Study design

A prospective, observational, multicenter real-life study was conducted.

Study population

All patients 18 years of age and over prescribed HEN treatment with nasogastric tube or PEG by the corresponding Clinical Nutrition Unit of 21 hospitals, who maintained their treatment at home or in a residence from 1 July 2016 to 1 July 2020, with stabilized underlying disease, who had accepted and signed the informed consent (patient or caregivers) and who fulfilled a series of the following clinical indications were included:

Mechanical impairment of swallowing or transit with severe aphagia or dysphagia requiring a feeding tube and/or PEG.

Neuromotor disorders that prevent swallowing or transit requiring a feeding tube and/or PEG.

Patients with special energy and/or nutrient requirements requiring a feeding tube and/or PEG.

The exclusion criteria were as follows: pregnant women, expected survival under 180 days, unstable patients, and a failure to sign the informed consent for any reason. In older patients with a scarce social and family environment, the educational program has been reinforced, and the health area nurse has been informed for further follow-up. This study was approved by the CHUG Ethics and Research Committee. The STROBE-nut checklist [16] was filled (Additional file 1: Table S1).

Clinical, biochemical and nutritional variables

The variables were collected at face-to-face, telephone and/or home visits (baseline, 3 and 6 months). At the initial visit, the following variables were collected: age, gender, comorbidity, diagnosis that led to the indication for HEN (neurological disease, neoplastic disease, stroke) and presence of malnutrition, and a nutritional assessment was performed. To calculate energy and protein requirements, the FAO/WHO/UNU formula was used considering the adjusted weight of the patients.

Parameters concerning the initiation and adequacy of HEN support according to the needs and clinical course of the patients were collected: calculation of calorie-protein requirements, type of polymeric EN formula (hyperproteic/hypercaloric [HP/HC], normoproteic/normocaloric [NP/NC] and diabetic), volume of nutritional formula, administration regimen, access route, average duration of use of enteral support and HEN-related complications. All formulas used were complete polymeric formulas. A complete hyperproteic/hypercaloric polymeric formula was defined when its protein content was greater than 18% of the total caloric value (TCV) and the caloric density greater than 1.30 kcal/ml. The complete normoprotein/normocaloric formula was defined when the protein content was equal or less than 18% of the TCV and the caloric density was between 0.9 and 1.10 kcal/ml. A diabetic diet was considered as a special polymeric formula characterized by lipids with a high content of monounsaturated fatty acids (FA), carbohydrates with low glycemic indices and soluble fiber.

The type of calorie, protein and protein-calorie malnutrition was determined according to the criteria of the "SENPE-SEDOM Document on the coding of hospital malnutrition" [17].

The following anthropometric and laboratory variables were collected at baseline and at 6 months: height (m), usual weight (kg), current weight (kg), BMI (kg/m2), percentage weight loss (%), mid-upper arm circumference (MUAC) (cm), glucose (mg/dl), albumin (mg/dl), prealbumin (mg/dl), transferrin (mg/dl), total cholesterol (mg/dl), HDL cholesterol (mg/dl), LDL cholesterol (mg/dl), triglycerides (mg/dl) and lymphocytes (mg/dl). Patients who experienced one or more problems (nausea, vomiting, diarrhea, constipation, abdominal distension, and regurgitation) were considered to have tolerance issues. Improved nutritional status was also assessed in terms of a reduction in severity of energy or protein malnutrition (severe to moderate, moderate to mild or mild to well nourished) and with changes in anthropometric and biochemical variables between the initial visit and at 6 months.

Educational programme compliance variables

An educational program was prepared with an initial session on the main complications of the feeding tube, delivery of written information and subsequent regular telephone sessions. It was recorded whether the clinical report and educational material had been delivered, if it had been adequately explained to the patient how to manage and maintain the diet, and the access route details, as well as any interim or final suspensions.

Statistical analysis

The data obtained were entered into an Access database®, available by contacting the authors. Statistics of central tendency were used to describe the variables (mean, standard deviation) because tests of normality of the data indicated that the data are normally distributed (Kolmogorov–Smirnov and Shapiro–Wilk tests). Qualitative variables were described by frequency and proportion. To assess any significant differences during the treatment period (baseline visit and 6-month visit), a paired mean difference (t-test for related data) or a Chi-square test (or Fisher's exact test when the conditions for applying the chi-square were not met) and McNemar's test were used as appropriate. If three periods were evaluated (baseline, 3 months and 6 months), an ANOVA was performed for repeated measures. Finally, a logistic regression model was used to identify the risk factors related to tolerance and adverse effects of supplementation. The significance level used was 5% (p-value < 0.05). All data were analyzed using version 24 of the SPSS statistical software.