i-Base

Glossary

Selected words and phrases

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.

viral load – the amount of virus in a sample of blood or other fluid. With HIV this is commonly the amount of HIV in a millilitre (mL) of blood. See viral load test.

matched – in clinical trials matched refers to each group having similar age, gender, ethnicity, HIV duration, health etc in a study.

fold-change – a term relating to drug resistance after a phenotype resistance test.

4-fold resistance (also called a 4-fold loss in sensitivity) means you need to use four times the dose to get the same reduction in viral load.

HHV-8 – Human Herpes Virus-8. The virus associated with Kaposi’s sarcoma (KS). Also called Kaposi’s sarcoma-associated herpesvirus (KSHV).