Ransomware Attacks, ED Visits and Inpatient Admissions in Targeted and Nearby Hospitals

Ransomware attacks on hospitals involve hackers encrypting computer networks and demanding payment for their restoration, potentially disrupting the delivery of health care services. These incidents have been increasing in the US, especially since the COVID-19 pandemic. Between 2016 and 2021, more than 370 attacks occurred on US clinics, hospitals, and other health care organizations; the number of attacks doubled over this time. Evidence on the health care consequences of these attacks is limited. A study of an attack on 4 facilities found a 15% increase in emergency department (ED) visits in nearby facilities. We analyzed disruptive ransomware attacks against hospitals in California from 2014 to 2020 and ED and inpatient admissions in attacked and nearby hospitals.