  Objective: To estimate the relationship between a hospital data breach and
hospital quality outcome
  Materials and Methods: Hospital data breaches reported to the U.S. Department
of Health and Human Services breach portal and the Privacy Rights Clearinghouse
database were merged with the Medicare Hospital Compare data to assemble a
panel of non-federal acutecare inpatient hospitals for years 2011 to 2015. The
study panel included 2,619 hospitals. Changes in 30-day AMI mortality rate
following a hospital data breach were estimated using a multivariate regression
model based on a difference-in-differences approach.
  Results: A data breach was associated with a 0.338[95% CI, 0.101-0.576]
percentage point increase in the 30-day AMI mortality rate in the year
following the breach and a 0.446[95% CI, 0.164-0.729] percentage point increase
two years after the breach. For comparison, the median 30-day AMI mortality
rate has been decreasing about 0.4 percentage points annually since 2011 due to
progress in care. The magnitude of the breach impact on hospitals' AMI
mortality rates was comparable to a year's worth historical progress in
reducing AMI mortality rates.
  Conclusion: Hospital data breaches significantly increased the 30-day
mortality rate for AMI. Data breaches may disrupt the processes of care that
rely on health information technology. Financial costs to repair a breach may
also divert resources away from patient care. Thus breached hospitals should
carefully focus investments in security procedures, processes, and health
information technology that jointly lead to better data security and improved
patient outcomes.
