Become a fan of Slashdot on Facebook

 



Forgot your password?
typodupeerror
×
Math Earth Science Technology

Cervical Cancer Just Got Much Deadlier -- Because Scientists Fixed a Math Error (arstechnica.com) 183

An anonymous reader quotes a report from Ars Technica: Cervical cancer is 77 percent more deadly for black women and 44 percent more deadly for white women than previously thought, researchers report today in the journal Cancer. But the lethal boosts aren't from more women actually dying than before -- they're from scientists correcting their own calculation error. In the past, their estimates didn't account for women who had undergone hysterectomies -- which almost always removes the cervix, and with it the risk of getting cervical cancer. We don't include men in our calculation because they are not at risk for cervical cancer and by the same measure, we shouldn't include women who don't have a cervix," Anne F. Rositch, the study's lead author and an epidemiologist at Johns Hopkins told The New York Times. For the study, the researchers looked at national cervical cancer mortality data collected between 2000 to 2012. They also looked into national survey data on the prevalence of hysterectomies. Then, they used those figures to adjust the number of women at risk of dying of cervical cancer. The researchers found that black women have a mortality rate of 10.1 per 100,000. For white women, the rate is 4.7 per 100,000. Past estimates had those rates at 5.7 and 3.2, respectively. The new death rate for black women in the US is on par with that of developing countries. Though the new study wasn't designed to address racial disparities, experts speculate that the large difference reflects unequal access to preventative medicine and quality healthcare.
This discussion has been archived. No new comments can be posted.

Cervical Cancer Just Got Much Deadlier -- Because Scientists Fixed a Math Error

Comments Filter:
  • by nick13245 ( 681899 ) on Monday January 23, 2017 @10:48PM (#53726157)
    Seems like an obvious error from a statistical analysis standpoint. Makes me wonder how much critical medical research has obvious errors like this.
    • by Anonymous Coward on Monday January 23, 2017 @11:17PM (#53726249)

      Uh, peer review ultimately found and corrected the error....

    • by raymorris ( 2726007 ) on Monday January 23, 2017 @11:17PM (#53726251) Journal

      It seems to me both are true and useful. I would even go so far as to say the original number is more useful.

      1 in X women die from cervical cancer. (old number)

      Of women who did not have a hysterectomy (prior to cancer), 1 in Y die from cervical cancer. (new number)

      Both are true. How might mortality rates be used? One important use is comparisons for policy making decisions:
      10 in X women die from heart disease, 1 in X die from cervical cancer. Therefore, we should invest more prevention efforts toward heart disease.

      Or:

      X% of women die from alcoholism, Y% from cervical cancer. Therefore, we should spend the most money researching cures for ______ ?

      For these policy, questions, we want to know how many people are affected. Period. It's not a useful comparison to say "of people who drink, X die from alcoholism, while of people who have a uterus, Y die from cervical cancer". Those numbers don't give us any useful comparison with which to make decisions. The useful numbers for decision making are "how many people could be helped by addressing this issue?"

      • The useful numbers for decision making are "how many people could be helped by addressing this issue?"

        No, the first and primary useful number consideration is, "Now that we're 20 TRILLION dollars in debt and most new jobs are low-paying junk that barely creates any tax revenue, and we have an exploding entitlement spending problem the mere interest on the debt for which will soon displace nearly all discretionary spending ... what can we afford to research?"

        You want to address the X in Y cases of Z disease in given populations? Return to producing the sort of economic health and largess that allows us t

        • I don't disagree with your general conclusion when it comes to spending that politicians force on us. I don't think my post said anything about government spending, though.

          Howard Hughes Medical Institute has $18 billion dollars, the Kellogg Foundation has $8 billion. Both spend on health / medical programs. I personally decide how to donate my money.

    • Comment removed based on user account deletion
  • by sinij ( 911942 ) on Monday January 23, 2017 @11:00PM (#53726185)
    See? I always told everyone math give you cancer! Now I finally have a proof.
  • Yes we can (Score:2, Insightful)

    by lucm ( 889690 )

    The new death rate for black women in the US is on par with that of developing countries.

