Beneficial effects of preoperative oral nutrition supplements on postoperative outcomes in geriatric hip fracture patients A PRISMA-compliant systematic review and meta-analysis of randomized controlled studies

Background: Geriatric hip fracture patients often present malnutrition during admission, which leads to higher morbidity and mortality. Protein-based oral nutrition supplements may improve nutritional status. We conducted this systematic review and meta-analysis of randomized controlled trials (RCTs) according to the PRISMA guidelines to elucidate whether preoperative nutrition supplements can improve postoperative outcomes in geriatric hip fracture patients. Methods: Only RCTs conducted to compare postoperative outcomes between geriatric hip fracture patients (>60 years old) receiving preoperative oral protein-based nutrition supplement (ONS group) and those who receiving regular diet (Control group) were included. PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception until August, 2021. Postoperative outcomes, including complications, length of hospital stay, and in-hospital mortality, were assessed. Results: A total of 5 RCTs with 654 geriatric hip fracture patients (ONS group: 320 subjects; Control group 334 subjects) were included. Our data revealed that postoperative complications risk in the ONS group was significantly lower than in the Control group (odd’s ratio: 0.48, 95% confidence intervals [CI]: 0.26–0.89, P = .02, I² = 64%). However, no significant differences in the length of hospital stay (standardized mean difference: -0.35 days, 95% CI: -1.68 to 0.98 days, P = .61, I² = 0%) and the risk of having postoperative in-hospital mortality (odd’s ratio: 1.07, 95% CI: 0.43–2.63, P = .89, I² = 54%) between these 2 groups were observed. Quality assessment revealed high risk of bias and significant data heterogeneity (I²>50%) in most included RCTs. Conclusion: Preoperative protein-based oral nutrition supplements exert beneficial, but limited, effects on postoperative outcomes in geriatric patients with hip fracture undergoing surgery.