There is plenty in the news on recommendations for breast cancer screening, but one detail jumped out at me -- namely, the suggestion that more women aged 40-49 (1904) would need to be screened regularly to prevent one death due to breast cancer, than women aged 50-59 (1339). This gets prominence in news reports because it's an easy way of summarizing effectiveness, even though it's a completely misleading interpretation of the recommendation. From the source material:
Total number to screen to prevent one fatality from cancer:
Ages 39-49: Mean 1904, CI (929, 6378)
Ages 50-59: Mean 1339, CI (322, 7455)
A less-than-compelling difference of effectiveness if one confidence interval lies completely within the other.
The intended point of the recommendation was that screens and operations have risks -- false positive results leading to unnecessary biopsies and unintended consequences -- though on first inspection I couldn't find any data on the mortality risk from overtreatment to compare.
P.S. There's clearly a lot more to say about the implications of this analysis, for the health care debate in the U.S. at least, but I'm in a position at least to dispute one misinterpretation.
Total number to screen to prevent one fatality from cancer:
Ages 39-49: Mean 1904, CI (929, 6378)
Ages 50-59: Mean 1339, CI (322, 7455)
A less-than-compelling difference of effectiveness if one confidence interval lies completely within the other.
The intended point of the recommendation was that screens and operations have risks -- false positive results leading to unnecessary biopsies and unintended consequences -- though on first inspection I couldn't find any data on the mortality risk from overtreatment to compare.
P.S. There's clearly a lot more to say about the implications of this analysis, for the health care debate in the U.S. at least, but I'm in a position at least to dispute one misinterpretation.