Monday, March 26, 2012

How will DSM 5 affect autism rates?

In January, at a meeting of the Icelandic Medical Association, Yale researcher, Dr Fred Volkmar gave a presentation of data from a study looking at the implications of changes to autism diagnostic criteria in DSM 5. His conclusion was that many people who are currently diagnosed with autism, Asperger's, or PDD-NOS would not meet the new proposed criteria for autism spectrum disorder in DSM 5.

Volkmar's remarks were picked up by the New York Times, who ran with the lede:
"Proposed changes in the definition of autism would sharply reduce the skyrocketing rate at which the disorder is diagnosed and might make it harder for many people who would no longer meet the criteria to get health, educational and social services"
Not surprisingly, the article caused much consternation in autism circles. But because the study itself hadn't been published, members of the DSM 5 Neurodevelopmental Work Group, charged with implementing these changes, were unable to pass comment.

After all the brouhaha, the Yale study, with Dr James McPartland as first author, was finally published online two weeks ago - to suprisingly little fanfare. It was also accompanied by a commentary from Susan Swedo and members of the DSM 5 group, who had finally got hold of the paper.

DSM 5 and autism

A quick recap. There are essentially two big changes on the cards in DSM 5 as far as autism is concerned. First, rather than there being separate diagnoses of autistic disorder, Asperger's syndrome, and PDD-NOS, there will be a single category of "Autistic Spectrum Disorder".

Second, rather than organising the criteria into three themes, DSM 5 will collapse that down to two.

But there's also a more subtle and potentially more important change. DSM IV took a kind of pick'n'mix approach, with over 2000 combinations of 12 "symptoms" that would get you a diagnosis.
In DSM 5, this is simplified. The "symptoms" themselves are each somewhat broader and perhaps more flexibly interpreted, but there is much less scope for picking and mixing.

McPartland et al.'s study

Whether or not you agree with the changes in principle, what really matters is how the new criteria translate into the real world. There are currently ongoing "field studies" that are testing out the new criteria to see how they work in practice. McPartland and Volkmar essentially took a short cut by reanalysing the data from a similar field trial conducted 20 years ago when DSM IV was being developed.

To do this, McPartland et al had to translate the questions that were asked in the original study into something approximating an item in DSM 5. They then reanalysed the data, applying DSM 5 rules to "re-diagnose" the kids in the original study.

This is how things worked out. Kids in blue (ASD+) were those who met criteria for ASD in DSM 5. Those in red (ASD-) failed to meet the criteria.




As you can see, roughly three quarters of kids originally diagnosed with autistic disorder met DSM 5 criteria for ASD. However, only a quarter of those with a diagnosis of Asperger syndrome or PDD-NOS made the grade, so to speak.

These figures seem to back up Volkmar's claim that many people, currently diagnosed, would not meet the new criteria. However, with publication, the limitations of the study are now clear, as noted in the commentary by Swedo and colleagues, and by the authors themselves.

Limitations

The most obvious problem is that the original study was not designed for these purposes. While some of the DSM 5 criteria mapped neatly onto items in the original study, others didn't. For example, DSM 5 includes this pretty vague statement:
Symptoms must be present in early childhood (but may not become fully manifest until social demands exceed limited capacities).
Translated into English, this I think means that parents should be able to look back with hindsight and  recognise early signs of ASD, even if they missed them at the time. Quite how this will be ascertained without asking leading questions is not clear. But the important point is that there was nothing in the DSM IV questions that really corresponded to this question, so McPartland had to go with the nearest thing, which was "onset before 36 months".

As Swedo et al caution, it's probably best to wait until the results of the actual field studies are in. However, given that the DSM 5 criteria are much more prescriptive than those for DSM IV, we have to expect results along these lines. 

Further comment comes from David Skuse. Writing in his editorial capacity, he highlights the pressing issue of the people who don't meet the DSM 5 criteria. As mentioned in a previous post, DSM 5 is set to introduce a shiny new diagnostic category of "Social Communication Disorder" which would capture many of these people. The clinical and scientific merits of this new diagnosis are, however, yet to be established.

