Measuring hospital quality remains challenging, despite numerous public efforts. Inpatient mortality represents one measure of hospital quality. Researchers sought to assess the association between alerts generated by the Imperial College Mortality Surveillance System (a national hospital mortality surveillance system that generates monthly mortality alerts) and trends in the relative risk of mortality across National Health Service hospital trusts. On average, mortality risk decreased after a trust received a mortality alert. However, the authors conclude that random variation could account for the alerts and that a causal relationship cannot be determined. A past PSNet perspective discussed the use of risk-adjusted mortality as part of a safety measurement program.