<unk>  (or, more generally, the descending subtraction task; DST), where a patient counts down from one hundred by<unk> , is a clinical test used to test cognition; for example, to help assess mental status after possible head injury, in suspected cases of dementia or to show sleep inertia. This well-known test, in active documented use since at least 1944, was adopted as part of the mini-mental state examination. The test is also used in determining when a patient is becoming unconscious under anaesthetic, for example prior to major dental surgery. On its own, the inability to perform<unk> ' is not diagnostic of any particular disorder or impairment, but is generally used as a quick and easy test of concentration and memory in any number of situations where clinicians suspect that these cognitive functions might be affected. Each subtraction is considered as a unit and calculations are made on the basis of the 14 possible correct subtractions, that is 93-86-79-72-65-58-51-44-37-30-23-16-9-2. Similar tests include<unk>  threes where the counting downwards is done by threes, reciting the months of the year in reverse order, or spelling 'world' backwards. A study involving uninjured high school athletes concluded that the<unk>  test is not appropriate when testing for concussion because it lacks specificity; the pass rate is too low to give any meaningful result. The ability to recite the months in reverse order was thought to be a more effective measure because the pass rate was higher for that test in uninjured athletes. The numbers of the<unk>  test are a recurring motif in Sarah Kane's play 4.48 Psychosis.
Serial sevens
All-on-4
Golden hour 
Everywhere at the End of Time
Days post coitum
Pod mod
DailyMed
Born in Bradford