Development of a Three-Dimensional Carotid Ultrasound Image Segmentation Workflow for Improved Efficiency, Reproducibility and Accuracy in Measuring Vessel Wall and Plaque Volume and Thickness.

Automated segmentation of carotid lumen-intima boundary (LIB) and media-adventitia boundary (MAB) by deep convolutional neural networks (CNN) from three-dimensional ultrasound (3DUS) images has made assessment and monitoring of carotid atherosclerosis more efficient than manual segmentation. However, training of CNN still requires manual segmentation of LIB and MAB. Therefore, there is a need to improve the efficiency of manual segmentation and develop strategies to improve segmentation accuracy by the CNN for serial monitoring of carotid atherosclerosis. One strategy to reduce segmentation time is to increase the interslice distance (ISD) between segmented axial slices of a 3DUS image while maintaining the segmentation reliability. We, for the first time, investigated the effect of ISD on the reproducibility of MAB and LIB segmentations. The intra-observer reproducibility of LIB and MAB segmentations at ISDs of 1 mm and 2 mm was not statistically significantly different, whereas the reproducibility at ISD = 3 mm was statistically lower. Therefore, we conclude that segmentation with an ISD of 2 mm provides sufficient reliability for CNN training. We further proposed training the CNN by the baseline images of the entire cohort of patients for automatic segmentation of the follow-up images acquired for the same cohort. We validated that segmentation with this time-based partitioning approach is more accurate than that produced by patient-based partitioning, especially at the carotid bifurcation. This study forms the basis for an efficient, reproducible, and accurate 3DUS workflow for serial monitoring of carotid atherosclerosis useful in risk stratification of cardiovascular events and in evaluating the efficacy of new treatments.

Willingness to Purchase Hypothetical Private Long-Term Care Insurance Plans in a Super-ageing Society: Evidence from Hong Kong.

Despite the soaring demand for long-term care (LTC) services in aging societies, dedicated risk-pooling mechanisms are largely absent. Private insurance has been advocated but the market remains small. This study seeks to unravel this paradox through an empirical study in Hong Kong, a super-aging society. We analyzed middle-aged individuals' willingness to purchase hypothetical private LTC insurance plans derived from a discrete choice experiment. A survey was conducted in 2020 and sampled 1,105 respondents. We noted a fairly encouraging level of acceptance but also found clear barriers toward potential purchase. The desire for self-sufficiency and preference for formal care powerfully increased individuals' interest. Cognitive difficulty, habitual adherence to out-of-pocket payment, and unfamiliarity with the LTC insurance market reduced such interest. We explained the results with reference to the changing social dynamics and drew policy implications for LTC reforms in Hong Kong and beyond.

Mini-review: Recent advances in post-translational modification site prediction based on deep learning.

Post-translational modifications (PTMs) are closely linked to numerous diseases, playing a significant role in regulating protein structures, activities, and functions. Therefore, the identification of PTMs is crucial for understanding the mechanisms of cell biology and diseases therapy. Compared to traditional machine learning methods, the deep learning approaches for PTM prediction provide accurate and rapid screening, guiding the downstream wet experiments to leverage the screened information for focused studies. In this paper, we reviewed the recent works in deep learning to identify phosphorylation, acetylation, ubiquitination, and other PTM types. In addition, we summarized PTM databases and discussed future directions with critical insights.

Preferences for private long-term care insurance products in a super-ageing society: A discrete choice experiment in Hong Kong.

There is a stark contrast between rising long-term care (LTC) demands and limited financing capacity in many ageing societies. Despite the theoretical potential of private insurance in LTC financing reforms, the reality is that the market remains remarkably underdeveloped. This study adopts a novel two-phase approach to quantitatively examine the market demand for private long-term care insurance (LTCI) in Hong Kong, one of the world's super-ageing societies. In order to examine people's preferences regarding private LTCI in Hong Kong, which has been exploring alternative LTC financing mechanisms to relieve the overburdened public system, we conducted a discrete choice experiment (DCE) in 2019 to elicit the preferences of a representative sample of 410 middle-aged adults. At first, we used data from the US National Longterm Care Survey to perform an actuarial projection for Hong Kong. In the first phase, we computed the indicative premiums based on various attributes of hypothetical private LTCI products. Undertaken in the second phase and using two econometric techniques, the DCE suggested that the most preferred hypothetical LTCI product in Hong Kong was associated with the following features: 1) a monthly benefit level of HK$20,000 or HK$25,000, 2) 3% inflation protection, and 3) 15 years of contribution. These attributes led to a monthly premium of HK$1237 (US$160)/HK$1546 (US$200) for men and HK$2150 (US$278)/HK$2687 (US$348) for women. Furthermore, we also found that the preference for LTCI products varied across people with different socioeconomic and health characteristics. These insights could inform initial market segmentation, LTCI product design, and targeted marketing in the future. This paper concludes with cautious optimism regarding the market demand for private LTCI in Hong Kong, and recommends concrete policy instruments to nurture the LTCI market, including information campaign, premium subsidies, and tax benefits.

