Wai-Man Liu

Body Mass Index More Than 45 kg/m2 as a Cutoff Point Is Associated With Dramatically Increased Postoperative Complications in Total Knee Arthroplasty and Total Hip Arthroplasty

BACKGROUND Higher body mass index (BMI) has been associated with postoperative complications in total knee arthroplasty (TKA) and total hip arthroplasty (THA). However, the association of incremental increases of BMI and its effects on postoperative complications has not been well studied. We hypothesize that there is a BMI cutoff at which there is a significant increase of the risk of postoperative complications. METHODS We studied the American College of Surgeons National Surgical Quality Improvement Program from 2006 to 2013. The final cohort included 77,785 primary TKA and 49,475 primary THA subjects, respectively. Patients were separated into 7 groups based on BMI (18.5-24.9 kg/m(2), 25.0-29.9 kg/m(2), 30.0-34.9 kg/m(2), 35.0-39.9 kg/m(2), 40.0-44.9 kg/m(2), 45.0-49.9 kg/m(2), and >50.0 kg/m(2)). We analyzed data on five 30-day composite complication variables, including any complication, major complication, wound infection, systemic infection, and cardiac and/or pulmonary complication. RESULTS The odds ratio for 4 (any complication, major complication, wound infection, and systemic infection) of 5 composite complications started to increase exponentially once BMI reached 45.0 kg/m(2) or higher in TKA. Similarly, the odds ratio in 3 (any complication, systemic infection, and wound infection) of 5 composite complications showed similar trends in THA patients. These findings were further confirmed with propensity score matching and entropy balancing. CONCLUSIONS Our study suggested that there was a positive correlation between BMI and incidences of 30-day postoperative complications in both TKA and THA. The odds of complications increased dramatically once BMI reached 45.0 kg/m(2).

Avoiding costly hospitalisation at end of life: findings from a specialist palliative care pilot in residential care for older adults

Objectives Specialist palliative care is not a standardised component of service delivery in nursing home care in Australia. Specialist palliative care services can increase rates of advance care planning, decrease hospital admissions and improve symptom management in such facilities. New approaches are required to support nursing home residents in avoiding unnecessary hospitalisation and improving rates of dying in documented preferred place of death. This study examined whether the addition of a proactive model of specialist palliative care reduced resident transfer to the acute care setting, and achieved a reduction in hospital deaths. Methods A quasi-experimental design was adopted, with participants at 4 residential care facilities. The intervention involved a palliative care nurse practitioner leading ‘Palliative Care Needs Rounds’ to support clinical decision-making, education and training. Participants were matched with historical decedents using propensity scores based on age, sex, primary diagnosis, comorbidities and the Aged Care Funding Instrument rating. Outcome measures included participants’ hospitalisation in the past 3 months of life and the location of death. Results The data demonstrate that the intervention is associated with a substantial reduction in the length of hospital stays and a lower incidence of death in the acute care setting. While rates of hospitalisation were unchanged on average, length of admission was reduced by an average of 3.22 days (p<0.01 and 95% CI −5.05 to −1.41), a 67% decrease in admitted days. Conclusions The findings have significant implications for promoting quality outcomes through models of palliative care service delivery in residential facilities.

How free are free trading options

Abstract This study represents an empirical analysis of free trading options (FTOs), options that arise due to the arrival of adverse information. The analysis purports to measure three characteristics of these options: (i) the probability of the option ending in-the-money as a consequence of adverse information arrival, (ii) the value of the free trading option and (iii) the time taken for the free trading option to become in the money (its duration). The empirical methodology was applied to 163 earnings announcements on the Australian Stock Exchange (ASX) and a number of limit order strategies investigated. The results show that such free trading options do exist, and have value dependent particularly on trading volume, firm size and pre-announcement bid–ask spread.

Improving specialist palliative care in residential care for older people: a checklist to guide practice

Objectives Palliative care needs rounds are triage meetings that have been introduced in residential care for older adults to help identify and prioritise care for people most at risk for unplanned dying with inadequately controlled symptoms. This study sought to generate an evidence-based checklist in order to support specialist palliative care clinicians integrate care in residential nursing homes for older people. Methods A grounded theory ethnographic study, involving non-participant observation and qualitative interviews. The study was conducted at four residential facilities for older people in one city. Observations and recordings of 15 meetings were made, and complimented by 13 interviews with staff attending the needs rounds. Results The palliative care needs round checklist is presented, alongside rich description of how needs rounds are conducted. Extracts from interviews with needs rounds participants illustrate the choice of items within the checklist and their importance in supporting the evolution towards efficient and effective high-quality specialist palliative care input to the care of older people living in residential care. Conclusions The checklist can be used to support the integration of specialist palliative care into residential care to drive up quality care, provide staff with focused case-based education, maximise planning and reduce symptom burden for people at end of life.

