There are a number of instruments commonly used to determine the presence and severity of sleepiness or assess specific symptoms. For defined sleep disorders there are several well-validated condition-specific instruments in use, whereas for other sleep disorders there is a lack of widely accepted condition-specific instruments. All existing instruments typically cover only selected aspects of the whole-patient experience associated with sleep disorders. It would, therefore, be valuable for clinical practice and research to have a practical tool that covers the spectrum of symptoms and limitations in the functioning of all patients with sleep disorders, taking into account also the environments in which they live. To tackle this challenge, the ICF Research Branch, the World Health Organisation (WHO) and the World Association of Sleep Medicine (WASM) initiated a project to develop internationally-accepted, evidence-based, reliable, and valid ICF Core Sets for sleep.

The preparatory phase of the project included the following studies:

• A systematic literature review was performed to identify the areas of functioning, disability and health reported through patient-oriented instruments in sleep medicine (from the researcher's perspective).
• A qualitative study (6 focus groups with 27 participants) was performed to explore the lived experiences of persons with sleep disorders with regard to functioning and contextual factors.
• An expert survey was performed to identify relevant aspects of functioning and related environmental factors from the perspective of health professionals worldwide experienced in treating persons with sleep disorders (pool of 123 experts from 54 countries).
• To explore the health professional's perspective on the relevant problems experienced by individuals with sleep disorders using the ICF as a reference, a multicentre cross-sectional study with a convenient sample of 99 participants was performed by University clinics of Berne and Zurich and the Clinic Barmelweid (all Switzerland).

The information collected from these preparatory studies was presented at the international consensus conference, a multi-stage, iterative, decision-making and consensus process that took place at the Swiss Paraplegic Research (Switzerland) from 28-30 May 2009. At this consensus conference, 26 experts from 22 countries worldwide with different professional backgrounds decided which ICF categories are to be included in the first version of the ICF Core Sets for sleep.

120 ICF categories were selected for inclusion in the Comprehensive ICF Core for Sleep Disorders. Out of the 120 Comprehensive ICF Core Set categories, 15 second-level ICF categories were selected for the Brief ICF Core for Sleep Disorders. The ICF Core Sets for Sleep Disorders should be seen as an addition to established tools for collecting information (e.g., validated patient questionnaires, polysomnography, Multiple Sleep Latency Tests). It can serve as a comprehensive framework to structure available health information and to guide comprehensive, multidisciplinary treatment and follow-up of persons with sleep disorders. Validation studies are being conducted.

For more information, feel free to contact the ICF Research Branch (felix.gradinger@paranet.ch).

• Comprehensive Core Set for Sleep Disorders (download PDF)
• Brief Core Set for Sleep Disorders (download PDF)