Autonomy Term originating from the Greek autos (self) and nomos (rule or law) and meaning self-determination or selfrule. In some theories of biomedical ethics, respect for autonomy is the most important consideration. Discussions of autonomy focus on the necessary and sufficient conditions needed for autonomy.
In bioethics, the principle of autonomy primarily refers to the obligation of healthcare professionals to respect the right of patients to make their own decisions concerning treatment. Constraints on autonomy could be in the form of coercion and undue influence. Other constraints arise within the individual, who is, for example, not capable of making decisions for her or himself.
Bias A research study is generally open to a number of potential errors. Bias denotes a systematic error. Sources of bias are, for example, the assignment of comparison groups or unequal interventions in a trial.
Blinding There are two kinds of blinding. In a single-blind design the assignment of agents or procedures being tested are not known to the patients; in a double-blind design these assignments are not known to either the examining health care professionals or to the patients.
Cohort study In this type of study a group or groups of individuals are defined on the basis of presence or absence of exposure to a suspected risk factor or on the basis of being treated or not. The group is then followed for a certain period of time. In an 'experimental study' the difference between the comparison groups is intentionally introduced by the investigators.
Crossover study Both groups in a study receive both treatments but in the reverse order.