Pilot–pivotal trials for average bioequivalence

Before carrying out a full scale bioequivalence trial, it is desirable to conduct a pilot trial to decide if a generic drug product shows promise of bioequivalence. The purpose of a pilot trial is to screen test formulations, and hence small sample sizes can be used. Based on the outcome of the pilot trial, one can decide whether or not a full scale pivotal trial should be carried out to assess bioequivalence. This article deals with the design of a pivotal trial, based on the evidence from the pilot trial. A two-stage adaptive procedure is developed in order to determine the sample size and the decision rule for the pivotal trial, for testing average bioequivalence using the two one-sided test (TOST). Numerical implementation of the procedure is discussed in detail, and the required tables are provided. Numerical results indicate that the required sample sizes could be smaller than that recommended by the FDA for a single trial, especially when the pilot study provides strong evidence in favor of bioequivalence.     

Using Private Social Care Services in Finland: Free or Forced Choices for Older People?

ABSTRACT

Use of private social care services among older people is increasing in Finland. This study aims to understand why older people choose private care in a comprehensive tax-subsidized social care system and examines whether people choose private service as a free choice or a forced choice as well as what factors contribute toward making these choices. Data for this study (N = 1,436) were gathered in 2010 from people aged 75 and above living independently at home in two Finnish cities: Tampere and Jyväskylä. Data were analyzed with several quantitative tests: chi-squared tests, multinomial regression analysis, and qualitative content analysis (for the open-ended responses from the survey questionnaire). Findings reveal that people chose private services mostly because of the effortlessness involved in its use and of the need for additional services that are unavailable through municipality; for example, cleaning. Majority of the respondents performed a free choice to use private services. People who lived in a city center with a higher level of income and who needed more services were more likely to be constrained toward using private support. Major concern, due to diminishing public service provision, is about service accessibility of economically disadvantaged groups; therefore, more research is required to understand the effects of the growing care market in Finland.     

Trust in Risky Messages: The Role of Prior Attitudes

Risk perception researchers have observed a "negativity bias" for hazard-related information. Messages indicating the presence of risk seem to be trusted more than messages indicating the absence of risk, and risk perceptions seem more affected by negative than positive information. Two experiments were conducted to examine alternative explanations of this finding within the area of food additives. Study 1 (N = 235) extended earlier work by (a) unconfounding message valence (positive or negative) from message extremity (definite or null finding) and (b) exploring the role of prior attitudes. Results suggested that negative/risky messages were indeed trusted more even when extremity was taken into account. However, prior attitudes significantly moderated the effect of message valence on trust. Positive messages were distrusted only by those with negative prior attitudes. Study 2 (N = 252), further explored the role of prior attitudes and extended the work by examining reactions to risky messages about a positively viewed additive--a vitamin. The results again found a moderating effect of prior attitudes on message valence. Participants had greater confidence in messages that were more congruent with their prior attitudes, irrespective of valence. Furthermore, positive messages had a greater impact on risk perception than negative messages. These findings suggest that greater trust in negative messages about hazards may be a product of a "confirmatory" rather than a "negativity" bias.     

Information Specificity and Hazard Risk Potential as Moderators of Trust Asymmetry

Trust in risk managers appears to be an important antecedent of public acceptance for many hazards. However, such trust may be fragile since research suggests that negative performance information has a greater impact than positive performance information (Slovic, 1993). Closer examination of these findings suggests two potential moderators of this valence-related asymmetry-information specificity and hazard risk potential. First, we predicted that the asymmetry would be less evident for low versus high specificity information (risk management policies vs. concrete events). Second, we predicted that it would also be less evident for a low- versus high-risk hazard (pharmaceutical vs. nuclear industry). Study 1 reanalyzed Slovic's original trust asymmetry data for the nuclear industry. In line with Prediction 1, trust asymmetry was less evident for policy than event-related information. Using a new set of items with more clearly defined levels of specificity, Study 2 replicated and extended these findings for the high-risk hazard (nuclear power). In line with Prediction 2, trust asymmetry was even less evident for the low-risk hazard (pharmaceuticals). Positive policies in this industry actually had a greater impact on trust than negative ones, in contrast to previous findings. Results support an information diagnosticity account of earlier findings and suggest that trust in risk managers may be more robust than previously believed.