Rationale: Physical restraints are used liberally in some intensive care units (ICUs) to prevent patient harm from device removal or falls. Although the intention of restraint use is patient safety, their application may inadvertently cause physical or psychological harm. Physical restraints may contribute to post-traumatic stress disorder (PTSD), but there is a paucity of supportive data.Objectives: To investigate the association between physical restraint use and PTSD symptoms in ICU survivors. Secondary objectives were to examine the cognitive and physical outcomes associated with physical restraint use and to assess interventions that may be effective in reducing restraint use.Methods: A systematic review of English language studies in PubMed, Medline, Embase, CINAHL, and CENTRAL between January 1, 1990, to February 8, 2020 was performed. Observational or randomized studies that reported on restraint use and associated outcomes, or interventions to reduce restraint use, in critically ill adult patients were identified. Two independent reviewers completed the review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines.Results: We identified 794 articles, of which 37 met inclusion criteria and were included. Thirty of these studies related to patient outcomes including PTSD, delirium, mechanical ventilation hours, and physical injury. Seven related to interventions to reduce physical restraint use. The quality of studies was not high; only four of the included studies were assessed to have a low risk of bias. Three studies found a significant relationship between restraint use and PTSD, but their results could not be pooled for analysis. Pooled data indicated a significant association between physical restraint use and delirium (odds ratio [OR], 11.54; 95% confidence interval [CI], 6.66-20.01; P < 0.001) and duration of mechanical ventilation (mean difference in days, 3.35; 95% CI, 1.95-4.75; P < 0.001). We also found that interventions, such as nursing education, may effectively reduce restraint use by approximately 50% (OR, 0.48; 95% CI, 0.32-0.73; P < 0.001). The impact that a reduction in restraint use may have on associated outcomes was not examined.Conclusions: Physical restraint use may be associated with PTSD in ICU survivors and is associated with delirium and longer duration of mechanical ventilation. Nurse education is likely effective in reducing rates of physical restraint among ICU patients.