Normalising and planning for death in residential care: findings from a qualitative focus group study of a specialist palliative care intervention

Background Improving access to palliative care for older adults living in residential care is recognised internationally as a pressing clinical need. The integration of specialist palliative care in residential care for older adults is not yet standard practice. Objective This study aimed to understand the experience and impact of integrating a specialist palliative care model on residents, relatives and staff. Methods Focus groups were held with staff (n=40) and relatives (n=17). Thematic analysis was applied to the data. Results Three major themes were identified. The intervention led to (1) normalising death and dying in these settings, (2) timely access to a palliative care specialist who was able to prescribe anticipatory medications aiding symptom management and unnecessary hospitalisations and (3) better decision-making and planned care for residents, which meant that staff and relatives were better informed about, and prepared for, the residents likely trajectory. Conclusions The intervention normalised death and dying and also underlined the important role that specialists play in providing staff education, timely access to medicines and advance care planning. The findings from our study, and the growing wealth of evidence integrating specialist palliative care in residential care for older adults, indicate a number of priorities for care providers, academics and policymakers. Further work on determining the role of primary and specialist palliative care services in residential care settings is needed to inform service delivery models.

General Equilibrium Analysis of Hold‐Up Problem and Non‐Exclusive Franchise Contract

In this paper, we develop a general equilibrium model that examines the emergence of non-exclusive franchise contracts in the presence of the franchisor hold‐up problem. Our model of an endogenous franchising network underscores the trade‐off between the cost associated with specifying and enforcing the contractual terms and the cost associated with broadening the relationships with multiple franchisors. We show that when the contracting cost relative to the relational cost is high and when the economies of specialization is low, a non‐exclusive franchise contract is an optimal contractual arrangement to mitigate franchisor opportunism.

A manikin-based evaluation of a teaching modality for ultrasound-guided infraclavicular longitudinal in-plane axillary vein cannulation in comparison with ultrasound-guided internal jugular vein cannulation: A pilot study

Background and Aims: Ultrasound (US)-guided infraclavicular approach for axillary vein (AXV) cannulation has gained popularity in the last decade. Material and Methods: In this manikin study, we evaluated the feasibility of a training model for teaching AXV cannulation. The learning pattern with this technique was assessed among attending anesthesiologists and residents in training. Results: A faster learning pattern was observed for AXV cannulation among the attending anesthesiologists and residents in training, irrespective of their prior experience with US. It was evident that a training modality for this technique could be easily established with a phantom model and that hands-on training motivates trainees to embrace US-based central venous cannulation. Conclusion: A teaching model for US-guided infraclavicular longitudinal in-plane AXV cannulation can be established using a phantom model. A focused educational program would result in an appreciable change in preference in embracing US-based cannulation techniques among residents.

The Impact of Broker Market Structure on Stock Liquidity

We investigate the extent to which the liquidity of listed stocks is affected by the market structure under which stockbrokers provide a combination of stock trading, research, and investment banking services. Six market structures of differing degrees of competitiveness are identified for brokers operating in the Australian equity market. We find that less competitive structures tend to associate with lower stock liquidity; and that shifts in broker market structure align with changes in liquidity over time. Further, broker market structures appear to interact with the provision of services by brokers, such that additional services improve liquidity to a greater extent under less competitive structures. Our research shows that the market structure for brokerage services acts as an additional determinant of the market liquidity of stocks.

The Shifting Ownership Structure of State-Owned Enterprises: Performance, Pyramids, and Political Regimes

We examine changes to corporate ownership in nine East Asian countries following the 1997 Asian Financial Crisis. Countries with lower incomes and in which policy making involves greater transactions costs (i.e., veto points) have more firms with state ownership. Partial state ownership appears to be effective insurance against crisis. Firms with minority state ownership exhibit 5% (annualized) lower idiosyncratic volatility in the quarter of the Lehman Brothers collapse than firms with either no or dominant state ownership. Minority state-owned firms also enjoy a higher abnormal return of 3.7% and 6.1% in the two quarters following the collapse of Lehman Brothers.

Migration of Trading and the Introduction of Single Stock Futures on the Underlying U.S. Stocks

This study investigates where liquidity and informed trading takes place following the introduction of single stock futures (SSF) contracts on the OneChicago futures exchange. Specifically, we analyze the size and composition of proportional spreads for two sets of stocks, those that have single stock futures contracts and a matched control sample that does not have such contracts. We find that, after controlling for changes in spread determinants, the average proportional spreads, on average, decrease significantly after SSF are introduced. For NYSE stocks, while the average daily trading volume in the cash market is reduced by 389,000 shares, we find a corresponding increase in the average percentage of the adverse selection component in the spread of the cash asset. This pattern indicates a migration of liquidity trading to the SSF market as fund managers appear to adjust their portfolio positions in the secondary SSF market rather than in the primary stock market.