A comparison of preferences for two GLP-1 products – liraglutide and exenatide – for the treatment of type 2 diabetes

Abstract

Objective:

To use time trade-off (TTO) to compare patient preferences for profiles of two glucagon-like peptide (GLP-1) products for the treatment of type 2 diabetes (liraglutide and exenatide) that vary on four key attributes – efficacy (as measured by hemoglobin A_1C), incidence of nausea, incidence of hypoglycemia, and dosing frequency (QD vs. BID) – and measure the contribution of those attributes to preferences.

Methods:

A total of 382 people with T2DM were recruited to participate in an internet-based survey consisting of a series of health-related questions, a conjoint exercise and a set of time trade-off items. In the conjoint exercise, respondents were presented with eight pairs of hypothetical GLP-1 profiles, and completed a time-tradeoff exercise for each pair.

Results:

The product profile representing liraglutide was preferred by 96% of respondents and resulted in significantly higher health utilities (0.038) than the product profile representing exenatide (0.978 vs. 0.94, p?<?0.05). Estimated preference scores from the conjoint analysis revealed that efficacy measured by hemoglobin A_1C is the most important attribute, followed by nausea, hypoglycemia, and dosing schedule.

Limitations:

On-line participants may not represent ‘typical’ type 2 diabetes patients, and brief product profiles represented results from clinical trials, not clinical practice

Conclusion:

Based on the four attributes presented, patients prefer liraglutide over exenatide. Preference is based on superior efficacy and less nausea more than less hypoglycemia and once-daily dosing.     

Cross-sectional tests of the CAPM and Fama–French three-factor model

Grouping does not produce a wide range of betas. Consequently, cross-sectional tests of the CAPM are bound to lack power. This paper provides a simple way to alleviate the problem by repackaging the data with zero-weight portfolios. When the CAPM is true and the data are repackaged, simulation shows that the average values of the intercept and slope converge to their true values more rapidly and there are striking increases in R² and the power of the tests. Empirical results are dramatically different in datasets with and without the zero-weight portfolios.     

Currency bid-ask spread dynamics and the Asian crisis: Evidence across currency regimes

Using a sample of 21 emerging and developed country currencies, we evaluate the impact of the Asian crisis on bid-ask spreads. While the crisis had widespread and uniform volatility effects, the spread effects were not uniform across emerging and developed country currencies. For Asian emerging markets, spreads widened and spread volatility increased significantly during the crisis, while developed markets spreads narrowed and spread volatility decreased significantly. We investigate the impact of more flexible and less flexible exchange rate regimes on bid-ask spreads using panel data. In general, countries with tightly-managed regimes have significantly lower spreads than countries with more freely-floating regimes, while controlling for the influence of other factors such as volatility. Asian developing market spreads are higher than spreads of the other countries, again, after controlling for the influence of other factors.