For me, this all highlights the inherent circularity and subjectivity of the DSM 5 debate. McPartland et al. effectively use DSM IV diagnoses as the standard against which to judge DSM 5. In the original trial 20 years ago, these would have been judged against DSM III. Inevitably the outcomes are slightly different, but who is to say which is better or worse? Swedo et al. make precisely this point, arguing that the true "gold standard" is expert clinical opinion. Or, to put it another way, we know it when we see it. An admission, perhaps, that autism defies definition.




Reference:

McPartland, J., Reichow, B., & Volkmar, F. (2012). Sensitivity and Specificity of Proposed DSM-5 Diagnostic Criteria for Autism Spectrum Disorder Journal of the American Academy of Child & Adolescent Psychiatry, 51 (4), 368-383 DOI: 10.1016/j.jaac.2012.01.007


Related posts:

Further reading:


29 comments:

  1. Thank you Jon for an informative summary of a discussion most parents won't be able to access. A very telling final sentence...

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    1. Thanks Sue. I was actually writing something about the "essence" of autism before I got hold of the paper. But I'll save that one for next week!

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    2. Agape Autism is a site about the causes and treatment of autism. The purpose of the site is provide parents with information on how to treat autism with a natural approach.

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  2. Good post. Clearly I've not been paying attention as this is the first I'd heard of "Social Communication Disorder".

    That seems like a huge deal. And maybe not a good one.

    Inevitably, that category is going to become the "kindof ASD but not very" 'consolation prize' as it were. Whether or not it's intended that way, it will do.

    But that opens a big can of worms because by DSM-V's definition "SCD" is not an ASD but it will be applied to people who have a lot in common with people with an ASD, so it will become a political minefield given that current services are generally geared to helping people with an ASD.

    And I doubt many of them will decide to broaden their remit to ASD + SCD.

    "SCD" may therefore become (or be perceived as - which is the same thing - this is all about perception) a kind of "Not Welcome Here" stamp when it comes to services etc.

    "Sorry, your son can't come to our school, he's SCD not ASD"

    That is going to be a huge problem for some people.

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    1. P.S. You might say "Ah, but we already have that problem, in terms of people who don't get an ASD diagnosis".

      But "SCD" would make matters worse because it would provide a diagnosis for people who clearly are abnormal enough to 'need some kind of diagnosis', but not autistic enough to get an ASD diagnosis.

      At the moment, I suspect that most of those people get an ASD diagnosis eventually, if their parents push hard enough. After all, they need a diagnosis, and ASD is the only one in question.

      But as soon as you introduce "SCD", those people will get diagnosed SCD and the door to ASD services will be barred. So I think this does introduce a new issue.

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    2. I think you're absolutely right. As Liz Ditz mentions below, there's going to have to be a new fight to get services for SCD because no education or health authorities or insurance companies currently have any requirement to do anything about it. In many places, there may be less "coverage" for Asperger's or PDD-NOS but at least there is something.

      From a scientific point of view, I think the changes have some merit, although I tend to go along with David Skuse's view that a better approach would be to define autism purely in terms of social impairment - and then do some research to see whether other characteristics such as the presence or absence of repetitive behaviours really do make for meaningful subgroups.

      As it is, the Work Group have decided that there's no evidence for an autism vs Asperger's distinction so abandoned that (fair enough), but replaced it with a different distinction for which the evidence is equally limited.

      Bottom line though, DSM should be about clinical needs and a pragmatic approach to allocating limited services. Research should be independent of the arbitrary but necessary clinical guidelines. Trying to satisfy both needs at once is a recipe for chaos. In my non-expert opinion.

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    3. To play the devil's advocate here, since SCD is basically autism without the communication issues and without the restricted/repetitive behaviors (and everything that goes with it), are full autism services really appropriate?

      If a child mainly has social issues, do they really need ABA, speech, OT/PT, and specialized classrooms or are those extremely limited resources better used for children who require far more support? Wouldn't it be better if children with SCD received services that focused on their specific problems?

