Effectiveness of oral nutritional supplements to prevent hospital malnutrition. Overview of systematic reviews

Introduction. Although oral nutritional supplements (ONSs) are among most popular interventions to prevent a condition of hospital malnutrition, their real benefits need to be clarified. Aim. To evaluate in adults the effectiveness of ONSs to prevent hospital malnutrition. Methods. Papers retrieval by querying biomedical databases The Cochrane Library, Medline, Embase, CINAHL. Overview of systematic reviews evaluated for methodological quality according to R-AMSTAR checklist with narrative synthesis of results. Results. Twenty-five systematic reviews met the inclusion criteria. Methodological quality was better in more recent studies. Low-moderate quality evidence showed a trend for decreasing mortality, complications, length of stay; there was no clear reduction in readmissions. Inadequate data do not allow to assess the impact on quality of life. The intervention seems promising for subjects over 75 years, malnourished, with pathological conditions of geriatric interest, in hospital or long-term care services, but differences are not always significant. The definition of malnutrition, screening procedures and assessment tools adopted varies widely, as well as the characteristics of participants, intervention and duration of studies included in systematic reviews; this makes difficult to estimate the net benefit due to ONSs. Conclusions. The intervention should be included in a general approach to nutrition in clinical practice. At present the role of ONSs to prevent hospital malnutrition is still unclear.