Exclusion criteria (literature review) Explicit standards used to decide which studies should be excluded from consideration as potential sources of evidence. Exclusion criteria (clinical study) Criteria that define who is not eligible to participate in a clinical study. Extended dominance If Option A is both more clinically effective than Option B and has a lower cost per unit of effect, when both are compared with a do-nothing alternative then Option A is said to have extended dominance over Option B. Option A is therefore cost effective and should be preferred, other things remaining equal. Extrapolation An assumption that the results of studies of a specific population will also hold true for another population with similar characteristics. Follow-up Observation over a period of time of an individual, group or initially defined population whose appropriate characteristics have been assessed in order to observe changes in health status or health-related variables. Generalisability The extent to which the results of a study hold true for groups that did not participate in the research. See also external validity. Gold standard A method, procedure or measurement that is widely accepted as being the best available to test for or treat a disease. GRADE, GRADE profile A system developed by the GRADE Working Group to address the shortcomings of present grading systems in healthcare. The GRADE system uses a common, sensible and transparent approach to grading the quality of evidence. The results of applying the GRADE system to clinical trial data are displayed in a table known as a GRADE profile. Harms Adverse effects of an intervention. Chronic Heart Failure Glossary NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 Term Definition Health economics Study or analysis of the cost of using and distributing healthcare resources. 