Psychological factors implicated in decision making about health and health outcomes

Abstract

The primary goal of the thesis was to investigate how several psychological factors influence decision making about health and health outcomes, in order to make recommendations about how to promote health and facilitate informed decision making among diverse and vulnerable people. To fulfill this goal we have adopted an interdisciplinary approach using theory and knowledge from the areas of risk communication, judgment and decision making, social psychology, cognitive science, health psychology, human factors engeneering, epidemiology, and medicine. To examine the influence of the selected factors, we have conducted both experimental and field research. Chapters 1 to 5 present a total of six studies, in which numerical information about health outcomes was communicated to participants (patients and physicians). In these studies we have used experimental methodologies and investigated how participants used this numerical information, what factors influenced their comprehension, and how the various psychological factors, alone or in combination, influenced their decisions. Chapters 6 to 10 present results of field research. In these chapters we have aimed to validate and extend some of the results obtained in the experiments in naturalistic settings. In addition, we have investigated the influence of psychological factors on health behavior and outcomes directly and in an ecological setting. To estimate generalizability, a diverse set of health contexts was used. The work also strategically investigated health decisions and outcomes that are among the major priorities of the World Health Organization (see www.who.int), including cancer (Chapters 1 to 3), the Ebola virus (Chapter 4), sexually transmitted diseases (Chapters 5, 9, 10), and cardiovascular disease (Chapters 6 to 8). We investigated the influence of the following factors: information about health, often of numeric probabilistic nature (Chapters 1 to 5, 9, 10), the cognitive skills and representations required to understand such information (Chapters 2 to 6), the format in which this information is presented (Chapters 1 and 4), the emotional responses that may have implications for health and health behavior (Chapters 1, 2, 4, 5, 7), people‘s previous beliefs or attitudes towards health behaviors (Chapters 2 and 5), and social support (Chapter 8).