Restless legs syndrome (RLS) is a sensorimotor condition that primarily results in sleep disruption and subsequent daytime functional symptoms, particularly for those individuals with moderate-to-severe cases. In recent years there has been a shift from using the name ‘Restless Legs Syndrome’ to using ‘Willis–Ekbom Disorder’ (WED), in order to address matters of stigma and title inaccuracy.
The currently accepted clinical diagnostic criteria for RLS (WED) are: 1) an urge to move the legs, usually accompanied by an uncomfortable sensation(s); 2) the uncomfortable sensation(s) begins or worsens during periods of rest; 3) the unpleasant sensations are partially or totally relieved by walking/movement; and 4) the urge to move is greater in the evening or night than during the day.1Recently, a fifth criterion has been added: the disorder cannot be accounted for as symptoms primary to another medical or behavioural condition.2,3 This helps differentiate RLS (WED) from other disorders that mimic the symptoms of RLS (WED). Mimics, such as leg cramps, peripheral neuropathy, radiculopathy, arthritic pain and positional discomfort, may make the diagnosis of RLS (WED) difficult3 or may lead to misdiagnosis, causing a negative impact on patient quality of life (QoL).
The full pathology of RLS (WED) is not yet entirely understood, but various studies have linked RLS to several neurological factors, including decreased iron content in the substantia nigra, decreased dopamine neurotransmission in the striatum and increased glutamate levels in the thalamus.4–6 RLS symptom severity can fall across the entire clinical spectrum ranging from mild, moderate, severe, to very severe; it is usually determined by frequency and severity of symptoms, in addition to its impact on patient QoL.7
Understanding QoL has been a topic of growing interest over the past few decades and may influence treatment options and the psychological well-being for those living with a chronic condition. Although there have been many studies investigating the diagnostic criteria, epidemiology and costs involved with RLS (WED), less attention has been paid to the cost and toll put upon the RLS patients’ QoL. Modern QoL studies tend to be multidimensional and cover physical, social, emotional, cognitive and work- and role-related aspects of patients’ lives through the use of questionnaires or interviews.8 Recent federal policy changes have illustrated the need for measuring QoL to supplement public health’s traditional measures of morbidity and mortality. To this end, Healthy People 2000, 2010 and 2020 identified QoL improvement as a central public health goal.9,10 To meet the goal of QoL improvement, QoL deficits must first be understood. A study by Abetz et al. used the Short Form 36 (SF-36) Health Survey to assess the following eight domains: physical functioning, role limitations due to physical problems, bodily pain,general health perceptions, vitality, social functioning, role limitations due to emotional problems and mental health.11 The authors also used a modified version of the International Restless Legs Scale-Patient Version (IRLS-PV) to assess the severity of RLS (WED) symptoms, which they categorised as mild, moderate or severe and found significantly lower SF-36 scores for RLS (WED) patients compared with the general population in all eight areas measured. Analysis of the IRLS-PV found that increased RLS (WED) severity had a significant effect on all areas of functioning, with the exceptions of physical functioning and general health. Furthermore, RLS patients had significantly lower scores in all eight domains compared with patients with hypertension, and significantly lower scores in six of the eight domains compared with patients with other cardiovascular conditions (i.e. congestive heart failure, myocardial infarction, angina).11 Their data show that RLS (WED), although classified as a sleep disorder, does not affect sleep alone. This disorder has a significant influence on patients’ QoL that extends beyond sleep, affecting patients’ social lives and emotional and psychological health.
Effects on Quality of Life
Epidemiology and Quality of Life Variation
The epidemiology of RLS (WED) has been the subject of numerous studies published in the last decade, and it has been previously found that RLS (WED) prevalence may vary by region, gender, ethnicity and age.12–14 The largest of these studies, the RLS Epidemiology, Symptoms and Treatment (REST) General Population Study, surveyed 15,391 adults across the US, France, Germany, Italy, Spain and the UK to determine the prevalence of those with clinically significant RLS (WED) symptoms.15 The total population that met all diagnostic criteria for RLS (WED) at least once per week was found to be 5 %. Almost 3 % of participants in the study were sub-classified as ‘sufferers’ because they experienced moderately or severely distressing symptoms at least twice per week. Of those designated RLS (WED) patients, more than 75 % reported sleep-related symptoms, 59.4 % reported pain associated with their symptoms, 55.5 % reported disturbed daytime functioning and 26.2 % reported mood disturbance. Women were twice as likely as men to have RLS (WED), and 64 % of patients were 49 years of age or older.15 In addition, one population survey conducted in Korea found the prevalence of RLS to be 12.1 % – a rate higher than that of North American and European regions, indicating that RLS may be linked to region or ethnicity.16 While women generally report worse QoL compared with men for medical conditions, and RLS occurs more frequently in women than in men, previous studies in RLS have shown that there are no significant differences in RLS symptom severity in relation to gender and there are no significant RLS-QoL differences in relation to gender.17–19 Few studies have specifically been conducted evaluating prevalence of RLS among African American, Hispanic or Asian American individuals. One study found that RLS is twice as prevalent in non-African American males and four times as prevalent in non-African American females compared with African American males and females, respectively.20 No QoL data have been reported in terms of variation in QoL for RLS patients by race/ethnicity, and this gap in the literature represents a need for further investigation.