Sir,
The prevalence of restless legs syndrome (RLS)1 is estimated to be 15–30% in patients with kidney disease, far exceeding the prevalence of 1.9–4.6% in the general population.2–4 RLS requires a subjective report by the patient, and clinical diagnostic criteria are well specified, i.e. an urge to move the legs, usually accompanied by unpleasant sensations primarily in the legs; the urge to move or uncomfortable sensations begin or worsen during rest, repose or inactivity; the urge to move or uncomfortable sensations can be relieved by movement; the urge to move or uncomfortable sensations are worse in the evening or early part of the night than during the day.1 RLS has been associated with profound sleep disturbance, distress, decreased quality of life, cardiovascular morbidity and, possibly, higher rates of mortality1–4 in patients with end stage renal disease (ESRD). Our goal was to determine whether physicians in the USA treating ESRD patients diagnose RLS.
We investigated RLS in the US Renal Data System (USRDS), the national registry of kidney patients in the USA. A unique ICD-9 code for RLS (333.94) became effective from 1 October 2006.5 We examined claims files for patients who started renal replacement therapy after that date. The RLS ICD-9 code was present for only 0.8% of the 341 548 patients who started therapy from 2007 to 2009. Among patients who started therapy during 2007–9 and survived through 2009 (n = 249 009), the RLS code was present for 0.9%.
RLS is vastly underdiagnosed among patients with kidney failure in the USRDS. Lack of recognition of this common condition adds to the duress of the ESRD patient, as well as contributing potentially to additional morbidity. Absence of awareness of the syndrome is especially noteworthy, given the treatability of this distressing and highly prevalent patient-reported outcome.
Funding
This work was supported by United States National Institutes of Health contract HHSN267200715004C, ADB No. N01-DK-7-5004.
Conflict of interest: D.L.B.: Consultant, Ferring, New England Research Institute. Other authors have none to declare.
References
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