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International Restless Legs Syndrome Study Group Severity Rating Scale (IRLS)
Availability
Please visit this website for more information about the instrument: International Restless Legs Syndrome Study Group Severity Rating Scale
Classification
Supplemental - Highly Recommended: Parkinson's Disease (PD) Recommendations for use: Indicated for studies evaluating the intensity of RLS symptomatology and its impact on quality of life.
Short Description of Instrument
The International Restless Legs Syndrome Study Group Severity Rating Scale (IRLS) is a 10-item generic instrument for the evaluation of Restless Leg Symptom (RLS) severity and change over time in patients diagnosed with RLS. Evaluates the effect of RLS symptomatology over the past week.
Comments/Special Instructions
Evaluates the impact of RLS in mood, daily affairs, frequency, intensity, severity, presence of tiredness of hypersomnia, sleep impairment, relief, discomfort, and need to move.
Scoring and Psychometric Properties
Scoring: Higher scores indicate a greater RLS severity. Score ranges from 0 (no symptoms) to 40 (extreme impairment). Self-administered.
 
Psychometric Properties: The IRLS was developed based on repeated expert evaluation of potential items. The scale was found to have high levels of internal consistency, inter-examiner reliability, test-retest reliability over a 2-4-week period, and convergent validity (in primary RLS). Scale meets performance criteria for a brief, patient completed instrument that can be used to assess RLS severity for purposes of clinical assessment, research, or therapeutic trials. The scale has been used in several studies in PD.
Rationale/Justification
Strengths: It has been used in PD population; it can be used to assess the change in RLS symptomatology while evaluating the effect of medications in clinical trials. Translated into several languages such as Japanese and Portuguese.
 
Weaknesses: Depends on patient impression of his/her symptoms. This is a subjective measure and response to placebo is high in the trials.
References
Key Reference:
Abetz L, Arbuckle R, Allen RP, Garcia-Borreguero D, Hening W, Walters AS, Mavraki E, Kirsch JM. The reliability, validity and responsiveness of the International Restless Legs Syndrome Study Group rating scale and subscales in a clinical-trial setting. Sleep Med. 2006 Jun;7(4):340-9.
 
Additional References:
Allen RP, Kushida CA, Atkinson MJ; RLS QoL Consortium. Factor analysis of the International Restless Legs Syndrome Study Group's scale for restless legs severity. Sleep Med. 2003 Mar;4(2):133-5.
 
Walters AS, LeBrocq C, Dhar A, Hening W, Rosen R, Allen RP, Trenkwalder C; International Restless Legs Syndrome Study Group. Validation of the International Restless Legs Syndrome Study Group rating scale for restless legs syndrome. Sleep Med. 2003 Mar;4(2):121-32.
 
Wunderlich GR, Evans KR, Sills T, Pollentier S, Reess J, Allen RP, Hening W, Walters AS; International Restless Legs Syndrome Study Group. An item response analysis of the international restless legs syndrome study group rating scale for restless legs syndrome. Sleep Med. 2005 Mar;6(2):131-9.
 
Document last updated August 2022