The effect of post-discharge oral nutritional supplements on outcomes after gastrointestinal surgery: A systematic review and meta-analysis

Malnutrition is a risk-factor for adverse postoperative outcomes. This systematic review and meta-analysis evaluated the impact of post-discharge oral nutritional supplements (ONS) on outcomes in patients undergoing gastrointestinal surgery. The Medline and Embase databases were searched for randomised clinical trials in patients undergoing gastrointestinal surgery who had received ONS for at least two weeks after discharge from hospital. The primary endpoint was weight change. Secondary endpoints included quality of life, total lymphocyte count, total serum protein and serum albumin. Analysis was performed using RevMan5.4 software. Fourteen studies with 2480 participants (1249 ONS/1231 controls) were included. Pooling of results revealed that a reduction in postoperative weight loss in patients taking ONS, when compared with control: overall weighted mean difference (WMD) −1.69 kg, 95% CI −2.98 to −0.41, P = 0.01. Serum albumin concentration was increased in the ONS group: WMD = 1.06 g/L, 95% CI 0.04 to 2.07, P = 0.04. Haemoglobin was also increased: WMD = 2.91 g/L, 95% CI 0.58 to 5.25, P = 0.01. Total serum protein, total lymphocyte count, total cholesterol and quality of life did not differ between the groups. Patient compliance was relatively poor across the studies and there was variability in the composition of ONS, volume consumed and surgical procedures performed. There was a reduction in postoperative weight loss and an improvement in some biochemical parameters in patients receiving ONS after gastrointestinal surgery. Future RCTs with more consistent methodologies are needed to investigate the efficacy of ONS after discharge from hospital following gastrointestinal surgery.