Adherence to ketogenic dietary therapies in epilepsy: A systematic review of literature.

Treatment adherence, defined as the degree to which the patient actively follows the plan of care, is very difficult for subjects undergoing ketogenic dietary therapies (KDTs). This is a relevant issue because adherence to dietary therapies is considered 1 of the primary determinants of the treatment's success. This paper aimed to review the literature evidence about KDT adherence according to age and diagnosis of patients. Performed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses method, this systematic review included clinical trials and observational studies. The risk of bias was assessed by the RoB 2.0 Cochrane tool and the quality of evidence according to the Mixed Methods Appraisal Tool system. Twenty-two articles were included, with more than half (n = 12) having average quality (2-3 stars). The studies' heterogeneity in measuring adherence and diagnosis made it difficult to compare results. Mean adherence rates were 71.5%, 66%, and 63.9% for children, adolescents, and adults, respectively. Adherence and compliance rates varied according to the follow-up period (79.7%, 66.7%, and 37.7% at 6, 24, and 36 months, respectively). The most frequent reasons for low adherence were linked to inefficacy in seizure control, adverse effects, food refusal, difficulty in preparing KDT meals or diet restrictiveness, lack of motivation, poor parental compliance, or cost of the diet. To conclude, there is a lack of standardized tools to measure adherence. Several studies highlighted the families' challenges in adhering to KDTs. These factors should be considered when creating strategies and resources on family education.

Factor Analysis of the Brazilian Questionnaire on Adherence to Ketogenic Dietary Therapy: Keto-Check.

BACKGROUND: several strategies are used to assess adherence to ketogenic dietary therapies (KDTs), the most commonly used being ketonemia or ketonuria, despite their limitations. The purpose of this article is to carry out an exploratory and confirmatory factor analysis on the proposed Keto-check (adherence's KDT Brazilian questionnaire). METHODS: there was a methodological study of a quantitative nature, complementary to the analysis realized previously, with a complimentary sample. The factorial analysis was performed with Factor software for parallel exploratory analysis, replicability, and confirmatory factor analysis. Graphical representation was created according to the number of factors resulting from the analysis. RESULTS: 116 questionnaires were reached by complementary data collection (n = 69 actual data, complementing n = 47 previous data) through online forms. A polychoric correlation matrix suitability analysis resulted in a significant Bartlett statistic (p = 0.0001) and a Kaiser-Meyer-Olkin (KMO) test of 0.56. The parallel factorial analysis resulted in two factors, graphically represented as "efficacy" and "adherence". A confirmatory factor analysis, considered fair, indicated an RMSEA of 0.063, NNFI resulted in 0.872, CFI in 0.926, and GFI in 0.897. CONCLUSION: this study confirms the validity of Keto-check through a more detailed analysis. Adherence is the key to improving the effectiveness of KDTs; therefore, improving knowledge about it can lead to a better healthcare approach.

Validation of an Italian Questionnaire of Adherence to the Ketogenic Dietary Therapies: iKetoCheck.

Ketogenic dietary therapies (KDTs) are an effective and safe non-pharmacological treatment for drug-resistant epilepsy, but adherence can be challenging for both patients and caregivers. In Europe, there are no adequate tools to measure it other than monitoring ketosis. This study aimed to adapt and validate the Brazilian adherence questionnaire, Keto-check, into the Italian version: iKetoCheck. Using the Delphi technique, 12 judges validated the contents through agreement rates and the Content Validity Index (CVI). The iKetocheck was self-completed electronically by 61 drug-resistant epilepsy or GLUT1 deficiency patients within an interval of 15 days to measure its reproducibility. The test-retest reliability was evaluated using Pearson's correlation and relative significance test. Exploratory and confirmatory factorial analyses were made using Factor software version 12.03.02. The final tool, iKetoCheck, consists of 10 questions with 5-point Likert scale answers. It evaluates various aspects such as informing caregivers about the diet, organization of meals, measurement of ketosis, weighing food consumed, diet negligence, use of carbohydrate-free medications, attending follow-up visits, reading food labels, consulting an expert for dietary concerns, and cooking at home. The factorial analysis resulted in three factors: "attention," "organization," and "precision," with satisfactory results for indices in exploratory and confirmatory analyses. Although higher mean values of ketonemia measurement were observed in patients with a higher adherence score, these values were not statistically significant (p = 0.284). In conclusion, despite the small sample size, iKetoCheck is a valid tool for evaluating KDTs' adherence in Italian drug-resistant epilepsy or GLUT1 deficiency patients. It can provide valuable information to improve patient management and optimize the effectiveness of KDTs.