Malnutrition and quality of life in older people: a systematic review and meta-analysis.

Although the effects of malnutrition on morbidity and mortality of older people is well established, there has been little work done to investigate the relationship between malnutrition and quality of life (QoL) in this population. In order to facilitate further research and to aggregate existing evidence into a clear overview, a systematic review was conducted. The objective was to identify the literature on the topic, review the findings systematically, and assess the association between nutritional status and QoL. MEDLINE, EMBASE, CINAHL and Web of Science were searched for relevant studies published up to April 2011. References within identified studies also searched. The primary author extracted all data using a purpose-built form, and evaluated the quality of the studies using a published checklist. A second reviewer checked a random sample of articles independently. Evidence in the current review comes from both cohort studies and intervention trials. Results from the former suggested that individuals with malnutrition are more likely to experience poor QoL (OR: 2.85; 95% CI: 2.20-3.70, p<0.001). Consistent with this, interventions designed to improve nutritional status can also lead to significant improvements in QoL, both physical (standard mean difference 0.23, CI: 0.08-0.38, p=0.002) and mental aspects (standard mean difference 0.24, CI: 0.11-0.36, p<0.001). However, the results should be interpreted with caution in view of the poor quality of the included studies and the heterogeneity of methods employed in the assessment of both nutritional status and QoL. Future studies should carefully characterise their participants and use standardised parameters for nutritional and QoL assessments in order to achieve better evaluation and comparability of study results.