In the US, physicians tend to emphasize curative (disease-fighting, life-extending) care. Many American physicians view the death of a patient as a personal defeat. Thanks in large part to numerous advances in medical technology over the past half-century, physicians (worldwide, but especially in the US) have become very good at "keeping people alive." That said, keeping someone alive often comes with a price - namely, the patient's quality of life. Relative to their English colleagues, American physicians are generally more resistant to moving patients from curative care to palliative care - care that focuses solely on reducing/eliminating symptoms. It comes as no surprise, then, that patients with chronic disease are living longer in the US.
Saying that longer lives implies "better" healthcare is naively simplistic at best. That conclusion is indicative of a fundamental misunderstanding of the goals of medical care. The goals of quality health care demand a balance between curative and palliative care. On one extreme end of the curative-palliative-care spectrum you have the physicians (think: Kevorkian) who want to focus solely on reducing symptoms - even to the point of death. On the other extreme of the spectrum you have those who want to extend life at any cost (think: Terri Shiavo case). On this axis, American doctors lean somewhat to the "right" of most doctors worldwide.
The best doctors in any country are straddling the line between "excessive" and "inadequate" care. That being said, conflating palliative care with "giving up" on the patient is an all too common issue among physicians and patients. Though I have full confidence in this research team's statistical results, they (Smith, in particular) seem to be unfamiliar with how heavily differences in culture affect healthcare, especially among patients with chronic diseases.