      I really get that you have to fight to get services for your children, been there, done that. But pushing a group of children into a diagnosis that isn't applicable that doesn't have services that are appropriate for them doesn't do them that much good and actually does do a great deal of harm to the children who are more disabled. That's how you get parents advocating against each other even though they are talking about what is supposed to be the same condition.

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    4. MJ: Sure. I agree. Actually I wasn't saying that I personally think SCD will be a bad thing. What I mean is, a lot of people will see it as a bad thing, if they want ASD services, and find that the SCD label is used as a way of keeping them out. Which I think will happen, whatever the intention, just because that's how institutions work.

      It'll be especially disruptive to people who have an established DSM-IV diagnosis of ASD and find themselves reclassified as SCD - what will happen to them? Will they be de-diagnosed? That could be very disruptive indeed and a lot of people would really resist that possibility.

      So I can see stormy weather on the horizon.

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    5. I don't know what will happen to people with an existing ASD diagnosis but I suspect that they will keep it. I don't see a concerted effort being made to go back and re-diagnosis every child with autism.

      I also don't see schools re-evaluating all of their students - at least not in the US. There are very specific rules that have to be followed for that process and I don't think that educators will be in any rush to push children with SCD out of special education.

      I think the real problem is going to be children who don't yet have a diagnosis might get pushed into SCD and then those parents are going to have to fight for services.

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    6. I agree with both of you! I'm the mother of 2 mildly autistic children--now 10 and 8 (diagnosed at 2 1/2 and 3 1/2 respectively), who I feel, the SCD dx is much more indicative of their issues than an ASD dx.

      I too wonder, if in the interim, while everyone sorts out who is truly eligible for ASD related services, and whether or not insurance will cover certain services, if children such as mine will be "grandfathered" in for a certain time period, or until they reach a certain age--such as 12 or 14, the age when children diagnosed with autism often split into different academic tracks--college prep and VoTech/Life Skills,to avoid falling through the cracks.

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  3. SCD is probably also going to encompass the broader autism phenotype (BAP). Lisa Jo Rudy also discussed it:
    http://www.authenticinclusion.org/2012/01/redefining-autism-redefining.html

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    1. I don't think it's clear what SCD is going to encompass. McPartland et al say they couldn't look at it because the criteria haven't been made known yet.

      Thanks for the link. I've added it to the bottom of the post.

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  4. Thank you Jon, this is very clear.

    Autism is a category under the Individuals With Disabilities Education Act (IDEA), the American law mandating services for children with disabilities. But SCD? Nope. And who knows how long it will take to get SCD in.

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  5. DSM5 is not the only diagnostic manual up for major revision. The World Health Organization's ICD (International Classification of Disease) mnaual is under revision and Sir Michael Rutter heads the ICD11 working group omn autism.

    DSM and ICD have always agreed to publish the same diagnostic criteria for autism. ICD is used just as frequently as the DSM and in many areas in the world is considered more as the defining manual than the DSM.

    Sir Michael Rutter has the same reservations about the DSM5 working groups concept and he agrees more with the Yale study criticism of the DSM5 working group.

    If the DSM5 and ICD11 publish differnt diagnostic criteria it will be a dsaster,certainly in terms of research.

    Here's the Rutter interview and exerpt:

    http://www.itasd.org/index.php?option=com_content&view=article&id=38%3Amichaelrutterinterview&catid=8&lang=en

    'GH: How may the changes to DSM and ICD affect future prevalence estimates of ASD?

    MR: The current proposals for DSM-5 would make a huge difference to prevalence estimates of ASD. That is because the field trials analyses undertaken by Fred Volkmar and his research group have shown that the majority of higher functioning cases (such as with Aspergers syndrome) would be excluded. There is a paper on this that is currently 'in press' in the Journal of the American Academy of Child and Adolescent Psychiatry. I hope that these findings will lead to a change of proposal for DSM-V'.

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    1. Thanks RAJ. That's a very good point. I don't think ICD was mentioned in the paper or any of the commentaries / editorials.

