Insomnia Impact Scale

As the name implies, the Insomnia Impact Scale (IIS) assesses the impact of poor sleep on wakeful functioning. The IIS was developed by Hoelscher, Ware, and Bond in the early 1990s. The scale is based on a self-report questionnaire that measures the level of agreement, one through five, to a series of 40 statements. These statements cover physical, cognitive, emotional, social, and occupational aspects of poor sleep. Based on the overall scores (ranging between 40 and 200) and scores within subject areas, IIS administrators were able to discriminate people with insomnia that presented at a sleep disorder center, those in college, and self-reported normal sleepers. Based on a review of PubMed, the IIS does not appear to be widely used in published research studies since the phrase “Insomnia Impact Scale” does not return any exact results. Upon further investigation, the IIS appears to have been used in less than ten studies since its initial publication and validation. One limitation of the IIS is that the scale does not have published norms which to compare. Researchers have used a score of 125 and above as indicative of significant disruption in daytime functioning.

Sleep Disorders

Dyssomnias

Parsomnias