ISI or Insomnia Severity Index is an assessment tool designed to determine the severity of someone’s insomnia. It is widely used in both clinical and observational studies as a way to screen and assess insomnia.
How the ISI works
The subject is asked series of 7 questions . They are asked to rate the following criteria from 0 to 4.
- Their difficulty falling asleep
- Their difficulty staying asleep
- Their difficulty waking up.
- Their satisfaction/ dissatisfaction with their current (the past two weeks) sleep pattern
- The extent to which their current sleep problem is noticeable to others and impacting their quality of life
- Their level of worry/distress regarding their current sleep problem.
- The extent to which their current sleep problem interferes with their daily life (fatigue, mood, concentration, memory, etc..
Their answers are added up and their total (between 0 and 28) determines how severe their insomnia is.
The ISI, Insomnia Severity Index is a self-assessment tool, so the answers are subjective. Nonetheless, it has been proven to be reliable and effective. That’s why it is widely used as an assessment tool. The ISI can represent the first step in someone’s journey to finding help to resolve their insomnia, or a check-in to later check the efficacy of the measures they take.
For a more in depth look
Obviously for a more precise idea of severity of someone’s insomnia or their progress as they try to resolve it, their ISI needs to be completed with more information, like objective sleep data. Among other things, Dreem 2 measures sleep with a precision that is equivalent to that of a polysomnography, providing a clear, detailed view of the state of your sleep night after night.