Consumer Preferences and Demand for Annuities: Evidence From Hong Kong.

Retirees without annuities in Hong Kong confront longevity and investment risks. Despite these risks, there is very limited uptake of annuities. This study identifies product and consumer characteristics that are associated with the demand for annuities in Hong Kong. We conduct a discrete choice experiment and distribute a consumer survey among two independent representative samples of workers aged between 40 and 64. Results suggest that a fixed monthly income and a 10-year guarantee period are two significant product characteristics, while a bequest motive, being married, and an understanding of the annuity are consumer characteristics that are associated with the demand for annuities. Being presented the optimal hypothetical annuity product, approximately one-third of middle-aged workers choose to annuitize their retirement savings. The findings and methods of this study can be applied for designing annuity products in other contexts.

Social and psychological barriers to private retirement savings in Hong Kong.

Using a phone survey conducted among Hong Kong workers, we examined the association of institutional, social, and psychological factors with engagement in both private retirement savings and the total amount of savings. Alarmingly, this study demonstrates that approximately 42% of Hong Kong workers do not save privately for their retirement. We found that age, education, number of children, support from spouse and friends, social regulation, perceived financial knowledge, and financial management capacity are associated with engagement in private retirement savings. Among those who saved, age, education, perceived financial knowledge, and financial management capacity are related to the amount of savings. Measures that could increase the social support for retirement savings as well as enhance their financial knowledge and management ability should be developed and implemented so that more workers engage in private retirement savings. A promising policy option for the Hong Kong government is to offer a tax incentive to promote additional savings for old-age income protection.

Elucidation and short-term forecasting of microcystin concentrations in Lake Suwa (Japan) by means of artificial neural networks and evolutionary algorithms.

Non-supervised artificial neural networks (ANN) and hybrid evolutionary algorithms (EA) were applied to analyse and model 12 years of limnological time-series data of the shallow hypertrophic Lake Suwa in Japan. The results have improved understanding of relationships between changing microcystin concentrations, Microcystis species abundances and annual rainfall intensity. The data analysis by non-supervised ANN revealed that total Microcystis abundance and extra-cellular microcystin concentrations in typical dry years are much higher than those in typical wet years. It also showed that high microcystin concentrations in dry years coincided with the dominance of the toxic Microcystis viridis whilst in typical wet years non-toxic Microcystis ichthyoblabe were dominant. Hybrid EA were used to discover rule sets to explain and forecast the occurrence of high microcystin concentrations in relation to water quality and climate conditions. The results facilitated early warning by 3-days-ahead forecasting of microcystin concentrations based on limnological and meteorological input data, achieving an r(2)=0.74 for testing.

Hong Kong's health spending projections through 2033.

OBJECTIVE: To derive actuarial projection estimates of Hong Kong's total domestic health expenditure to the year 2033. METHODS: Disaggregating health expenditure by age, sex, unit cost and utilisation level, we estimated future health spending by projecting utilisation (by public/private, inpatient/outpatient care) to reflect demographic changes and associated increase in demand (from higher expectations and greater intensity of care), and then multiplying such by the projected unit costs (incorporating the impact of key cost drivers such as public expectations, technological changes and potential productivity gains) to obtain total expenditure estimates. RESULTS: The model was most sensitive to the excess health care price inflation rate, i.e. the annual price/cost growth of medical goods and services over and above per capita GDP growth. Population ageing and growth per se, without taking into account related technologic innovation for chronic conditions that particularly afflict older adults, contribute relatively little to overall spending growth. Given the model assumptions, it is possible to limit total health spending to below 10% of GDP by 2033, where the public share would gradually decline from the current 57% to between 46% and 49%. CONCLUSIONS: Expenditure control through global budgeting, technology assessment and demand-side constraints should be considered although their effectiveness remains inconclusive.

