Relevance of culture in studies of leadership: ignored or dismissed?

Asia Pacific Journal of Management - Until recently, conclusions drawn about leadership have been made from a decidedly Western perspective, primarily based on theory developed in the U.S. using...     

Major bleeding risk and healthcare economic outcomes of non-valvular atrial fibrillation patients newly-initiated with oral anticoagulant therapy in the real-world setting

Aims: This study compared the risk for major bleeding (MB) and healthcare economic outcomes of patients with non-valvular atrial fibrillation (NVAF) after initiating treatment with apixaban vs rivaroxaban, dabigatran, or warfarin.

Methods: NVAF patients who initiated apixaban, rivaroxaban, dabigatran, or warfarin were identified from the IMS Pharmetrics Plus database (January 1, 2013–September 30, 2015). Propensity score matching (PSM) was used to balance differences in patient characteristics between study cohorts: patients treated with apixaban vs rivaroxaban, apixaban vs dabigatran, and apixaban vs warfarin. Risk of hospitalization and healthcare costs (all-cause and MB-related) were compared between matched cohorts during the follow-up.

Results: During the follow-up, risks for all-cause (hazard ratio [HR]?=?1.44, 95% confidence interval [CI]?=?1.2–1.7) and MB-related (HR?=?1.57, 95% CI?=?1.0–2.4) hospitalizations were significantly greater for patients treated with rivaroxaban vs apixaban. Adjusted total all-cause healthcare costs were significantly lower for patients treated with apixaban vs rivaroxaban ($3,950 vs $4,333 per patient per month [PPPM], p?=?.002) and MB-related medical costs were not statistically significantly different ($100 vs $233 PPPM, p?=?.096). Risk for all-cause hospitalization (HR?=?1.98, 95% CI?=?1.6–2.4) was significantly greater for patients treated with dabigatran vs apixaban, although total all-cause healthcare costs were not statistically different. Risks for all-cause (HR?=?2.22, 95% CI?=?1.9–2.5) and MB-related (HR?=?2.05, 95% CI?=?1.4–3.0) hospitalizations were significantly greater for patients treated with warfarin vs apixaban. Total all-cause healthcare costs ($3,919 vs $4,177 PPPM, p?=?.025) and MB-related medical costs ($96 vs $212 PPPM, p?=?.026) were significantly lower for patients treated with apixaban vs warfarin.

Limitations: This retrospective database analysis does not establish causation.

Conclusions: In the real-world setting, compared with rivaroxaban and warfarin, apixaban is associated with reduced risk of hospitalization and lower healthcare costs. Compared with dabigatran, apixaban is associated with lower risk of hospitalizations.     

Viewpoint: Estimating the causal effects of policies and programs

Estimation, inference and interpretation of the causal effects of programs and policies have all advanced dramatically over the past 25 years. We highlight three particularly important intellectual trends: an improved appreciation of the substantive importance of heterogeneous responses and of their methodological implications, a stronger focus on internal validity brought about by the “credibility revolution,” and the scientific value that follows from grounding estimation and interpretation in economic theory. We discuss a menu of commonly employed partial equilibrium approaches to the identification of causal effects, emphasizing that the researcher's central intellectual contribution always consists of making an explicit case for a specific causal interpretation given the relevant economic theory, the data, the institutional context and the economic question of interest. We also touch on the importance of general equilibrium effects and full cost–benefit analyses.     

Is Africa integrating? Evidence from product markets

This paper presents a price-based assessment of product market integration in Africa using disaggregated retail prices for 91 products and 12 African cities from 1991 to 2008. We find evidence of substantial deviations from the law of one price ? product price differences between the cities averaged 76% over the period – a result that is consistent with the presence of large barriers to trade in the continent. Mean price differences across cities fell by close to a quarter over the period, but the decline was concentrated in the early 1990s with little progress subsequently, despite the regional trade policies implemented by the countries. Gravity-style estimates reveal that reductions in external tariffs and global trends towards price convergence in the early 1990s are the key contributors to the trend in price integration amongst the African cities.     

Can the academic literature contribute to the debate over mandatory audit firm rotation?

Recently, the Public Company Accounting Oversight Board (PCAOB) issued a concept release soliciting public recommendations to improve auditor independence and audit quality (PCAOB, 2011). The focus of the release is on mandatory audit firm rotation (MAFR) with a request for commentaries addressing the advantages and disadvantages of MAFR. In this paper, we briefly summarize the recent literature on mandatory audit firm rotation and suggest how it can be useful to regulators as they consider the implementation of mandatory rotation. We find that the conclusions reached about the possible effectiveness of MAFR appear to depend on the type of data used (voluntary vs. mandatory auditor changes), suggesting that regulators should exercise care when drawing inferences from past audit firm rotation research.