    In other news, insurance companies make record profits since Obamacare

  • It sounds like they just divided women into two sub-groups, one of which has a zero risk of getting cervical cancer.

    The overall risk of cancer for women is still the same.

    Depending on what you are using the statistic for (e.g. assessing your own risk of getting cervical cancer, large-scale targeted prevention efforts, allocating government health-care funding based on overall population, etc.), you may find the new set of statistics more useful than the old one, or vice-versa.

    • by Imrik ( 148191 )

      Just nitpicking, these are the stats for death by cervical cancer, not for getting it. If it was for just getting it, including women who've had hysterectomies would have had a far smaller effect as most women don't get a hysterectomy before they get cancer.

      • Most women who get hysterectomies don't get it for cervical cancer. Cancer of the womb or ovaries are the usual reasons, that's why not all hysterectomies even remove the cervix. What this correction does is to take out of the calculation those women who, to prevent/treat a womb cancer had, had a procedure which also removed their risk of cervical cancer. Cervical cancer is often not detected in time for surgical responses, and when responded to surgically is usually not done with a hysterectomy. Why remov

  • Comment removed (Score:5, Insightful)

    by account_deleted ( 4530225 ) on Monday January 23, 2017 @11:24PM (#53726271)
    Comment removed based on user account deletion
    • by zifn4b ( 1040588 )

      Cervical cancer didn't become deadlier, we've just become slightly better informed.

      Nah, just ignore the facts and you'll be more safe! CEO's do it all the time. It really works I tell you! If you claim otherwise, you're just a pessimistic curmudgeon. Gotta stay positive!

  • Before guessing the racial disparity is from unequal access, rule out Vitamin D. Low Vitamin D levels are associated with higher rates of some cancers. Darker skin causes slower Vitamin D production from exposure to sunlight.

    • Re:Vitamin D (Score:4, Insightful)

      by Imrik ( 148191 ) on Monday January 23, 2017 @11:43PM (#53726337) Homepage

      The racial disparity they're talking about in this case is that white women are more likely to get a hysterectomy after they get cervical cancer than black women are. They aren't talking about the overall higher death rate among black women, which could be affected by vitamin D.

      • My reading of the data is that they are publishing the likelihood of any given individual contracting cervical cancer. By removing women without cervixes from the equation they calculated the new incidence among those at risk for the disease.

        They were not looking at relapse rates status-post initial diagnosis and subsequent treatment (which is what you're addressing when you mention hysterectomy status-post initial diagnosis). So whether white women or black women get hysterectomies after their initial diag

        • by Imrik ( 148191 )

          They're talking about the death rate, not the contraction rate.

          • In full, they are talking about those who contract and THEN die. But they specifically are addressing that hysterectomies remove individuals from the denominator of the equation with regard to incidence and subsequent morality. The study has nothing to do with how the cervical cancer, once present, is treated.

            One could hypothesize that the racial disparity has to do with how the african american patients are treated once diagnosed, but since I'm not willing to go through the paywall and see if they controll

  • Cervical cancer didn't get more deadly, statistics have nothing to do with whether or not a certain cancer is more lethal or less susceptible to treatment.

    The statistics also no longer apply to 'just' women, they only apply to women who haven't (yet) had their cervix removed, it's a different subset of people. 1/3 of women get hysterectomies (2/3 of those are deemed to be unnecessary).

    It's not necessarily true that you can't get cervical cancer after a hysterectomy, even with the cervix removed (not necessa

  • "Cervical Cancer Just Got Much Deadlier -- Because Scientists Fixed a Math Error"

    No, it's just as deadly as it always was, it's just being measured more accurately now. The perception of the mortality value changed, but nothing else.

    The headline would have you believe that scientists changed a physical property of the universe because they moved a decimal point or something.

  • by Solandri ( 704621 ) on Tuesday January 24, 2017 @12:33AM (#53726509)
    Article is paywalled so I can't read their actual data. If R is the rate at which women die of cervical cancer, n is the number of women who die of cervical cancer, N is the population of women, and h is the fraction who have had hysterectomies.

