title: Risk Factors for Delirium After Spinal Surgery: A Meta-Analysis.
abstract: OBJECTIVE
  Postoperative delirium can occur following various types of surgeries. The specific risk factors for delirium following spinal surgery have not been systematically evaluated. The aim of this study is to conduct a meta-analysis of the risk factors for delirium after spinal surgery.
  
  
  METHODS
  PubMed, EMBASE, the Cochrane Library, and Science Citation Index were searched from inception to October 2014 for original research studies. Relevant studies on patients with delirium following spinal surgery were included if they identified at least 1 risk factor as being associated with delirium. The Newcastle-Ottawa Scale (NOS) was used for the study quality assessment, and the pooled odds ratios (ORs) were used for determining the risk factors.
  
  
  RESULTS
  Six articles met the inclusion criteria. Twenty-four risk factors in the multivariate analyses and 22 factors in the univariate analyses were significantly associated with delirium following spinal surgery. In the pooled analyses, age >65 years (OR: 6.13; 95% confidence interval [CI]: 5.75, 6.54); female sex (OR: 1.21; 95% CI: 1.15, 1.28); number of medications (mean difference [MD]: 1.36; 95% CI: 0.73, 2.00); low preoperative hematocrit (MD: -1.67; 95% CI: -2.97, -0.38) and albumin (MD: -0.33; 95% CI: -0.53, -0.13); duration of surgery (MD: 35.79; 95% CI: 1.42, 70.16); intraoperative blood loss (MD: 124.44; 95% CI: 100.03, 148.85); low postoperative hematocrit (MD: -2.58; 95% CI: -3.70, -1.46), hemoglobin (MD: -1.10; 95% CI: -1.86, -0.35), and sodium (MD: -2.97; 95% CI: -5.42, -0.51); and postoperative fever (OR: 4.52; 95% CI: 2.94, 6.95) were significantly associated with delirium.
  
  
  CONCLUSIONS
  Several risk factors were consistently associated with delirium following spinal surgery, which can be used to identify high-risk patients. Recognizing these patients is important for physicians to develop preventive strategies to reduce postoperative delirium and its negative consequences.
authors.affiliation: Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Changgui
authors.initials: C
authors.lastname: Shi
authors.affiliation: Department of Spine Surgery, Lanzhou General Hospital of PLA, Lanzhou, China; Department of Orthopaedics, Shanghai First People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
authors.forename: Chengwei
authors.initials: C
authors.lastname: Yang
authors.affiliation: Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China. Electronic address: gaoruispine@126.com.
authors.forename: Rui
authors.initials: R
authors.lastname: Gao
authors.affiliation: Department of Spine Surgery, Changzheng Hospital, Second Military Medical University, Shanghai, China. Electronic address: wenyuanspine@gmail.com.
authors.forename: Wen
authors.initials: W
authors.lastname: Yuan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003693:Delirium / Q000453:epidemiology* / Q000209:etiology* / Q000523:psychology; D006801:Humans; D019635:Neurosurgical Procedures / Q000009:adverse effects*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000523:psychology; D012307:Risk Factors; D013131:Spine / Q000601:surgery*
keywords: Delirium; Incidence; Risk factor; Spinal surgery