ObjectiveTo systematically review the efficacy and safety of operative treatment versus nonoperative treatment in patients with adult spinal deformity (ASD).MethodsPubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, WanFang Data, and CQVIP databases were searched for controlled studies about operative treatment versus nonoperative treatment for ASD published up till June 2019. ClinicalTrials.gov was searched for grey literatures informally published up till June 2019. Two reviewers independently screened literatures, extracted data, and assessed risk of bias. Meta-analysis was performed by using RevMan 5.3 and Stata 14.0 softwares.ResultsA total of 10 non-randomized controlled studies were included, including 1 601 patients. The pooled results indicated that the operative group was superior to the nonoperative group in ability improvement [the increment of Scoliosis Research Society-22 score: weighted mean difference (WMD)=0.70, 95% confidence interval (CI) (0.69, 0.70), P<0.000 01; the decrement of Oswestry Disability Index score: WMD=11.12, 95%CI (10.74, 11.50), P<0.000 01], pain relief [the decrement of Numeric Rating Scale score: WMD=3.25, 95%CI (3.16, 3.35), P<0.000 01], and Cobb correction [WMD=14.06°, 95%CI (13.60, 14.53)°, P<0.000 01]. The incidence of complications was higher in the operative group than that in the nonoperative group [relative risk=5.38, 95%CI (3.67, 7.88), P<0.000 01].ConclusionsSurgery shows superior efficacy on ability improvement, pain relief, and Cobb correction compared with nonoperative treatment in ASD patients, though its incidence of complications is high. Nonoperative treatment is also an effective treatment for patients with poor physical condition and intolerance to surgery. Due to the limited quantity and quality of included studies, more high-quality studies are required to verify the above conclusions.