1.2 Prevalence of malnutrition
Summary
Malnutrition is not a new problem, and with an ageing population it continues to be a major public health concern. It is not confined to developing countries but is highly prevalent in the European healthcare system and in other developed regions.
Based on work done in the UK (showing > 3 million adults are at risk of malnutrition) and extrapolated to the rest of Europe, an estimated 20 million adults are at risk of malnutrition in the European Union (EU) and 33 million adults are at risk across Europe.
In the U.S., studies indicate that 20–50% of hospitalised adults are at risk of malnutrition experience, with the prevalence being higher among those with chronic diseases or acute conditions. Additionally, many individuals at risk of malnutrition reside in community settings, especially older adults who are living alone or recovering from hospital stays.
Malnutrition is prevalent across all healthcare settings particularly in patients in hospital and in institutions:
- Large-scale studies show that about 1 in 4 adult patients in hospital are at risk of malnutrition or are already malnourished.
- Recent data indicate malnutrition rates as high as 20–50% in hospitalised adults, particularly among those with complex conditions like COVID-19.
- More than 1 in 3 patients in care homes are malnourished or at risk of malnutrition.
- As many as 1 in 3 older people living independently are at risk of malnutrition.
Whereas many studies have addressed the prevalence of malnutrition in hospitals, the prevalence in the community setting has received less attention. Data from 2021 show that 51% of adults at risk of malnutrition in the UK lived in their own homes, and 60% were in care homes, highlighting the burden of malnutrition in community settings.
Outpatients also show varying malnutrition prevalence rates, depending on their condition and the specialty setting:
- General outpatients: 7–16%.
- Cancer patients: 20–70%, with higher rates in advanced stages.
- COPD patients: Up to 50%.
- Gastroenterology patients, particularly those with IBD and cancer, have higher malnutrition rates.
Malnutrition is prevalent across all age groups:
- In adults it is particularly a problem in older people. In the UK Nutrition Screening Week Survey in 2020, the risk was 41% greater in hospital patients aged 65 years and over than in those aged under 65 years (41% vs 35%, p < 0.001).
- Older adults are especially vulnerable, with malnutrition rates 1.2 to 2.3 times higher than in younger patients. In some hospital wards, rates can reach up to 90%.
- Almost 1 in 5 children admitted to Dutch hospitals have acute or chronic malnutrition.
Malnourished children face longer hospital stays and more complications.
Malnutrition is common across a variety of patient groups e.g. in patients with gastrointestinal, respiratory and neurological disease. It is particularly prevalent in people with cancer, where rates of malnutrition have been found to be twice as high when compared with patients without cancer.
- In mental health units, malnutrition risk ranges from 12.5% to 55.6%, depending on the diagnosis.
Conclusion
Many studies have been published in many different parts of the world using a variety of screening tools and techniques designed to estimate the prevalence of malnutrition and risk of malnutrition. The variability in methods, such as the use of tools like MUST, MNA, and GLIM criteria, partly explains the wide range of reported prevalence rates. However, it is clear that all studies point to the same conclusion that malnutrition and the risk of malnutrition is very common in patients across the age range and across healthcare settings, and that it is of particular concern in older people. There is an urgent need for standardised screening and improved nutrition care to address the significant healthcare and economic burden posed by malnutrition.
Recommendations
On the issue of prevalence of malnutrition the MNI makes the following recommendations:
| Action | Issues to consider |
|---|---|
| A commitment should be made to systematically measure the prevalence of malnutrition and risk of malnutrition, and the results should be widely disseminated | – Measuring prevalence of malnutrition and risk of malnutrition is a key way of driving awareness of this important issue and calling for action, and should be considered in countries where this has so far not been done. The UK Nutrition Screening Week is an excellent example for countries to refer to |
| A common approach should be taken to measuring and documenting malnutrition and risk of malnutrition | – A common approach would be of great value to enable comparison of prevalence rates across healthcare settings and countries |
Malnutrition is not a new problem
- A systematic analysis of a large number of studies reporting on malnutrition according to healthcare setting and clinical condition from as early as the 1970s revealed a prevalence of adult patients with a BMI of < 20 kg/m2 of up to 60% in hospital and community settings across countries.53
- The analysis also showed that over 10% and up to 40% of children were at risk of malnutrition if WFH < 90% and HFA < 95% were used as the criteria.53
- The prevalence of malnutrition among older adults varies significantly based on healthcare settings, age, gender, and screening methods. Estimates range from 3% in community settings to 30% in rehabilitation and subacute care. Pooled data show an 8.5% prevalence in the community and 28% in hospital settings. Rates are higher in women, those over 80, individuals with comorbidities, and rural populations. 98