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Thread: Response: How one surgeon discusses BrAIST

  1. #31
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    Quote Originally Posted by flerc View Post
    I should to do the probabilistic calculus but according the number of cases.. I suppose not lessser the 90%. I have also some data and is the 100%
    Guess again.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
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    "We are all African."

  2. #32
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    Quote Originally Posted by Pooka1 View Post
    May not need to repeat it If the long term
    One possible misconception I see cropping up about the BrAIST study is that following these kids for a few years is likely to change *the relationship* between what's seen in the braced and unbraced kids.

    So, I hear things about how we might evaluate the effectiveness of bracing differently if two years down the road some percentage of braced kids in the study go on to need surgery.

    However, there's no reason to think that the braced kids are going to advance to surgery at a *greater* pace then the unbraced kids. In fact, quite the opposite. Half of the unbraced kids advanced to surgery at study end compared to just 3% of those wearing the brace as prescribed. I don't love engaging in examining data not in evidence, but there's every reason to think that, if these kids do advance to surgery in the next few years, they'll advance at roughly the same relative rate as they're advancing now. That is, the kids advancing to surgery over the next few years are likely to come disproportionately, from the unbraced group.

    So, while continued data from this study may (slightly) effect the perceived effectiveness of bracing, it's far more likely to lower the overtreatment numbers as we see how many of these unbraced kids end up on the operating table at or near maturity. Just plugging in the most extreme numbers - if both the unbraced and 18-hour braced kids advance in the next few years exactly as they advanced within this study, in two years the total percentage of these compliant braced kids advancing to surgery will be 6% (3% of the remaining 97%) while 75% of the unbraced kids (50% times the remaining 50%) advance. Again, totally made up numbers, but numbers at least keeping proportionally to the information at hand. Given this expectation that the kids will advance in the future in the same manner that they're advancing now, I can't see how this future data would totally change our evaluation of bracing's effectiveness.

  3. #33
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    Here's a graph that I would like to see that I expect would open up some minds...

    Plot ALL 116 kids where they have average brace wear data. So 116 data points. No summary stats.

    X-axis -> average brace wear
    Y-axis -> final curve measurement at 75% - 100% of growth completed.

    Given the errors bars on the original graph, the scatter on this will be blinding, And we can instantly get a good idea of where these curves are ending up at maturity at least.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  4. #34
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    Quote Originally Posted by Pooka1 View Post
    Here's a graph that I would like to see . . Given the errors bars on the original graph . . .
    Correct, we don't have that data. Nor do we have a graph showing the success rate of the unbraced kids.

    But we *do* have a table of success percentages with error bars.

    And what we can see from that is that there is *no* overlap between the success rate of the kids wearing their braces at least 13 hours a day (the right half of the graph) and those kids wearing their brace less than 6 hours a day (the left quarter of the graph).

    So, what we can say:

    If you wear your brace 6 hours or less (and I think most of these kids are "or less") you have a roughly 25 to 60% chance of avoiding surgery, with the most likely outcome being a 40% chance of success.

    If you wear your brace 13 hours a day or more, you a 70% to 99% chance of successfully avoiding surgery, with the most likely outcome being a 90% chance of success.

    Again, I do not understand all the time spent imagining data which is not in the report. Obviously, that data is not available. Why not focus on the data which *is* there?
    Last edited by hdugger; 01-13-2014 at 05:38 PM.

  5. #35
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    Medians versus averages. If those 29 points in each quartile are not normally distributed then median is correct. That might change some hearts and minds.

    One s.d. = only about 68% of the variability. If you expand to include 95% (two standard deviations) then they would overlap. You are missing about one third of the variability by only showing one s.d..

    And it's not avoidance of surgery, is <50* with up to 25% of the growth remaining. So a 49* with 25% of growth remaining would be a "success". Outside of BrAIST, who considers that a success?

    What you are missing is that the data can legitimately be plotted a number of ways that may or may not lead to the same confidence. In my own work, I choose one way or others for a reason. These authors are doing that too. There is nothing nefarious in that.

    Instead of summary stats, I would just like to see the raw data plotted. I think it would be interesting. It would show the range in "successes" given a particular average hour of brace wear, something a kid needs to know in deciding how much time is worth it.
    Last edited by Pooka1; 01-14-2014 at 06:14 AM.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  6. #36
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    Quote Originally Posted by Pooka1 View Post
    In my own work, I choose one way or others for a reason. These authors are doing that too. .
    My sense is that the graph comes directly from the design of the experiment. Specifically, there was a lot of talk in the bracing research, before this study, about how we had to not just focus on how many degrees kids progressed (what had been shown in most of the previous studies) but in how this played out in terms of whether or not the kids progressed to surgery.

    So, I assume, in response to *that* concern coming from the scoliosis medical community, they designed *this* study to look specifically at success (which they defined as avoiding surgery by study end).

    So, while I get what you're asking, there are lots of studies (in fact, *most* of the bracing studies) which do what you ask. They say how many degrees these kids progress in brace. The most commonly reported number I've seen is 6 degrees. The other thing you ask for - the end point - is not as useful, in my opinion, because it depends so much on the starting curve. If I have a kid with a 25 degree curve, what I want to know is where *my* child will end up, not where lots of kids starting with lots of different curves will end up.

    But, anyway, what we'd like to have a study focus on is no nevermind. This study is what this study is. The focus on surgical success was deliberate. It wasn't some mistake on the part of the authors, or some afterthought in how to present the data - it is specifically what they set out to study. And then they chart that. To me, it's all in keeping - what they want to achieve, what they do, and how they report it.

