This observational, cross-sectional, and single-centered study was carried out at the Karachi Institute of Kidney Diseases (KIKD). The data collection period lasted from July to December 2019.Informed consent from the participants was obtained before carrying out a face-to-face interview. We included all the patients above 18 years of age who were on hemodialysis for more than three months in our study. Any participant who had Parkinson's disease, psychosis, arthritis, and muscle pain was excluded from the study. Besides that, patients with incomplete labs and those who refused to provide consent were also excluded.
The questionnaire has four components. The first part comprises the socio-demographic and biochemical parameters of patients; the second one comprised of International Restless Legs Syndrome Study Group (IRLSSG) diagnosis and severity scales; the third section included the World Health Organization Quality of Life (WHO-QOL)-BREF scale and, the fourth part included the Hospital Anxiety and Depression Scale (HADS) scale. The socio-demographic and biochemical parameters encompassed age, gender, BMI, cause of renal failure, duration of hemodialysis, number of dialysis per week, a shift of dialysis, Hemoglobin levels, pre-dialysis urea, post-dialysis urea, calcium, phosphorous, albumin, and parathyroid hormone levels.
We used IRLSSG 2003 diagnostic criteria to diagnose RLS in participants [10]. The following four essential criteria must be fulfilled to diagnose RLS:
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An urge to move the legs, usually but not always accompanied by or felt to be caused by uncomfortable and unpleasant sensations in the legs.
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The urge to move the legs and any accompanying unpleasant sensations begin or worsen during rest or inactivity such as lying down or sitting.
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The urge to move the legs and any accompanying unpleasant sensations are partially or relieved by movement, such as walking or stretching, at least as long as the activity continues.
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The urge to move the legs and any accompanying unpleasant sensations during rest or inactivity only occur or are worse in the evening or night than during the day.
Following the diagnosis of RLS, IRLSSG Severity Scale was used to assess the severity of RLS symptoms. Those with a score of 31–40 were categorized as very severe; a score of 21–30, as severe; 11–20, as moderate, and 0–10, as mild.
The World Health Organization Quality of Life (WHO-QOL)-BREF questionnaire was used to assess the quality of life in hemodialysis patients [11]. It is a self-reporting questionnaire comprising 26 questions, which gauges the quality of life across four facets; physical, social, psychological, and environmental. Sensitivity for overall quality of life and overall health was evaluated independently. Responses to questions are on a 1–5 Likert scale where one denotes 'disagree' or 'not at all' and 5 denotes 'completely agree' or extremely. The raw score obtained from the WHOQOL-BREF was transformed into a linear scale between 0 and 100 following the scoring guidelines [12,13]. A higher score indicated a better QOL.
The Hospital Anxiety and Depression Scale (HADS) was used to screen patients for anxiety and depression [14]. HADS is a fourteen-item scale with seven items in each subscale; anxiety, and depression. A score of 0–7 is regarded as normal, 8–10 as borderline, and 11–21 as an abnormal case for each subscale.
We used SPSS version 25.0 (IBM Corp, New York USA) for the data analysis. Categorical variables were reported as frequencies and percentages and continuous variables as means and standard deviations. An independent two-sample t-test was run to compare the means of continuous variables between the hemodialysis patients with and without RLS, and the Chi-squared test was used to observe the association between the categorical variables of the two study groups. Median scores on the WHOQOL-BREF domains of RLS positive and negative patients were obtained using the Mann-Whitney U test. Results were interpreted with 95% confidence intervals, and a p-value of less than 0.05 was considered significant.