standard deviation (SD) – the standard deviation from a mean average, is a measure of the degree of variation from the mean.
Glossary
Selected words and phrases
protozoa – a single-celled animals that are larger and more complex than bacteria.
haemoglobin – substance in red blood cells that carries oxygen.
specificity – when referring to the accuracy of a test result, specificity refers to the proportion of people who do not have an illness or disease who have a negative test result.
If a test has low specificity, the concern is over false-positive results – where people who to not have a condition are wrongly diagnosed as having it.
If a test has high specificity, then people who to not have a condition are correctly ruled out from the condition.
For a serious condition, high specificity is essential to prevent people being unnecessarily treated.
See sensitivity.
X-ray – an abbreviation for x-radiation. An X-ray lung scan is a common way to look for evidence of TB infection. X-rays can also diagnose bone fractures.