STUDY POPULATION
A total of 120 patients attended to at the Costa del Sol Hospital were included. Participants met the following inclusion criteria: adults (18 years or older) who had not previously consulted with a dietician and who had been in the HD program for at least three months. HD sessions were held three times per week for four hours. No participants dropped out of the study following the intervention.
Ethical approval
was granted by Costa del Sol Research Ethics Committee on May 30, 2020 with approval number 85-05-2019. The ethical principles set forth in the most recent version of the Declaration of Helsinki and the standards of good clinical practice were adhered to. All participants signed an informed consent form prior to their inclusion in the study.
STUDY DESIGN
In this descriptive study, the nutritional care model for HD patients began with a complete nutritional assessment of food intake and symptoms that could affect nutritional status and QOL, in accordance with the clinical guidelines of The National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative on nutritional support for HD patients [6]. The type and degree of malnutrition observed determined the NIP indicated, which ranged from nutritional counseling to specialized nutritional support.
As per our hospital’s protocol, the MIS questionnaire is administered every three months and the KDQOL-SF™ is administered twice a year. Both are performed at the beginning of HD sessions by nutritionists and trained nursing assistants who work in the Nephrology Unit. Blood samples are taken at the beginning of the HD session.
Malnutrition-Inflammation Score
The MIS was used to determine NR and a nutritional assessment was subsequently used to establish a nutritional diagnosis. Following its calculation, patients were categorized as well-nourished or malnourished. Malnourished patients were then classified as having mild, moderate, or severe protein-energy malnutrition or protein malnutrition.
Although several methods have been used to assess nutritional status in HD patients, there is no gold standard technique. The MIS, described by Kalantar et al. [7], uses components of the conventional Subjective Global Assessment (SGA) [8] and also includes comorbidity according to time on HD as well as biochemical parameters such as albumin, total iron-binding capacity, and transferrin. The MIS has four sections: nutritional history, physical examination, body mass index, and laboratory values. Total scores range from 0 to 30 points and scores >5 indicate the presence of NR. The MIS is widely used in CKD patients [9, 10], is supported by studies which have demonstrated its value as a predictor of mortality and morbidity in HD patients [11, 12, 13], and is a useful tool for detecting PEW in CKD patients [14].
Quality of life
QOL was measured using validated Spanish version of the KDQOL-SF™ version 1.2 [15]. It includes 43 specific items for patients with kidney disease organized into 11 specific dimensions of the disease. They include symptom/problem list, effects of kidney disease, burden of kidney disease, work status, cognitive function, quality of social interaction, sexual function, sleep, social support, dialysis staff encouragement, and patient satisfaction. All of these aforementioned items form part of the kidney disease summary component (KDSC). Furthermore, the KDQOL-SF™ also includes a section with the 36 generic items of the SF-36 questionnaire. It is organized into eight dimensions and two summary scores: the physical component summary (PCS) and the mental component summary (MCS) scores. Items include physical functioning, role-physical, pain, general health, emotional well-being, role-emotional, social function, and energy/fatigue.
Each question is numerically coded and then scored on a scale of 0 to 100; higher values reflect better QOL. It also includes an item about health measured on a scale of 0-10, where 0 indicates "worst possible health (as bad as or worse than being dead)" and 10 indicates "best possible health."
Statistical methods
Data are presented as means ± standard deviation. Categorical variables are shown as percentages. The Pearson correlation coefficient was used for independent quantitative variables, the Mann-Whitney U test for dichotomous qualitative variables, and the ANOVA test for qualitative variables with three or more categories.
In order to explore how each sociodemographic and clinical characteristic influences QOL, a multiple linear regression analysis was performed. KDSC, PCS, and MCS were the outcome variables and backward stepwise selection was used for independent variables with an entry criterion of p<0.05 and an exit criterion of p>0.1. β-coefficients were calculated with the respective 95% confidence intervals.
The level of statistical significance was established as p<0.05. All data were analyzed using the SPSS statistical software package for Windows, version 15.0 (SPSS Inc., Chicago, Ill., USA).