Meta-analysis: protein and energy supplementation in older people

Protein and energy undernutrition is common in older people, and further deterioration may occur during illness.

To assess whether oral protein and energy supplementation improves clinical and nutritional outcomes for older people in the hospital, in an institution, or in the community.

Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, HealthStar, CINAHL, BIOSIS, and CAB abstracts. The authors included English- and non-English-language studies and hand-searched journals, contacted manufacturers, and sought information from trialists. The date of the most recent search of CENTRAL and MEDLINE is June 2005.

Randomized and quasi-randomized controlled trials of oral protein and energy supplementation compared with placebo or control treatment in older people.

Two reviewers independently assessed trials for inclusion, extracted data, and assessed trial quality. Differences were resolved by consensus.

Fifty-five trials were included (n = 9187 randomly assigned participants). For patients in short-term care hospitals who were given oral supplements, evidence suggested fewer complications (Peto odds ratio, 0.72 [95% CI, 0.53 to 0.97]) and reduced mortality (Peto odds ratio, 0.66 [CI, 0.49 to 0.90]) for those undernourished at baseline. Few studies reported evidence that suggested any change in mortality, morbidity, or function for those given supplements at home. Ten trials reported gastrointestinal disturbances, such as nausea, vomiting, and diarrhea, with oral supplements.

The quality of most studies, as reported, was poor, particularly for concealment of allocation and blinding of outcome assessors. Many studies were too small or the follow-up time was too short to detect a statistically significant change in clinical outcome. The clinical results are dominated by 1 very large recent trial in patients with stroke. Although this was a high-quality trial, few participants were undernourished at baseline.

Oral nutritional supplements can improve nutritional status and seem to reduce mortality and complications for undernourished elderly patients in the hospital. Current evidence does not support routine supplementation for older people at home or for well-nourished older patients in any setting.