Monte Carlo theoretical trials of methods for assessing statistical significance for differences between adjusted odds ratios

Odds are generally defined as the number of successes divided by the number of failures in a given number of trials. An odds ratio is the ratio of one odds divided by another. Odds ratios can be adjusted to reflect associations with the outcome independently of the influence of associations with other variables. These are adjusted odds ratios. There are several well known methods for comparing odds ratios and testing for statistically significant differences between them. Analogous methods for adjusted odds ratios are not well known or well documented. One method for comparing adjusted odds ratios is explained by Hosmer and Lemeshow (Applied logistic regression, 2000). This method is used for the odds ratios for two variables from the same data set. The purpose of this analysis was to apply this method to a different situation: comparing odds ratios for the same variable from two different data sets. Monte Carlo trials were used to assess the performance of the method and these indicated the method performed well.     

Operational performance of U.S. public rail transit and implications for public policy

In today's tough economic environment, governments at all levels face significant budget shortfalls and public rail transit systems must compete with other public services for government subsidies. It is critical that public rail transit systems be concerned with their operational performance and efficient use of resources. In this paper, we develop a methodology that measures a rail transit system's performance relative to that of other rail transit systems, compares its performance to an appropriate efficient benchmark system, and identifies the sources of its inefficiency. We analyze the relationship between public subsidies and operational performance of public rail systems and show an inverse relationship between subsidization and efficiency.     

When does economic model type become a decisive factor in health technology appraisals? Learning from the expanding treatment options for relapsing–remitting multiple sclerosis

Objectives: Specific economic model types often become de facto standard for health technology appraisal over time. Markov and discrete event simulation (DES) models were compared to investigate the impact of innovative modeling on the cost-effectiveness of disease-modifying therapies (DMTs) in relapsing–remitting multiple sclerosis (RRMS). Fingolimod was compared to dimethyl fumarate (DMF; in highly active [HA] RRMS), alemtuzumab (in HA RRMS) and natalizumab (in rapidly evolving severe RRMS). Comparator DMTs were chosen to reflect different dosing regimens.

Materials and methods: Markov and DES models used have been published previously. Inputs were aligned in all relevant respects, with differences in the modeling of event-triggered attributes, such as relapse-related retreatment, which is inherently difficult with a memoryless Markov approach. Outcomes were compared, with and without different attributes.

Results: All results used list prices. For fingolimod and DMF, incremental cost-effectiveness ratios (ICERs) were comparable (Markov: £4206/quality-adjusted life year [QALY] gained versus DES: £3910/QALY gained). Deviations were observed when long-term adverse events (AEs) were incorporated in the DES (Markov: £25,412 saved/QALY lost, versus DES: £34,209 saved/QALY lost, fingolimod versus natalizumab; higher ICERs indicate greater cost-effectiveness). For fingolimod versus alemtuzumab, when relapse-triggered retreatment was included in the DES, large cost differences were observed (difference between incremental cost is £35,410 and QALY is 0.10).

Limitations: UK payer perspective, therefore societal approach was not considered. Resource utilization and utilities for both models were not derived from the subpopulations; as the focus is on model type, input limitations that apply to both models are less relevant.

Conclusions: Whilst no model can fully represent a disease, a DES allows an opportunity to include features excluded in a Markov structure. A DES may be more suitable for modeling in RRMS for health technology assessment purposes given the complexity of some DMTs. This analysis highlights the capabilities of different model structures to model event-triggered attributes.     

Perceptions of facilitators of a keypad‐based group support system

Organizations are using Group Support Systems (GSSs) to improve the quality of group meetings. Keypad‐based GSSs are a widely used form of this technology, yet there has been little research on their use and effects. This paper reports the findings of a survey of facilitators of a particular keypad GSS. Facilitators indicate that keypad technology improves the quality of meetings for a variety of tasks in a range of group settings and cultures. The findings are in general agreement with field studies of workstation‐based systems.     

An Academic Publisher’s Response to Plagiarism

Plagiarism strikes at the heart of academe, eroding the fundamental value of academic research. Recent evidence suggests that acts of plagiarism and awareness of these acts are on the rise in academia. To address this issue, a vein of research has emerged in recent years exploring plagiarism as an area of academic inquiry. In this new academic subject, case studies and analysis have been one of the most influential methodologies employed. Case studies provide a venue where acts of plagiarism can be discussed and analyzed in a constructive manner, and that is the primary purpose of this article. Unlike previous studies, however, we focus on the role of the publisher, a key player in dealing with acts of plagiarism, but one who has received little attention in the academic literature. Specifically, we examine how an academic publisher addressed allegations of plagiarism and how the publisher’s decision-making affected the outcome. We analyze the case by applying the guidelines from different frameworks and ethical theory and develop recommendations from the lessons evidenced, the second main objective of our article. This analysis advances the dialog on academic plagiarism by exploring the role of the publisher from a deontological perspective of ethical absolutism.