeros.

Much of the data collected on motor vehicle crashes is count data. The standard Poisson regression approach used to model this type of data does not take into account the fact there are few crash events and hence, many observed zeros. In this paper, we applied the zero-inflated Poisson (ZIP) model (which adjusts for the many observed zeros) and the negative binomial (NB) model to analyze young driver motor vehicle crashes. The results of the ZIP regression model are comparable to those from fitting a NB regression model for general over-dispersion. The findings highlight that driver confidence/adventurousness and the frequency of driving prior to licensing are significant predictors of crash outcome in the first 12 months of driving. We encourage researchers, when analyzing motor vehicle crash data, to consider the empirical frequency distribution first and to apply the ZIP and NB models in the presence of extra zeros due, for example, to under-reporting.

Accidents, Traffic↗

PubMed2002

A zero-inflated Poisson mixed model to analyze diagnosis related groups with majority of same-day hospital stays.

With increasing trend of same-day procedures and operations performed for hospital admissions, it is important to analyze those Diagnosis Related Groups (DRGs) consisting of mainly same-day separations. A zero-inflated Poisson (ZIP) mixed model is presented to identify health- and patient-related characteristics associated with length of stay (LOS) and to model variations in LOS within such DRGs. Random effects are introduced to account for inter-hospital variations and the dependence of clustered LOS observations via the generalized linear mixed models (GLMM) approach. Parameter estimation is achieved by maximizing an appropriate log-likelihood function using the EM algorithm to obtain approximate residual maximum likelihood (REML) estimates. An S-Plus macro is developed to provide a unified ZIP modeling approach. The determination of pertinent factors would benefit hospital administrators and clinicians to manage LOS and expenditures efficiently.

Algorithms↗

PubMed2002

Dietary patterns and nutrient intake of adult women in south-east China: a nutrition study in Zhejiang province.

This study documents the dietary patterns and nutrient intake of 652 adult women living in south-east China. Compared with data from previous national surveys and other nutrition studies in China, the results show different dietary patterns. The major differences include a greater consumption of vegetables, fruits and animal foods, but a lower consumption of cereal and tuber foods. The mean daily nutrient intakes of the urban women met the Chinese recommended dietary allowances. However, the situation was different in rural areas, where women had lower mean intakes of vitamins and minerals. There were also significant differences in dietary pattern and food consumption between these two groups of women. Further improvements in dietary intake for those residing in the south-east rural areas of China are needed.

Adolescent↗

PubMed2002

Resident satisfaction and its components in residential aged care.

PURPOSE: The purpose of this study was to assess the direction and magnitude of the effects among the components of resident satisfaction in residential aged care and to examine if the relationships among satisfaction components vary according to facility type (i.e., nursing home and hostel). Briefly, a hostel is a low-care facility in which residents are more independent and receive personal but not nursing care. DESIGN AND METHODS: A cross-sectional survey design was adopted to collect the required information, and a stratified random sampling approach was used to select facilities. Structural equation modeling was used to examine relationships among satisfaction components in a sample of 394 nursing home and 752 hostel residents. RESULTS: The results indicate that satisfaction with staff care has a moderate and positive effect on all other aspects of resident satisfaction. The relationships among satisfaction components are different for nursing home and hostel residents. IMPLICATIONS: The findings lead to an improved understanding of the interrelationship among resident satisfaction components, which has important implications for improving quality outcomes (e.g., resident satisfaction) through appropriate intervention (e.g., enhancing staff care).

Aged↗

PubMed2002

Measuring job satisfaction in residential aged care.

BACKGROUND: Staff satisfaction has received increasing recognition as an important factor influencing service quality and in particular the quality of residents' lives in residential aged care facilities, where staff typically have a long-term and close relationship with residents. Consequently, a valid and reliable instrument is required to assess staff satisfaction in this particular context. OBJECTIVE: This paper aims to assess the factor structure, reliability, and validity of the Measure of Job Satisfaction (MJS) instrument when used in residential aged care facilities. DESIGN: A cross-sectional survey design was used to collect the required information, and a stratified random sampling method was utilized to select facilities. Exploratory and confirmatory factor analyses were conducted to assess the factor structure of staff satisfaction via the MJS. SETTING: Both high and low care residential aged care facilities in Western Australia. STUDY PARTICIPANTS: Nine hundred and eighty-three staff (including the Director of Nursing, manager, registered nurses, enrolled nurses, nursing assistants, and therapists) in 70 residential aged care facilities. RESULTS: An acceptable five-factor (22-item) measurement model was derived. The Cronbach's alpha reliability levels range from 0.86 to 0.95. Convergent and discriminant validity are also satisfactory. CONCLUSION: This investigation has confirmed that a modified MJS is a reliable and valid instrument for assessing staff satisfaction in residential aged care settings.

Aged↗

PubMed2002

Staff satisfaction and its components in residential aged care.

