Clinical efficacy The extent to which an intervention is active when studied under controlled research conditions. Clinical effectiveness How well a specific test or treatment works when used in the real world (for example, when used by a doctor with a patient at home), rather than in a carefully controlled clinical trial. Trials that assess clinical effectiveness are sometimes called management trials. Clinical effectiveness is not the same as efficacy. Chronic Heart Failure Glossary NICE 2018. All rights reserved. Subject to Notice of rights. ISBN: 978-1-4731-3093-7 Term Definition Clinician A healthcare professional who provides patient care. For example, a doctor, nurse or physiotherapist. Cochrane Review The Cochrane Library consists of a regularly updated collection of evidence- based medicine databases including the Cochrane Database of Systematic Reviews (reviews of randomised controlled trials prepared by the Cochrane Collaboration). Cohort study A study with 2 or more groups of people cohorts with similar characteristics. One group receives a treatment, is exposed to a risk factor or has a particular symptom and the other group does not. The study follows their progress over time and records what happens. See also observational study. Comorbidity A disease or condition that someone has in addition to the health problem being studied or treated. Comparability Similarity of the groups in characteristics likely to affect the study results (such as health status or age). Concordance This is a recent term whose meaning has changed. It was initially applied to the consultation process in which doctor and patient agree therapeutic decisions that incorporate their respective views, but now includes patient support in medicine taking as well as prescribing communication. Concordance reflects social values but does not address medicine-taking and may not lead to improved adherence. Confidence interval (CI) There is always some uncertainty in research. 