UK's hospitals fare no better in terms of cybersecurity. This is about the culture of nursing / doctors / hospital administrators, which is largely shared between USA and UK.
This isn't a systemic issue that is solved by nationalizing health care like UK did.
USA health care system, culturally, is about saving lives. Whether our system matches it is another story. But the underlying people largely do the right thing.
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I think the systemic issues regarding health care / infrastructure / investments are wholly independent of this cybersecurity issue.