Outcomes of tumor necrosis factor inhibitor cycling versus switching to a disease-modifying anti-rheumatic drug with a new mechanism of action among patients with rheumatoid arthritis

Objectives: To examine treatment patterns, treatment effectiveness, and treatment costs for 1 year after patients with rheumatoid arthritis switched from a tumor necrosis factor inhibitor (TNFi) (adalimumab, certolizumab pegol, etanercept, golimumab, or infliximab), either cycling to another TNFi (“TNFi cyclers”) or switching to a new mechanism of action (abatacept, tocilizumab, or tofacitinib) (“new MOA switchers”).

Methods: This retrospective cohort study used administrative claims data for a national insurer. Treatment persistence (without switching again, restarting, or discontinuing), treatment effectiveness (defined below), and costs were assessed for the 12-month post-switch period. Patients were “effectively treated” if they satisfied all six criteria for a treatment effectiveness algorithm (high adherence, no dose increase, no new conventional synthetic disease-modifying anti-rheumatic drug, no subsequent switch in therapy, no new/increased oral glucocorticoids, and <2 glucocorticoid injections). Multivariable logistic models were used to adjust for baseline factors.

Results: The database included 581 new MOA switchers and 935 TNFi cyclers. New MOA switchers were 39% more likely than TNFi cyclers to persist after the switch (odds ratio [OR]?=?1.39; 95% confidence interval [CI]?=?1.12–1.74; p?=?.003) and 36% less likely to switch therapy again (OR?=?0.64; 95% CI?=?0.51–0.81; p?p?=?.006). New MOA switchers had 16% lower drug costs than TNFi cyclers (cost ratio?=?0.84; 95% CI?=?0.79–0.88; p?p?Limitations: Claims payments may not reflect rebates or other cost offsets. Medical and pharmacy claims do not include clinical end-points or reasons that lead to new MOA switching vs TNFi cycling.

Conclusions: These results support switching to a new MOA after a patient fails treatment with a TNFi, which is consistent with recent guidelines for the pharmacologic management of established rheumatoid arthritis.     

Factors Influencing Young Consumers’ Acceptance of Genetically Modified Food in India

We analyzed the determinants of acceptance of genetically modified food (GMF) by using the probit model. In this study, we found that around 41% of the students are willing to buy GMF, and acceptance of GMF is less in female respondents than male respondents. The findings indicate that in India, benefit perception of GMF outweighed the risk perception. We also found that respondents’ trust in international organizations for truthful information has a positive and significant influence on acceptance of GMF.     

The regulation of water services in the EU

The European Commission’s proposal for a Directive on the award of concession contracts has sparked vigorous public debate and intense opposition. This Directive is controversial because of the nature of the policy it proposes and because the sectors involved are highly sensitive. This Forum examines the weaknesses of the Commission’s proposal and presents an overview of the current issues in water regulation and the provision of water services. The authors analyse the regulation of natural monopolies, water efficiency and upstream competition in the water industry.     

Der EU Richtlinienvorschlag für erneuerbare Energien — Eine Analyse der Transferrestriktionen von Herkunftsnachweisen

Until now the promotion of renewable energies in Europe has been effected on the basis of different promotion systems of the Member States. Currently the EU-wide harmonisation of the promotion systems, from which yields of efficiency and a higher effectiveness are expected, cannot be enforced due to a discordance concerning the “right” promotion instrument.With the proposal for a directive on the promotion of renewable energies, published at the 23. January in 2008, the European Commission attempts to make a first move towards harmonisation. Besides existing promotion systems it will be possible to transfer Guarantees of Origin for renewable energies between Member States. Since, however, some Member States expect negative effects as a consequence of opening their markets the proposal comprises opportunities to restrict the transfer. The present scope of interpretation within the proposal allows for different options concerning the design of the transfer restrictions. These will be identified, analysed, and subsequently evaluated in this article. Despite of both extreme options, the possibility to entirely opt out of the transfer system and the obligation to completely participate in the transfer system, two further hybrid options are discussed. The latter are characterised by the possibility of Member States to restrict the transfer of Guarantees of Origin to a certain extent through a “system of prior authorisation”.     

Expectation formation and regime switches

Economic agents often have to make decisions in environments affected by regime switches but expectation formation has hardly been explored in this context. We report about a laboratory experiment whose participants judgmentally forecast three time series subject to regime switches. The participants make forecasts without context knowledge and without support from statistical software. Their forecasts are only based on the previous realizations of the time series. Our interest is the explanation of the average forecasts with a simple model, the bounds & likelihood heuristic. In previous studies it was shown that this model can explain average forecasting behavior very well given stable and stationary time series. We find that the forecasts after a structural break are characterized by a higher variance and less accuracy over several periods. Considering this transition phase in the model, the heuristic performs even slightly better than the Rational Expectations Hypothesis.     

The Causal Relationship Between Real Estate and Stock Markets

This paper examines the dynamic relationship that exists between the US real estate and S&P 500 stock markets between the years of 1972 to 1998. This is achieved by conducting both linear and nonlinear causality tests. The results from these tests provide a number of interesting observations which primarily show linear relationships to be spuriously affected by structural shifts which are inherent within the data. Linear test results generally show a uni-directional relationship to exist from the real estate market to the stock market. However, these results are not consistent with financial theory and for all sub-samples of the data. In contrast, the nonlinear causality test shows a strong unidirectional relationship running from the stock market to the real estate market, and is consistent in the presence of any structural breaks.     

Portfolio optimization based on GARCH-EVT-Copula forecasting models

This study uses GARCH-EVT-copula and ARMA-GARCH-EVT-copula models to perform out-of-sample forecasts and simulate one-day-ahead returns for ten stock indexes. We construct optimal portfolios based on the global minimum variance (GMV), minimum conditional value-at-risk (Min-CVaR) and certainty equivalence tangency (CET) criteria, and model the dependence structure between stock market returns by employing elliptical (Student-$t$ and Gaussian) and Archimedean (Clayton, Frank and Gumbel) copulas. We analyze the performances of 288 risk modeling portfolio strategies using out-of-sample back-testing. Our main finding is that the CET portfolio, based on ARMA-GARCH-EVT-copula forecasts, outperforms the benchmark portfolio based on historical returns. The regression analyses show that GARCH-EVT forecasting models, which use Gaussian or Student-$t$ copulas, are best at reducing the portfolio risk.     

Optimal Portfolios with Bounded Capital at Risk

We consider some continuous-time Markowitz type portfolio problems that consist of maximizing expected terminal wealth under the constraint of an upper bound for the capital at risk. In a Black–Scholes setting we obtain closed-form explicit solutions and compare their form and implications to those of the classical continuous-time mean-variance problem. We also consider more general price processes that allow for larger fluctuations in the returns.