_Homework_table7.3

_Homework_table7.3 - effects. Selective loss of data...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Table 7.3 Some Bias Types and Their Potential Effects on the Results of Clinical Trials Types of Bias Potential Consequences Selection bias May affect external validity, especially if the study has no internal controls. Procedure selection Healthier patients selected for a particular treatment may cause it to look good. Postentry exclusion Over optimistic view of the treatment, especially side
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: effects. Selective loss of data Variety of effects depending on the mechanism of data loss. Ascertainment bias Treatment effect is brought more into alignment with prior expectation Retroactive definitions Strong anticonservative bias is possible. Uncontrolled covariate Confounding of treatment effect with covariate effect....
View Full Document

This note was uploaded on 12/30/2010 for the course BST 252 taught by Professor Tsodikov during the Winter '06 term at UC Davis.

Ask a homework question - tutors are online