Glossary

A part, share, or number considered in comparative relation to a whole, expressed as a fraction (ratio) or percentage. For example, in epidemiology, the number of people who have a disease compared with the total number of people studied.

In a prospective cohort study, groups of people are identified before they show any signs of disease and are followed up over time. Alternatively, in retrospective cohort studies, data is used that has already been collected (possibly over a long period of time) for other purposes.

Cohort studies are one type of observational study, in which the researcher does not perform any intervention (such as administering a medicine).

Cohort studies are useful when it would be unethical to carry out a randomised controlled trial (RCT). For example, it would be unethical to deliberately expose people to cigarette smoke or asbestos.

A prospective meta-analysis uses only trials that have been identified and selected before their results are known. This avoids some of the problems of meta-analyses.

Usually, meta-analyses are performed when individual trials have finished. However, collecting studies after their completion can lead to statistical problems. For example, if a meta-analysis is carried out because of knowledge of a particular positive trial result, this can influence how other studies are chosen for the meta-analysis and cause bias in the analysis. This is why prospective meta-analyses are performed.

The word 'proteome' is derived from 'Proteins expressed by a genome'. It refers to the entire set of proteins expressed and modified by a specific cell, tissue, or organism at a certain time, under defined conditions. The proteome changes constantly in response to intra- and extracellular environmental signals health or disease

A proteomic marker is one type of biological marker, or biomarker. The term is often used interchangeably with ˜protein marker™ and is a protein, or set of proteins, used as a biomarker.

Proteomics is a branch of biotechnology that applies the techniques of molecular biology, biochemistry, and genetics to study proteins, how they are modified, their structure, function, and interactions with one another. The goal of proteomics is to obtain a more global and integrated view of biology by studying all the proteins of a cell or tissue rather than each protein individually. Study methods include looking at protein-protein interaction, protein modifications, protein function, and protein localisation.

The protocol of a clinical trial is a document that contains:

• The objectives (aims) of the trial
• The trial design, including:
  • How participants will be selected
  • How many participants are needed;

  • What measurements and endpoints will be used; and

  • How bias will be minimised

Psychotropic substances affect brain function and alter mood, behaviour, consciousness or perception.

Public Health Genetics Foundation (PHGF) http://www.phgfoundation.org/"

An examination of how a health intervention (e.g. treatment, procedure, policy, etc.) might have broader implications for the health of a population. For example, a new therapy to treat HIV/AIDS may reduce the rate of HIV transmission within a community.