    R_initial = n / N
    R_adjusted = n / (N - h*N) = (n / N) * (1 / (1-h))
    R_adjusted / R_initial = 1 / (1- h)
    (1-h) = 1 / (R_adjusted / R_initial)
    h = 1 - 1/(R_adjusted / R_initial)

    For black women, R_adjusted / R_initial = 1.77, so

    h = 1 - 1/1.77 = 0.435

    43.5% of black women have had hysterectomies.

    For white women, R_adjusted / R_initial = 1.44, so

    h = 1 - 1/1.44 = 0.306

    30.6% of white women have had hysterectomies.

    According to this site [nwhn.org] over 1/3 of women over age 60 have had hysterectomies. Which seems to agree with the above calculated rates. I had no idea hysterectomies were that prevalent.
  • Exactly what the Subject says. Cervical cancer did not get deadlier. That would be an adjustment to the 1, 3, or 5 year mortality rates which are not addressed here. What they adjusted was the incidence of the disease, i.e. the likelihood that you will get the disease.

    Their data is valid presumable, but this headline about "deadlier" is wholly inaccurate. Report what the study actually concluded, not clickbait.

    • Their data is valid presumable

      Presumably, you mean presumably! I wouldn't normally bother but it's a weird error I frequently make too. I know the correct spelling, y is not near e, and yet my muscle memory keeps on mistyping it. Do you frequently make this error? I'm glad it's not just me at any rate.

      Brains are weird.

      • No, it was a typo on my phone.

        Also...moderation "off topic"? How is pointing out, and explaining why, that the study doesn't have the conclusion that the headline implies "off topic?"

        Should I have made a butt joke? Is that on topic? Yeesh.

  • by quenda ( 644621 ) on Tuesday January 24, 2017 @01:22AM (#53726637)

    experts speculate that the large difference reflects unequal access to preventative medicine and quality healthcare.

    Which "experts"? Why dismiss all the other cultural and genetic possibilities?
    If it is about "access", why do poor whites have better life expectancy, and why are Hispanics so healthy and long lived in the US?

  • ..(and apparently harder than surgery).

  • First, praise for communicating the error!

    Second, how does such a beginners boo boo slip into statistics? I understand forgetting females without a cervix. But beings that weren't conceived with one? It sort of leaves the impression of botched research. Perhaps the findings and interpretation were rushed out to appease patrons. What else brings back memories of Roquefort and needs a once over? Did they confine the research to humans or more generally to primates?
    So many questions.

  • So they correct the figures by removing women with hysterectomies from the group and the number jumps up, and then they claim that the cause is "unequal access to healthcare" causing higher stats in that group. So I take it the women are getting their uterus and cervix removed by NON health care professionals?
  • "Though the new study wasn't designed to address racial disparities, experts speculate that the large difference reflects unequal access to preventative medicine and quality healthcare."

    This is very strange, because we are spending lots and lots of money trying to get every woman to attend the damn screening (which together with vaccination is the only way to prevent cervical cancer). Do you know how hard that is?

    It's not because of unequal access, it's not because of "muh oppression", it's because we cannot do more than send out invitations, offer self-sampling that can be mailed in, send out a gyno-bus, or offer online/phone consultations. We cannot forcibly make them. Do you have any ot

  • by 2fuf ( 993808 ) on Tuesday January 24, 2017 @06:19AM (#53727257)

    It's a classification error.

  • One of the reasons we get foaming at the mouth antivaxxers is a redefinition of autism a bit over ten years back. The other is to look for something to blame other the cruel and hard reality of genetics.
  • We need not trust ANY data. Even our own. Verify.

  • Does developing nation include third world nations? Does anyone doubt that black people are murdered by our social systems? So let's go have a rally about how America is number one in the world. That's enough to keep CHUMP supporters happy.

So you think that money is the root of all evil. Have you ever asked what is the root of money? -- Ayn Rand

Working...