  7. #37
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    There are many ways to graph those data to address those exact hypotheses. This is what I am trying to get across. Various ways emphasize various aspects of the data.

    I am waiting for subsequent publications. These will certainly have some graphs I am talking about.

    Choices were made. Many choices. I don't know how else to state this. Ask any experienced researcher about this and they will reel off the choices if you tell then the study design.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  8. #38
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    Quote Originally Posted by Pooka1 View Post
    Choices were made. .
    My point was that the data display you were asking for - the end curve at the end of the study for every participant - would not more clearly address the central question of this study. It would be a poorer way of answering the question *these* researchers were looking at.

    Beyond that, yes, I'm familiar with the choices made in putting together a medical research paper. The same choices are made in *every* research paper we've ever discussed on this forum. It's nothing unique to bracing, this study, these researchers, etc. Hence why I keep asking why it's necessary to (continually) discuss the choices made in *this* study. It might leave someone with less experience in research wondering if this study is some special case. To which I'd respond, No. It's not. It's the same as any other study, except that I think it's actually somewhat better thought out, designed, and analyzed, and reported then most other medical studies.

  9. #39
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    There is nothing special about this study apart from other studies. Many choices are available for graphing. They all address the hypotheses.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  10. #40
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    There are things you can measure but, without ancillary information, are ultimately uninterpretable. Not knowing the final curves nor the long term makes these numbers hard to interpret.

    Also, if I was a child, I would want to see all the variability and not just 68% of it.

    The data a child would want to see and the data a researcher shows in a publication are not necessarily the same.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  11. #41
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    Quote Originally Posted by hdugger View Post
    Hence why I keep asking why it's necessary to (continually) discuss the choices made in *this* study. It might leave someone with less experience in research wondering if this study is some special case. To which I'd respond, No. It's not. It's the same as any other study, except that I think it's actually somewhat better thought out, designed, and analyzed, and reported then most other medical studies.
    I thought the follow up was more extense and the sample greater, but I'm not sure really . Even I saw other studies showing a greater succesful percentaje, but I believe the variable values as kind of brace, time in brace, reduction in brace.. were almost the same in all cases of those samples, something not happening in this study.
    Anyway the conclusion about 50% effectivenes is right (under the study conditions) and is what parents should to know and of course is what brace haters here cannot accept.. hence it seems they wants this empty discussion never end..a good way to confuse parents.

  12. #42
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    Quote Originally Posted by Pooka1 View Post
    Not knowing the final curves nor the long term makes these numbers hard to interpret.
    I'm not certain that I find it hard to interpret. It addresses one of the burning questions we've had about bracing - does it work or will the positive results we've seen disappear as soon as we randomize the patients. The answer to that question is now in - yes, the positive results we've seen were actually due to the brace.

    Because we *can* interpret the data to answer that question, we have a tendency to rush forward to all those other questions that we've been (largely) ignoring while we worked out the effectiveness. You've raised some of them here. But I didn't really expect this study to address all of those questions. I see it more as the gate we've been waiting behind. Now that that gate is open, we can go on to really pin down which kids benefit, how we can keep the curve as small as possible, how other more tolerable braces stack up, and so on. So, for me, this just answers the preliminary question, and now we can go on, with other studies, to work out the rest of this.I don't expect that this study will answer these questions, even with more data points and a longer time frame. But I think those answers will come from future studies.

  13. #43
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    Quote Originally Posted by Pooka1 View Post
    You are missing about one third of the variability by only showing one s.d.. .
    One SD is the accepted standard. You're not trying to map all of the data - you're just giving a measure of variability around the mean.

    On the rest, I believe we talked in depth about their study design before they started collecting data. I don't recall much resistance at that point to their measure of success. So, I'm resistant to complaints about this measure which only surface after the study is done.

    Whatever their measure of success, it applies to the unbraced controls as well. So, it's the exact same measure being used in the discussions about over treatment.

    I'll note that, again, that the measure of success in surgery is walking out of the hospital a few days later. I suspect that that, also, is not what a teen might think of as success, but it is how it is measured in the research.

  14. #44
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    Quote Originally Posted by hdugger View Post
    One SD is the accepted standard. .
    You completely missed the point.
    Sharon, mother of identical twin girls with scoliosis

    No island of sanity.

    Question: What do you call alternative medicine that works?
    Answer: Medicine


    "We are all African."

  15. #45
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    Back to the opening quote (in the other topic, where I couldn't post)

    Here's Dr. Hey's headline about the BrAIST study:

    "Are Scoliosis Braces Adolescent Idiopathic Scoliosis Effective for Stopping Curve and Preventing Surgery? New Weinstein Randomized Control Trial Published Today NEJM and Presented at SRS says "YES!""

    And that simple "yes, they're effective" is exactly what I've seen from every other expert commenting on this report. That's the take-away, amongst orthopedic surgeons.

    I'll just note that nowhere in any response I've seen to the report, from Dr. Hey or any other expert, are people suggesting that the effectiveness numbers *in the windows where effectiveness is measured* are going to change. The only place where I've seen that aspect of the report questioned is in these discussions. Given that - given that the numbers show effectiveness and that every expert I've read says that the study showed effectivenss - I'm going to accept that conclusion. Should some other study come down the road that shows something else, I'll re-examine that conclusion. But there is nothing in the study or in the expert response to the study that would lead me to any other conclusion.

    The only other topics I've seen the experts talk about are: overtreatment (from most experts), long-term effectiveness (from Dr. Hey). But the central finding of the study - that braces are effective in keeping teens off of the operating table - has been accepted by every expert I've read.

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