The parameter in an equation derived from a regression analysis corresponding to the expected value of the response variable when all the explanatory variables are zero.

A term applied when two (or more) explanatory variables do not act independently on a response variable.

A procedure in which all patients randomly allocated to a treatment in a clinical trial are analyzed together as representing that treatment, whether or not they completed, or even received it. Here the initial random allocation not only decides the allocated treatment, it decides there and then how the patient’s data will be analyzed, whether […]

Surveys in which the primary sampling units are institutions, for example, hospitals. Within each sampled institution, a sample of patient records is selected.

A term used in the context of Bayesian inference to indicate a prior distribution that reflects empirical or theoretical information regarding the value of an unknown parameter.

Censored observations that occur for reasons related to treatment, for example, when treatment is withdrawn as a result of a deterioration in the physical condition of a patient. This form of censoring makes most of the techniques for the analysis of survival times, for example, strictly invalid.

A branch of applied probability theory applicable to many communication and signal processing problems in engineering and biology.

An observation that has a disproportionate influence on one or more aspects of the estimate of a parameter, in particular, regression coefficients. This influence may be due to differences from other subjects on the explanatory variables, an extreme value for the response variable, or a combination of these.

A range of statistics designed to assess the effect or influence of an observation in determining the results of a regression analysis. The general approach adopted is to examine the changes that occur in the regression coefficients when the observation is omitted.

The process of drawing conclusions about a population on the basis of measurements or observations made on a sample of units from the population.