 There is no doubt that medical research is shaped by various external values, in ways similar to the value ladeness that is well-recognized in other areas of science (see entry on  scientific objectivity).  Many of these values create a variety of ethical dilemmas relating to equity of access to health care and similar. Even in recent years once medical research has been made more inclusive, this trend has introduced a host of additional philosophical and ethical issues (Epstein 2007). For our purposes, we will focus on the implications of the systematic exclusion of certain types of individuals, groups, or diseases from research for future research as well as clinical medical practice in terms of the validity of evidence produced and decisions made based on that evidence. 