      A related issue that McPartland et al do raise is that it's going to be very hard to make comparison between research conducted under DSM 5 and research conducted over the past two decades under DSM IV.

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    2. I don't think difficulty in comparison should be reason not to change. As someone who is undertaking study regarding PDD classifications at present the issue of research comparison has already begun to get murky. The DSM system is very static, but many researchers have begun to reinterpret what is autistic disorder, Asperger's and create 'ASD'. Many using a unique set of criteria. Massive differences also occurred when moving from the DSM III to IV.
      I think that agencies such as the APA and WHO should look to moving towards a Wiki approach which they control, but can be updated, amended or at least provide guidance between major revisions.

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    3. Not a reason in itself, but something to weigh in with all the other considerations.

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  6. The DSM-IV says all PDDs are "severe and pervasive impairment ..." yet the ABS reports that just 74% of people with "autism" (which probably means ASD) in 2009 have severe or profound disability. In 2003, 87% of people with autism had severe or profound disability in 2003 (and the number of people with autism more than doubled from 2003 to 2009). All PDD diagnoses are meant to be on Axis I in the DSM-IV ... which relates to needing clinical attention. Does the DSM-IV really allow diagnosis of PDD for someone with a mild or moderate disability?
    Perhaps this aspect of PDD diagnostic criteria is not always understood/recognised.
    Maybe DSM-IV diagnosis is unclear. Maybe a review will tighten up diagnosis for a while.
    I am puzzled by the severity indicators I understand will be introduced (or more widely used) for ASD under the DSM-V. It seems they will be "mild, moderate and severe" ... so there will be "mild ASD" which means "mild severe impairment" ... which doesn't make sense to me. I suspect the severity term would be more accurately "severe, profound and extreme". This would be less confusing for non-specialists.

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    1. Confusing, I agree. I guess all PDDs are severe impairments, but then within that, some case can be "mild" relative to others. You might be interested in this article:
      https://sfari.org/news-and-opinion/viewpoint/2012/how-do-we-measure-autism-severity

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  7. I know I sound like a broken record but when people (McPartland et al, Skuse, commenters on this blog) use the term 'autism' or 'ASD' do they mean the symptoms, or the (unknown) cause of the symptoms, or both?

    Seems to me DSM and ICD deal with behavioural symptoms only. If that's the case, then the issue of what symptoms are allocated what label is pretty academic isn't it? Even if it does have consequences.

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  8. I have the impression that the DSM-like classifications are getting at an impasse precisely because of their behavioural approach. One can't arbitrarily divide or unite a set of behavioural signs, unless you take into account the very reasons of these symptoms, in order to describe a consistent disorder. It seems to me that these reasons can not be of numbers only...

    Besides, as a French citizen, it strikes me to see how this highlights the issues of a different health policy, where parents need an autism diagnosis to have their children taken care of...

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    1. Precisely. On both points.

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  9. The ambiguity of autism defintion is anything but new, In 1965 Leo Kanner write a paper on this very same subject two decades after he published his seminal article:

    'This sage advice was not heeded by many authors. While the majority of the Europeans were satisfied with a sharp delineation of infantile autism as an illness sui generis, there was a tendency in this country to view it as a developmental anomaly ascribed exclusively to maternal emotional determinants. Moreover, it became a habit to dilute the original concept of infantile autism by diagnosing it in many disparate conditions which show one or another isolated symptom found as a part feature of the overall syndrome. Almost overnight, the country seemed to be populated by a multitude of autistic children, and somehow this trend became noticeable overseas as well. Mentally defective children who displayed bizarre behavior were promptly labeled autistic and, in accordance with preconceived notions, both parents were urged to undergo protracted psychotherapy in addition to treatment directed toward the defective child's own supposedly underlying emotional problem.

    By 1953, van Krevelen rightly became impatient with the confused and confusing use of the term infantile autism as a slogan indiscriminately applied with cavalier abandonment of the criteria outlined rather succinctly and unmistakably from the beginning. He warned against the prevailing "abuse of the diagnosis of autism," declaring that it "threatens to become a fashion." A little slower to anger, I waited until 1957 before I made a similar plea for the acknowledgment of the specificity of the illness and for adherence to the established criteria.