Moral hazard or realised access to care? Empirical observations in Hong Kong.

We examined for the presence of moral hazard among those covered by medical benefits or insurance schemes, whether provided for by employers or privately purchased and stratified by health care provider sector in Hong Kong. Data for this study were derived from the 2002 Thematic Household Survey, covering 24,610 non-institutional residents aged 15 and over, representing 5,353,666 persons after applying population weights. Zero-inflated Poisson or negative binomial models were constructed to examine the association between predisposing, need and enabling factors with inpatient and outpatient utilisation patterns as per Andersen's health behavioural framework. Individuals with insurance or medical benefits were more likely to have been ever admitted in the previous year but did not incur more bed-days. Similarly, those who were covered by insurance or medical benefits had a higher probability of ever visiting a doctor in the previous month but not consuming more episodes. These findings were consistent across the public and private sectors. We propose that our observations mostly reflected realised access that met genuine health need rather than inappropriate overuse of services. A supply-driven public sector and high out-of-pocket co-payments for private services likely explained these findings.

The ecology of health care in Hong Kong.

To better understand the distribution of resources and health care consumption patterns in different geo-ethnic and socio-economic settings, we sought to describe the patterns of illness, care-seeking behavior and health services utilization in Hong Kong compared to the US and UK. Data were derived from the 2002 Hong Kong Thematic Household Survey covering 31,762 non-institutional and institutional residents, representing 6,504,255 persons after applying population weights. Of 1000 individuals during a 1-month period, 567 reported symptoms, 512 of whom considered seeking health care. Four hundred and forty persons visited western allopathic medical practitioners, with 372 (84.5%) in primary care and 68 (15.5%) in specialty care. There were 54 visits to traditional Chinese medical practitioners and 16 emergency room episodes. Seven individuals were hospitalized in community hospitals and on average one in 1000 were admitted to a tertiary medical center. Ninety out of the 567 who experienced symptoms undertook self-management strategies, which included over-the-counter western allopathic medications (n=54) or traditional Chinese remedies (n=14) or both (n=2), dietary modification (n=1) and rest (n=15). We have mapped the ecology of health care in Hong Kong. Monthly prevalence estimates were remarkably similar to US figures for hospital-based events, whereas there was evidence of apparent, substantial "over-consumption" of ambulatory, community-based care. Our results also indicate that the local community's care-seeking orientation still very much favors western allopathic medicine over traditional Chinese therapy, at least for acute illness episodes.

Multiple comparisons with a control in families with both one-sided and two-sided hypotheses.

Comparing several treatments with a control is a common objective of clinical studies. However, existing procedures mainly deal with particular families of inferences in which all hypotheses are either one- or two-sided. In this article, we seek to develop a procedure which copes with a more general testing environment in which the family of inferences is composed of a mixture of one- and two-sided hypotheses. The proposed procedure provides a more flexible and powerful tool than the existing method. The superiority of this method is also substantiated by a simulation study of average power. Selected critical values are tabulated for the implementation of the proposed procedure. Finally, we provide an illustrative example with sample data extracted from a medical experiment.

Multiple testing to establish superiority/equivalence of a new treatment compared with k standard treatments for unbalanced designs.

In clinical studies, multiple superiority/equivalence testing procedures can be applied to classify a new treatment as superior, equivalent (same therapeutic effect), or inferior to each set of standard treatments. Previous stepwise approaches (Dunnett and Tamhane, 1997, Statistics in Medicine16, 2489-2506; Kwong, 2001, Journal of Statistical Planning and Inference 97, 359-366) are only appropriate for balanced designs. Unfortunately, the construction of similar tests for unbalanced designs is far more complex, with two major difficulties: (i) the ordering of test statistics for superiority may not be the same as the ordering of test statistics for equivalence; and (ii) the correlation structure of the test statistics is not equi-correlated but product-correlated. In this article, we seek to develop a two-stage testing procedure for unbalanced designs, which are very popular in clinical experiments. This procedure is a combination of step-up and single-step testing procedures, while the familywise error rate is proved to be controlled at a designated level. Furthermore, a simulation study is conducted to compare the average powers of the proposed procedure to those of the single-step procedure. In addition, a clinical example is provided to illustrate the application of the new procedure.