OBJECTIVE: The purpose of this study was to assess the direction and magnitude of the effects among the components of staff satisfaction in residential aged care and to examine whether the relationships among satisfaction components vary according to facility type (i.e. nursing homes and hostels). A hostel is a low care facility in which residents are more independent, have a lower level of care needs, and receive personal but not nursing care. DESIGN: A cross-sectional survey design was adopted to collect the required information, and a stratified random sampling approach was utilized to select facilities. Structural equation modeling was used to examine relationships among satisfaction components. SETTING: Seventy residential aged care facilities in Western Australia. STUDY PARTICIPANTS: The sample includes 610 nursing home and 373 hostel care staff. RESULTS: The relationships among satisfaction components are different for nursing home and hostel staff. Professional support is found to have a strong and positive effect on all other aspects of staff satisfaction. CONCLUSION: The findings lead to an improved understanding of the interrelationship among staff satisfaction components, which has important implications through enhancing professional support. This needs to be recognized and emphasized by managers, care providers, and policy makers so as to maintain stable personnel and continuity of care.

Aged↗

PubMed2002

Effectiveness of a workplace risk assessment team in reducing the rate, cost, and duration of occupational injury.

This study evaluated the effectiveness of a consultative workplace risk assessment team in reducing the rate and severity of injury among cleaners within a 600-bed hospital. Cohorts of Cleaning Services and Orderly Services staff ever employed within both a 4-year preintervention and a 3-year postintervention period were assigned to the intervention and comparison groups, respectively. The date, compensation claims' cost, and hours lost from work were obtained for each injury during the study period. Age, gender, work experience, and hours worked were ascertained for every subject whether injured or not. Reductions of two thirds in injury rate, 73% in cost rate, and 43% in duration rate were evident in the intervention group. In comparison, the orderlies experienced a postintervention increase in all three rates. The success of the workplace risk assessment team intervention supports the adoption of a participatory approach to reducing the rate and consequence of workplace injury.

Accidents, Occupational↗

PubMed2002

Tea consumption and ovarian cancer risk: a case-control study in China.

To investigate whether tea consumption has an etiological association with ovarian cancer, a case-control study was conducted in China during 1999-2000. The cases were 254 patients with histologically confirmed epithelial ovarian cancer. The 652 controls comprised 340 hospital visitors, 261 non-neoplasm hospital outpatients, and 51 women recruited from the community. Information on the frequency, type, and duration of tea consumption was collected by personal interview using a validated questionnaire. The risk of ovarian cancer for tea consumption was assessed using adjusted odds ratios based on multivariate logistic regression analysis, accounting for confounding demographic, lifestyle, and familial factors including hormonal status and family ovarian cancer. The ovarian cancer risk declined with increasing frequency and duration of overall tea consumption. The adjusted odds ratio was 0.39 for those drinking tea daily and 0.23 for those drinking tea for >30 years, compared with nontea drinkers. The dose response relationships were significant, and the inverse association with ovarian cancer was observed for green tea consumption. We concluded that increasing frequency and duration of tea drinking, especially green tea, can reduce the risk of ovarian cancer. However, the protective effects of black tea and Oolong tea need to be additionally investigated.

Adult↗

PubMedDate not supplied

Validation of a driving simulator by measuring the visual attention skill of older adult drivers.

OBJECTIVE: The purpose of this study was to validate a laboratory-based driving simulator as an off-road screening tool for older adult drivers by measuring their visual attention skill, and to determine how the visual attention skill changes across time in a 45-minute simulated driving test. METHOD: One hundred and twenty-nine community-dwelling older drivers volunteered to take part in the study. A range of driving scenarios was devised and implemented in a simulator setting to assess the driving skills of the participants. Visual attention skill, an important contributing factor to motor vehicle crashes, was assessed by the participant's reaction times to a sequence of 14 visual stimuli during the primary task of sustained driving. Repeated measures of analysis of variance (ANOVA) were undertaken to determine the effects of age and gender on the visual attention skill. Trend analysis was performed to investigate how repeated exposures to the visual stimulus affected the reaction time. RESULTS: The visual attention skill of older drivers was found to decline with age (F(1,126)) = 42.52, p value = 0.002), whereas the effect of gender was not significant. Participants increased their speed of reaction times for the first half of the testing then slowed down during the second half. CONCLUSION: That visual attention skill declined with age was consistent with the literature, and validated the driving simulator as an effective screening tool for older adult drivers. With rapid advancements in computer technology, the driving simulator will likely play an important role in assisting occupational therapists with off-road assessment of older drivers.

Aged↗

PubMedDate not supplied

Identifying older drivers at risk of traffic violations by using a driving simulator: a 3-year longitudinal study.

OBJECTIVES: This prospective longitudinal study aims to determine which simulated driving tasks of a personal computer (PC)-based driving simulator can be used to identify problematic older drivers, using their 3-year driver violation points record as the outcome measure. METHODS: A total of 129 urban community-dwelling older drivers volunteered to participate in the study. Using a driving simulator, specific driving tasks were devised to test the performance of older drivers. Their officially recorded driver violation points were retrieved immediately after the simulated driving assessment and thereafter for the following 2 years. Self-reported driving records were also collected during the same period. Hierarchical Poisson regression analysis, adjusting for gender, age, and driving exposure (hours of driving per week), was then undertaken to determine those driving tasks that affected the frequency of traffic violations. RESULTS: All participants incurred at least one driver violation point during the 3-year period. The simulated driving tasks found to be significantly associated with the incidence of traffic violations were working memory and use of indicator. CONCLUSIONS: This longitudinal study demonstrated that the driving simulator was able to identify unsafe older drivers at risk of traffic violations if appropriate simulated driving tasks were used. Such a screening tool should be adopted prior to administering a more detailed but expensive road test.

Accidents, Traffic↗