Task: Question Answering
Input (English): Context: Reported prevalence of restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED), varies from country to country, and methodologic inconsistencies limit comparison of data. Impact of RLS on quality of life and health has been studied primarily in industrialized countries, particularly Europe and the United States. Many studies have relied exclusively on self-report of symptoms or have assessed only medical populations. Recently, interest has emerged on the impact of WED in rural, underserved populations globally. In a population-based survey conducted in rural Ecuador, we assessed the relationship of psychological distress to WED, evaluated with the Depression Anxiety Stress Scales-21. WED was diagnosed through a 2-phase method in which all residents were screened with the International Restless Legs Syndrome Study Group (IRLSSG) questionnaire and all suspected cases were subsequently confirmed through expert medical examination. WED severity was assessed with the IRLSSG rating scale. Of 665 persons (mean [SD] age, 59.5 [12.6] years; women, 386 [58%]), 76 had depression, 93 had anxiety, and 60 reported stress. Forty persons (6%) had WED, with 15 (38%) having severe disease. In a regression model adjusted for age and sex, the prevalence of depression, anxiety, and stress was about 3 times greater among persons with WED than the general population. Although cross-sectional data cannot establish causation, this study shows the large behavioral health burden associated with WED in an untreated, rural population. 
 Question: Willis-Ekbom disease is also known as?
Output (English): restless legs syndrome