Real-world comparison of all-cause hospitalizations,hospitalizations due to stroke and major bleeding,and costs for non-valvular atrial fibrillation patients prescribed oral anticoagulants in a US health plan

Aims: To compare the risk of all-cause hospitalization and hospitalizations due to stroke/systemic embolism (SE) and major bleeding, as well as associated healthcare costs for non-valvular atrial fibrillation (NVAF) patients initiating apixaban, dabigatran, rivaroxaban, or warfarin.

Materials and methods: NVAF patients initiating apixaban, dabigatran, rivaroxaban, or warfarin were selected from the OptumInsight Research Database from January 1, 2013–September 30, 2015. Propensity score matching (PSM) was performed between apixaban and each oral anticoagulant. Cox models were used to estimate the risk of stroke/SE and major bleeding. Generalized linear and 2-part models were used to compare healthcare costs.

Results: Of the 47,634 eligible patients, 8,328 warfarin-apixaban pairs, 3,557 dabigatran-apixaban pairs, and 8,440 rivaroxaban-apixaban pairs were matched. Compared to apixaban, warfarin patients were associated with a significantly higher risk of all-cause (hazard ratio [HR]?=?1.30; 95% confidence interval [CI]?=?1.21–1.40) as well as stroke/SE-related (HR?=?1.60; 95% CI?=?1.23–2.07) and major bleeding-related (HR?=?1.95; 95% CI?=?1.60–2.39) hospitalization; rivaroxaban patients were associated with a higher risk of all-cause (HR?=?1.15; 95% CI?=?1.07–1.24) and major bleeding-related hospitalization (HR?=?1.71; 95% CI?=?1.39–2.10); and dabigatran patients were associated with a higher risk of major bleeding hospitalization (HR?=?1.46, 95% CI?=?1.02–2.10). Warfarin patients had significantly higher major bleeding-related and total all-cause healthcare costs compared to apixaban patients. Rivaroxaban patients had significantly higher major bleeding-related costs compared to apixaban patients. No significant results were found for the remaining comparisons.

Limitations: No causal relationships can be concluded, and unobserved confounders may exist in this retrospective database analysis.

Conclusions: This study demonstrated a significantly higher risk of hospitalization (all-cause, stroke/SE, and major bleeding) associated with warfarin, a significantly higher risk of major bleeding hospitalization associated with dabigatran or rivaroxaban, and a significantly higher risk of all-cause hospitalization associated with rivaroxaban compared to apixaban. Lower major bleeding-related costs were observed for apixaban patients compared to warfarin and rivaroxaban patients.     

Does the Confucius Institute Network Impact Cultural Distance? A Panel Data Analysis of Cross‐Border Flows in and out of China

This paper examines the impact of cultural distance in general and the Confucius Institute Network in particular on cross‐border flows of tourists, goods and investment in and out of China. We estimate a panel gravity model of inbound and outbound flows between 2004 and 2012. We find that the presence of Confucius Institute(s) in the source country increases inbound tourism and equity flows and outbound export and FDI flows for China, while other measures of cultural distance have less of an impact.     

Asymmetric effect of basis on dynamic futures hedging: Empirical evidence from commodity markets

The dynamic minimum variance hedge ratios (MVHRs) have been commonly estimated using the Bivariate GARCH model that overlooks the basis effect on the time-varying variance–covariance of spot and futures returns. This paper proposes an alternative specification of the BGARCH model in which the effect is incorporated for estimating MVHRs. Empirical investigation in commodity markets suggests that the basis effect is asymmetric, i.e., the positive basis has greater impact than the negative basis on the variance and covariance structure. Both in-sample and out-of-sample comparisons of the MVHR performance reveal that the model with the asymmetric effect provides greater risk reduction than the conventional models, illustrating importance of the asymmetric effect when modeling the joint dynamics of spot and futures returns and hence estimating hedging strategies.     

Using high, low, open, and closing prices to estimate the effects of cash settlement on futures prices

Due to dwindling commercial interest in the feeder cattle futures contract, the Chicago Mercantile Exchange (CME) decided to replace the contract's physical delivery provision with a cash settlement provision, arguing that cash settlement would help reduce price volatility and attracts more commercial interests. In this article, we apply stochastic volatility models to investigate the CME conjecture, using four different estimators based on opening, high, low, and closing prices, respectively. With each estimator, we find that the volatility of the feeder cattle futures price decreases after the implementation of cash settlement. We conclude that the change in the contract specification enhances price discovery and the contract's hedging performance.     

