i-Base

Glossary

Selected words and phrases

secondary mutation – see minor mutation.

TST – abbreviation for testosterone

IQR (inter-quartile range) – when using (median) average, the IQR gives an indication of the spread or range of results. Each quartile (1st, 2nd, 3rd and 4th) represents 25% of the results. The IQR represents the middle 50% of the results. See also range.

DAA (direct acting antiviral) – new hepatitis C drugs that work directly against the hepatitis C virus (HCV).

Since 2014, the following DAAs and fixed dose combinations have been approved – and more are in development. Links are to the EMA website for information on each DAA.

Previously, HCV was treated with pegylated interferon (PEG-IFN) plus ribavirin (RBV).

Even though HCV guidelines now only recommend oral DAA treatment, the high price of these medicines means that in many countries they are only available to people who have advanced liver damage.

sensitivity – when referring to the accuracy of a test result, sensitivity refers to the proportion of people with an illness or disease who have a positive test result.

If a test has low sensitivity, then false-negative results are the concern – where people have a condition but it is missed.

If a test has high sensitivity, then people are accurately diagnosed – and only a few people are missed.

For a serious condition, high sensitivity is essential to be able to identify people early.

Online calculator.

See specificity.

sensitivity – when referring to the activity of a drug, sensitive means that a drug still works. As resistance develops a drug becomes less sensitive.

A complete loss of sensitivity implies that a drug is no longer working.

It also means that your partner may benefit from counselling.