National Information Center on Health Services Research and Health Care Technology (NICHSR)
Health Economics Information Resources: A Self-Study Course
Module 2 - Sources and Characteristics of Information Relating to Health Care Financing in the US
Recapping Module 2: International comparisons
In summary, the introduction to the OECD, Health at a Glance 2001 report says it best:
For this reason, care should be exercised before drawing conclusions about variations and trends in the underlying phenomena, especially for comparisons across countries.