Sarcopenia for outcomes in patients undergoing spinal surgery: A protocol for a systematic review and pooled analysis of observational studies

Background Sarcopenia is a progressive age-related skeletal muscle disorder characterized by decreased muscle mass and loss of muscle function. Recent studies have shown that sarcopenia is able to predict a variety of clinical outcomes after spinal surgery. Controversy still exists among previous reports in terms of the definition and measurement of sarcopenia, these findings are heterogeneous so far. Therefore, the aim of the current study is to assess the up-to-date evidence of sarcopenia for postoperative outcomes among people undergoing spinal surgery. Methods and analysis This protocol was carried out based on the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) statement. It has been pre-registered in PROSPERO with the registration number of CRD42021260459. Three databases (including Pubmed, EMBASE, and Cochrane Library) will be searched from inception through May 10, 2021 to determine related cohort studies examining sarcopenia on multidimensional outcomes in patients undergoing spinal surgery. Major outcomes will be involved including mortality, morbidity, length of stay, postoperative complications or adverse events. DerSimonian & Laird random-effects meta-analysis will be used to calculate pooled odds ratio (OR) for binary data and pooled weighted mean differences (WMDs) or standardized mean differences (SMDs) for continuous data. The Newcastle-Ottawa Scale (NOS) will be used to assess the risk of bias of included studies. Narrative synthesis will be carried out if a pooled analysis is not possible. Ethics and dissemination Ethical approval is not required for this study as the data involved are from the published literatures. We intend to disseminate or share the results of the study in a peer-reviewed journal or at relevant conferences.