Our study should be interpreted in the context of several limitations. First, although GWTG–R offers a unique opportunity to study the hospital policy allowing for FPDR, it is a voluntary registry that may not be representative of all hospitals. Second, the limited number of hospitals with an FPDR policy may have lowered our power to detect a potential association between outcomes and a hospital’s policy for FPDR. However, the GWTG–R affords the largest registry of FPDR policy data available in the United States. Third, we recognize that many hospitals may interpret and implement the policy for FPDR in different ways. This variation in practice, along with the fact that a policy may only have been recently implemented, may affect the degree to which a hospital integrates families into the resuscitation itself and influence actual mechanics of the resuscitation