Health economic analyses in medical nutrition: a systematic literature review

Background: Medical nutrition is a specific nutrition category either covering specific dietary needs and/or nutrient deficiency in patients or feeding patients unable to eat normally. Medical nutrition is regulated by a specific bill in Europe and in the US, with specific legislation and guidelines, and is provided to patients with special nutritional needs and indications for nutrition support. Therefore, medical nutrition products are delivered by medical prescription and supervised by health care professionals. Although these products have existed for more than 2 decades, health economic evidence of medical nutrition interventions is scarce. This research assesses the current published health economic evidence for medical nutrition by performing a systematic literature review related to health economic analysis of medical nutrition. Methods: A systematic literature search was done using standard literature databases, including PubMed, the Health Technology Assessment Database, and the National Health Service Economic Evaluation Database. Additionally, a free web-based search was conducted using the same search terms utilized in the systematic database search. The clinical background and basis of the analysis, health economic design, and results were extracted from the papers finally selected. The Drummond checklist was used to validate the quality of health economic modeling studies and the AMSTAR (A Measurement Tool to Assess Systematic Reviews) checklist was used for published systematic reviews. Results: Fifty-three papers were identified and obtained via PubMed, or directly via journal webpages for further assessment. Thirty-two papers were finally included in a thorough data extraction procedure, including those identified by a "gray literature search" utilizing the Google search engine and cross-reference searches. Results regarding content of the studies showed that malnutrition was the underlying clinical condition in most cases (32%). In addition, gastrointestinal disorders (eg, surgery, cancer) were often analyzed. In terms of settings, 56% of papers covered inpatients, whereas 14 papers (44%) captured outpatients, including patients in community centers. Interestingly, in comparison with the papers identified overall, very few health economic models were found. Most of the articles were modeling analyses and economic trials in different design settings. Overall, only eight health economic models were published and were validated applying the Drummond checklist. In summary, most of the models included were carried out to quite a high standard, although some areas were identified for further improvement. Of the two systematic health economic reviews identified, one achieved the highest quality score when applying the AMSTAR checklist. Conclusion: The reasons for finding only a few modeling studies but quite a large number of clinical trials with health economic endpoints, might be different. Until recently, health economics has not been required for reimbursement or coverage decisions concerning medical nutrition interventions. Further, there might be specifics of medical nutrition which might not allow easy modeling and consequently explain the limited uptake so far. The health economic data on medical nutrition generated and published is quite ample. However, it has been primarily based on database analysis and clinical studies. Only a few modeling analyses have been carried out, indicating a need for further research to understand the specifics of medical nutrition and their applicability for health economic modeling.