Competition,regulation and bribery: A further note

In this note we extend the analysis of Beck and Maher (1989) concerning the effects of discriminatory anti-bribery regulation. We argue that their approaches are challengeable due to an additional assumption that is most likely inconsistent with the benchmark model. Upon discarding the controversial assumption, we have an asymmetric bribery game. The corresponding Bayesian Nash equilibrium is nonetheless possessed with the properties described in Beck and Maher, despite the fact that their approaches may be incorrect.     

Contract settlement specification and price discovery: Empirical evidence in Australia individual share futures market

This study applies Geweke [J. Am. Stat. Assoc. 76 (1982) 304] measures of information flow and dependence between Australian individual share futures (ISF) contract and its underlying stock market to investigate whether the price discovery function of futures price has been enhanced after the switch of futures contracts from cash settlement to physical delivery. It is found that the spot market leads the futures market as the futures trading volume is rather small. Further tests suggest that the switch from cash settlement to physical delivery in the ISF contracts has reinforced the information flow from the spot market to the futures market.     

The effect of liquidity constraints on futures hedging

This article assumes that because of liquidity constraints, a hedge program will be terminated if the cumulative loss from a futures position exceeds a certain threshold. The constraint leads to a smaller futures position. If the hedger has a quadratic utility function, then the optimal futures position is constant regardless of the parameter values and increases as the spot position or the conventional hedge ratio increases. When the capital allocation is small, the hedger tends to ignore this restriction and chooses a larger position. Consequently, the optimal position may decrease as the capital allocation increases. For a moderate capital allocation, the optimal position increases with an increasing capital allocation. Similar properties are established for exponential utility functions. © 2003 Wiley Periodicals, Inc. Jrl Fut Mark 23:603–613, 2003     

Comparison of hospital length of stay and hospitalization costs among patients with non-valvular atrial fibrillation treated with apixaban or warfarin: An early view

Objective: To quantify and compare hospital length of stay (LOS) and costs between hospitalized non-valvular atrial fibrillation (NVAF) patients treated with either apixaban or warfarin via a large claims database.

Methods: Adult patients hospitalized with AF were selected from the Premier Perspective Claims Database (01JAN2013-31MARCH2014). Patients with evidence of valvular heart disease, valve replacement procedures, or pregnancy during the index hospitalization were excluded. Patients treated with apixaban or warfarin during hospitalization were identified. Propensity score matching (PSM) was performed to control for baseline imbalances between patients treated with apixaban or warfarin. Primary outcomes were hospital LOS (days), post-medication administration LOS, and index hospitalization costs, and were compared using paired t-tests in the matched sample.

Results: Before PSM, 2894 apixaban and 124,174 warfarin patients were identified. Patients treated with warfarin were older and sicker compared to those treated with apixaban. After applying PSM, a total of 2886 patients were included in each cohort, and baseline characteristics were balanced. The mean (standard deviation [SD] and median) hospital LOS was significantly (p?=?0.002) shorter for patients treated with apixaban for 5.1 days (5.7 and 3) compared to warfarin for 5.5 days (4.8 and 4). The trend appeared consistent in the hospital LOS from point of apixaban or warfarin administration to discharge (4.5 vs 4.7 days, p?=?0.051). Patients administered apixaban incurred significantly lower hospitalization costs compared to those administered warfarin ($11,262 vs $12,883; p?<?0.001).

Conclusions: Among NVAF patients, apixaban treatment was associated with significantly shorter hospital LOS and lower costs when compared to warfarin treatment.     

Firm Value,Corporate Cash Holdings and Financial Constraint: A Study from a Developing Market

This paper investigates the nonlinear relationship between firm value and corporate cash holdings in a sample of non‐financial Vietnamese firms from 2008 to 2013. We focus on both static and dynamic regressions to test for a nonlinear relationship. Our results reveal an ‘inverse U‐shape’ relationship between firm value and cash holdings, which is in line with trade‐off theory. Specially, we further test whether the optimal cash level changes under different financial conditions. In turn, this paper shows evidence of a nonlinear relationship between firm value and cash holdings under different financial circumstances and that each type of firm will adjust its optimal cash level based on business conditions.