Borders make studies like this difficult to do
Studies comparing the two health systems are difficult to do because laws governing privacy effectively bar sharing patient data across international lines. However, this study was made possible because teams of collaborating investigators worked separately to analyze similar questions on each side of the border. The final analysis was completed using the findings of the HICOR team led by Shankaran and a BC Cancer Agency team led by Dr. Hagen Kennecke, who is now Medical Director of the Floyd & Delores Jones Cancer Institute at Virginia Mason in Seattle.
“The raw data never crossed the border,” said Kennecke. “It was never mixed.”
A Canadian oncologist now working in the U.S., Kennecke was careful not to judge whether one system was superior to the other. “Both systems work,” he said. “Patients are getting treated and surviving much longer than they used to. The U.S. system is more expensive and treats more patients. One system is more cost-effective than the other. We can learn from each other.”
Younger patients in the American cohort
Canadian researchers pulled data from 1,622 patients from the entire province of British Columbia diagnosed with metastatic colorectal cancer between 2010 and 2012. The American team used a smaller number of patients (575) who entered chemotherapy treatment between 2010 and 2016, and lived in 13 Western Washington counties. To assure similar cost comparisons, the team converted all cost data from both countries into U.S. dollars as valued in 2009.
The Washington patients were somewhat younger than the Canadian cohort because the HICOR researchers, at the time the analysis was done, did not have access to U.S. Medicare data. Instead, they relied on claims data from two large private insurers, Premera Blue Cross and Regence Blue Shield, which only had data for Medicare patients who also had Medicare supplement policies.
The researchers acknowledge that differences in median age (66 for Canadians, 60 for Americans) might have had subtle effects on direct comparisons of the two populations, so they are continuing to work on the project. The HICOR team now has access to the Medicare data, and will submit the results of their next analysis for publication in a peer-reviewed academic journal.