In a clinical trial, the investigators must specify<unk>  for participation in the study.<unk>  define the characteristics that prospective subjects must have if they are to be included in a study. Although there is some unclarity concerning the distinction between the two, the ICH E3 guideline on reporting clinical studies suggests that *<unk><unk>  concern properties of the target population, defining the population to which the study's results should be generalizable.<unk><unk>  may include factors such as type and stage of disease, the subject’s previous treatment history, age, sex, race, ethnicity. *<unk><unk>  concern properties of the study sample, defining reasons for which patients from the target population are to be excluded from the current study sample. Typical<unk><unk>  are defined for either ethical reasons (e.g., children, pregnant women, patients with psychological illnesses, patients who are not able or willing to sign informed consent), to overcome practical issues related to the study itself (e.g., not being able to read, when questionnaires are used for assessment of outcomes), or to eliminate factors that may limit the interpretability of study results (e.g., comorbidities).<unk><unk>  may lead to biases in the study's results.
Inclusion and exclusion criteria
Adverse outcome pathway
Clinical trial naming conventions
Sentinel event
Clinical endpoint
Clinical study report
Patient-reported outcome
Human subject research