When Studies Collide*

Environmental epidemiology increasingly is being used as a foundation for environmental health policy. Since environmental epidemiologic studies have increased dramatically in number, approaches are needed to interpret them. Two approaches used in epidemiology are rules of evidence and meta-analysis. Rules of evidence pertain to the consistency, strength, uniqueness, and medical basis of the relationship between disease and risk factors such as chemicals. Meta-analysis is a systematic and rigorous approach to comparing studies and understanding their heterogeneity. Dioxins, benzene, and formaldehyde are three chemicals that are at the forefront of health policy debates. These chemicals illustrate some of the conditions under which researchers are drawn or are not drawn to approaches to compare studies. A meta-analysis was not conducted for dioxins or benzene, but was conducted for formaldehyde. Rather than addressing study comparisons, epidemiologic studies of dioxins are focusing on expanding the number of health effects studied and obtaining greater specificity for exposures, whereas studies of benzene are focusing on effects at low dose exposures. In the case of formaldehyde, meta-analysis has strengthened the evidence for some health effects beyond what individual studies could provide. Thus, whether rules of evidence and meta-analysis approaches to synthesizing information are used can depend upon where the debates are focused.     

Transformational versus transactional styles of cabinet leadership in Australian politics

Burns's classic study of leadership distinguished two types of leader. Transformational leaders are visionaries who are able to persuade followers to transcend their own self‐interest for the sake of a larger good. Transactional leaders, on the other hand, base their relationships with followers on an exchange, such as jobs for votes. The transformational/transactional model of leadership has been adapted by Bass for use in organisations. However, Burns's analysis focuses on what may be termed macro‐level leadership of entire states or organisations, whereas Bass's approach is used to study micro‐level leadership where there is ongoing direct interaction between leader and followers. This paper examines the cabinet leadership styles of four Australian political leaders: Malcolm Fraser, Bob Hawke, John Cain and Joh Bjelke‐Petersen. Cabinet ministers who served under these leaders were asked to complete a questionnaire rating the leadership behaviours they experienced. The results are compared with the evidence on leadership style presented in biographical accounts.