In both high- and low-income countries there is considerably more undernutrition in the community than in hospital. However, the principles are very similar: detection of malnutrition and the underlying risk factors; treatment of underlying disease processes and disabilities; correction of specific nutrient deficiencies and provision of appropriate nutritional support. This typically begins with dietary advice, and may involve the provision of 'meals on wheels' by social services. A systematic review of the use of nutritional supplements in the community came to the following conclusions:
Supplements are generally of more value in patients with a BMI < 20 kg/m 2 and children with growth failure (weight for height < 85% of ideal) than in those with better anthropometric indices. They are likely to be of little or no value in patients with little weight loss and a BMI > 20 kg/m 2 . The supplemental energy intake in such subjects largely replaces oral food intake.
Supplements may be of value in weight-losing patients (e.g. > 10% weight loss compared to pre-illness) with a BMI >20 kg/m 2 , and in children with deteriorating growth performance without chronic protein-energy undernutrition.
The functional benefits varied according to the patient group. In patients with chronic obstructive airways disease the functional benefits were increased respiratory muscle strength, increase in handgrip strength, and an increase in walking distance/duration of exercise. In the elderly the benefits were reduced number of falls, or increase in activities of daily living, and reduced pressure sore surface area. In patients with HIV/AIDS there were changes in immunological function and improved cognition. Patients with liver disease experienced a lower incidence of severe infections and had a lower frequency of hospitalization.
Acceptability and compliance are likely to be better when a choice of supplements (of type, flavour, consistency) and schedule are decided in conjunction with the patient and/or carer. Changes in these may be necessary when there is a change in patterns of daily activities, disease status, and 'taste fatigue' with prolonged use of the same supplement.
Nutritional counselling and monitoring is recommended before and after the start of supplements
Some patients receive enteral tube feeding and parenteral nutrition at home. At any one point in time in developed countries enteral tube feeding occurs more frequently at home than in hospital. In adults the commonest reason for starting home tube feeding is for swallowing difficulties. This involves patients with neurological disorder, such as motor neurone disease, multiple sclerosis and Parkinson's disease, but the commonest single diagnosis is cerebrovascular disease. In 1998 it was estimated that almost 2% of patients who had a stroke in the UK received home enteral tube feeding (HETF).
Fifteen per cent of patients were able to resume full oral nutrition after a year. It is therefore necessary to intermittently assess the swallowing capabilities of patients in order to avoid unnecessary tube feeding. The patients and/or carers should have adequate training, contacts with appropriate health professions, and a reliable delivery service for feeds and ancillary equipment. They should also be clear about how to manage simple problems associated with the feeding tube, which is usually a gastrostomy tube rather than a nasogastric tube.