Restrictive behavioral interventions in acute psychiatric settings have been shown to pose an unknown but potentially fatal cardiovascular risk through a population-based cohort and self-controlled case series study using national clinical registries. Key findings:The safety analysis analyzed a baseline population of 24,423 adult psychiatric patients subjected to either mechanical or chemical restraint procedures. The mathematical risk analysis generated the precise number needed to harm estimate of 548 patients (95% CI, 311 to 1,912). Conclusively, there is a connection between mechanical restraint and high risk of VTE. Venous thromboembolism after mechanical restraint in psychiatric hospitals: population based cohort and self-controlled case series study.