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Nov 19, 2009

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Great work and great blog, David. I have linked to it and written about it here: http://runningahospital.blogspot.com/2009/11/evidence-in-medicine.html

Excellent explanation; I found this blog through Paul's link. Don't you think a lot of this firestorm may be from people's fear of how insurance companies may use this information? I don't think insurance companies care a whit about patient's preferences.....

Bev, I agree that at least some of the fear is about what insurance companies will do, and that the insurance companies don't think in terms of patient preferences. At the same time, I think insurers will keep paying for screening mammograms (and screening PSAs) because they would otherwise lose lots of customers.

It's actually the government that has been slowest to pay for screening procedures/tests through Medicare (even the ones that are clearly indicated), though at this point Medicare pays for most reasonable screening.

A comment on my Facebook posting, David, from someone named Gulay:

"The USPSTF takes this into account by recommending against routine mammograms in the 40s, but states that a decision to screen should take consider an individual woman's values. All in all, not that unreasonable a position as far as I'm concerned."
Ok I can agree with this one.

But I definitely have problems with this one:
"The USPSTF recommends against clinicians teaching women how to perform breast self-examination. (Grade D recommendation)".

And other from Sharon:

Thanks so much for the link. It is refreshing - and helpful! - to read a rational analysis from an informed expert.

Thanks for the post! I think you have made a good summary of the issue, and really hit the nail on the head with your re-wordings of the USPTF recommendations. Thanks for your post! I am linking to it in my blog, as I think it is solid!

Nicholas Fogelson, MD

You write about the evidence behind the USPSTFs revised guidelines. Fair minds can hash this out. I was reviled by the suffusion of politics over the issue. This is a glimpse of the obstacles that comparative effectiveness research will face, and they may be insurmountable. While the USPSTF may be imperfect, they're a lot more objective than those who have attacked them. Many of these groups have transparent conflicts of interest on the issue. More thoughts at http://bit.ly/8R0wAx Best of luck on the blog.

The USPSTF states "given that the age groups (40 to 49 years and 50 to 59 years) are adjacent, the Task Force elected to emphasize the mortality outcomes." However, the decrease in mortality cited by the task force is nearly identical (15% and 16%) for these two age groups. Compounding their error, there is no “statistics of adjacency” and the USPSTF fails to describe how "adjacency" of the two age groups leads one to conclude that mortality outcomes is a better measure than life-years gained.
A primary source motivating the USPSTF to alter guidelines states that "conclusions about the optimal starting ages for screening depend more on the measure chosen for evaluating outcomes. If program benefits are measured in life-years, the measure most commonly used in cost- effectiveness analysis, then our results suggest that initiating screening at age 40 years saves more life-years... Starting annual screening at age 40 years (vs. 50 years) and continuing annually to age 69 years yields a median of 33 life-years gained per 1000 women screened. If the goal of a screening program is to efficiently maximize the number of life-years gained, then the preferred strategy would be to screen biennially starting at age 40 years (1)."
Nelson's review, upon which the USPSTF relied to change their recommendations, states that "The ages at which this tradeoff becomes acceptable to individuals and society are not clearly resolved by the available evidence (2)." However, the USPSTF chooses to emphasize the adverse consequences for most women and classifies harms for all age groups as "moderate."
The task force identifies false positives as the major harm in the younger age group. The task force indicates that it requires 565 more mammograms to save a life in the 40-49 year age group as compared to the 50-59 year group. Schell, et al, in evaluating the recall rate for 545,505 examinations in women aged 40-49, found that the rate is on the order of 9% which would lead to a "harm" of approximately 51 instances of additional views and/or ultrasound, 5 percutaneous biopsies under local anesthesia and the discovery of one cancer (at a rate of 3 cancers/1000 mammograms)(3). In order to conclude that the harm overshadows the life saved, the task force must find that the value of a human life is something less than the combined negative value of 616 imaging exams, 5 biopsies under local anesthesia, and the discovery of one new cancer.
In the newly passed Senate health reform bill, the USPSTF has been given a prominent role in determining what kind of care will and will not be allowed in a health care system. Under the new administration, this first effort by the USPSTF does not inspire confidence.
References
1. Mandelblatt JS, Cronin KA, Bailey S, Berry DA, de Koning HJ, Draisma G, et al. Effects of mammography screening under different screening schedules: model estimates of potential benefits and harms. Ann Intern Med. 2009;151:738-47.
2. Nelson HD, Tyne K, Naik A, Bougatsos C, Chan BK, Humphrey L. Screening for breast cancer: an update for the U.S. Preventive Services Task Force. Ann Intern Med. 2009;151:727-37.
3. M. J. Schell, B. C. Yankaskas, R. Ballard-Barbash, B. F. Qaqish, W. E. Barlow, R. D. Rosenberg, and R. Smith-Bindman Evidence-based Target Recall Rates for Screening Mammography Radiology, June 1, 2007; 243(3): 681 - 689.

The USPSTF takes this into account by recommending against routine mammograms in the 40s, but states that a decision to screen should take consider an individual woman's values. All in all, not that unreasonable a position as far as I'm concerned.

The USPSTF may be imperfect, they're a lot more objective than those who have attacked them. Many of these groups have transparent conflicts of interest on the issue. More thoughts at rheumatic fever Best of luck on the blog.

Given the economic reasoning and health care recommendation it is clear that more attention should be paid to further genetic research in order to limit the amount of required mammography and biopsies.

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