While insomnia disorder can be defined, there is no objective test for insomnia. It is normally evaluated clinically, such as by discussing symptoms and sleep quality, or by using a sleep diary to identify potentially significant influences on sleep behaviour.4

A number of screening tools with clinical rating scores have been developed to help assess the level of sleeping problems. The Pittsburg Sleep Quality Index (PSQI), published in 1989, has been used significantly in psychiatric research and practice. The Sleep Condition Indicator (SCI) was published in 2014 to evaluate insomnia disorder in everyday clinical practice.10,11

NHS Health A to Z (www.nhs.uk/conditions/insomnia/) offers users a sleep self-assessment based on the Sleepio Sleep Test using the 8-item SCI to give a ‘sleep score’. The questions cover how long it takes to get to sleep, periods of waking, frequency, and the impact.1,12