The RELISH Study: Compliance and Palatability of Oral Nutritional Supplements in Hospitalised Older Adults

22% of hospitalised older adults are estimated to be in a state of malnutrition. Malnutrition, also known as undernutrition, is a lack of nutritional intake leading to decreased fat free mass and diminished physiological functioning. Malnutrition impairs patient recovery, increasing hospital length of stay and escalating healthcare costs. Therefore, the identification and management of malnutrition is a vital patient-centred outcome to enhance older adult's health and quality of life and to enable cost-effective treatment and care.

A key method to support individualised nutritional care of hospital in-patients is the use of oral nutritional supplementation (ONS). ONS are energy and nutrient dense products designed to increase dietary intake when diet alone is insufficient to meet daily nutritional requirements. Overall, research suggests favourable impacts of ONS on nutritional status and healthcare costs, while the impact on functional outcomes and mortality are more controversial. A burgeoning evidence base attests to the importance of considering acceptability and compliance of ONS on adequate intake and thus effectiveness of ONS in practice.

Patient compliance to ONS considers the relationship between the amount of ONS prescribed and the amount of ONS ingested and is important to maximise clinical and cost-effectiveness. Palatability refers to the hedonic (i.e., pleasantness) evaluation of sensory factors, such as taste and smell, leading to alterations in food or fluid consumption. Supplemental preference may be affected by a multitude of factors such as taste, colour, smell, after taste and texture. Typically, hospital patients are offered liquid based ONS (sip feeds). However, previous research has pinpointed that 56% of older adults on geriatric wards did not like sip feeds. Hence, exploration of compliance to different ONS formats is an important research direction to maximise malnourished older adult's nutritional intake.

Malnourished hospitalised older adults should be offered an improved range and provision of ONS to suit patient preferences and maximise intake. For instance, an attractive alternative strategy is the use of energy and protein-dense meals (via fortification) or snacks (supplementation), including fortified bread, protein-enriched main meals and between meal snacks, such as biscuits, yoghurt and ice cream. Yet this is an understudied area, with limited data investigating compliance to alternative ONS products compared to ready-made drinks in hospital, such as powdered ONS and snacks, or their clinical effectiveness. Therefore, the current study aimed to investigate the compliance and palatability of novel fortified porridge compared to traditional sip-feeds in malnourished hospitalised older adults.

Research questions include:

• What are the compliance rates (% intake) of fortified porridge compared to standard liquid based ONS in malnourished hospitalised older adults?
• What are the palatability ratings (e.g., taste) of fortified porridge compared to standard liquid based ONS in malnourished hospitalised older adults?
• What is the acceptability of fortified porridge compared to standard liquid based ONS in malnourished hospitalised older adults, including facilitators and barriers to their use on medical wards?

A mixed methods randomised controlled crossover design will be conducted to determine compliance and palatability of fortified porridge in malnourished hospitalised older adults compared to a liquid-based control ONS. The acceptability of products will be assessed through qualitative interviews to explore patients and healthcare professionals' experiences and views of using the nutritional supplements. Participants will be prescribed ONS twice per day for 4 days, in addition to normal meals, in a crossover design. The products will be offered in-between breakfast and lunch, and after dinner to reduce the detrimental long period of calorie absence experienced overnight.

Inclusion criteria

• Older adults ≥65 years
• Patients on University Hospital Southampton (UHS) acute medical wards
• Medium-high risk of malnutrition (MUST score 1-4)
• Able to provide written consent

Exclusion criteria

• Patients that have used ONS in previous month
• Receiving enteral or parental nutrition
• Patients with a MUST score >4 (severely malnourished)
• Patients with a BMI ≤15
• Patients with chronic liver disease, renal failure, dysphagia
• Patients who have had major surgery within the preceding month
• Patients with a terminal illness
• Patients receiving end of life care
• Patients unable to eat by mouth (Nil By Mouth [NBM])
• Patients who require alternative ONS as advised by dietetic support