    To complicate things further, Crewel, in the hope of avoiding confusion between true autism and other conditions with autistic-like features, suggested the term pseudo-autism for the latter. Even this term came to be employed haphazardly, and conditions variously described as hospitalism, anaclitic depression, and separation anxiety were put under the heading of pseudo-autism'.

    http://www.neurodiversity.com/library_kanner_1965.html

    The more things change the more they stay the same.

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    1. The problem with the criteria for autism is, as far as I can see, that they *haven't* been outlined succinctly and unmistakeably from the beginning. As BlaiseLaPsy points out you can't 'arbitrarily divide or unite a set of behavioural signs, unless you take into account the very reasons of these symptoms'. The signs of autism have broadened in scope and reduced in number as the number of children identified as showing autistic characteristics has increased.

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  10. Yet another analysis of the DSM-5 Autism Do-Over that ignores

    (a)the express exclusionary language of DSM-5 ASD mandatory criterion A:

    ""A. Persistent deficits in social communication and social interaction across contexts, not accounted for by general developmental delays."

    and ignores:

    (b) the fact that the DSM-5 ASD is said to be consistent with current autism research, research which at last two authorities i)Dr. Catherine Lord and ii)Dr Craig Erickson, chief, Christian Sarkine Autism Treatment Center, Indiana University School of Medicine have said demonstrate a bias toward inclusion of high functioning autism subjects and exclusion of intellectually disabled subjects;

    and also ignores

    c) express statements by Dr. Catherine Lord and by Dr. Fred Volkmar (they agree on this point) that the real targets for exclusion from the DSM-5 ASD are at the intellectually disabled end of the Autism "Spectrum".

    "Catherine Lord, the director of the Institute for Brain Development at NewYork-Presbyterian Hospital, and a member of the committee overseeing the [DSM-5 autism] revisions, said that the goal was to ensure that autism was not used as a “fallback diagnosis” for children whose primary trait might be, for instance, an intellectual disability or aggression." [Bracketed terms added for context - HLD]

    - Dr. Catherine Lord, as reported by NYT High Functioning Autism/Asperger's reporter, Amy Harmon, A Specialists’ Debate on Autism Has Many Worried Observers, New York Times, January 20, 2012

    "In its next manual on mental disorders, the American Psychiatric Association plans to issue a single set of diagnostic criteria that will merge the four types of disorders on the autism spectrum, which include autism and Asperger syndrome. Although no current patient will be affected by the new rules, research by Yale Child Study Center Director Fred Volkmar suggests that the revision may disqualify a large number of intellectually disabled patients from receiving a diagnosis of autism spectrum disorder in the future." [Underlining added for emphasis - HLD]

    - Yale Daily News, February 2, 2012

    I hope I have not annoyed or bothered anyone by mentioning the express exclusion of the intellectually disabled, once described by CDC autism expert Dr. Marshalynn Yeargin-Allsopp as autism's vast majority, from the DSM-5 Autism Spectrum Disorder.

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    1. Thanks Harold. I started responding and it turned into a new post (no facility for putting graphs in the comments section). See Autism and intellectual disability in DSM-5

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  11. wow great i have read many articles about this topic and everytimei learn something new i dont think it will ever stop always new info , Thanks for all of your hard work!

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  12. I see from the technical calculations the rationale that some might lose their diagnosis but my sense is that, in fact, more individuals might be diagnosed rather than less under DSM-5, in clinical practice. As it stands, the proposed DSM-5 criteria seem to offer more scope and flexibility for interpretation. For example, the first criterion relating to social communication and social interaction which states "deficits in social-emotional reciprocity; ranging from abnormal social approach and failure of normal back and forth conversation etc" would allow for individuals who only have difficulties with sustaining conversation to "tick that box". Moreover, section B of the proposed criteria regarding restricted, repetitive patterns of behaviour, interests, activities etc has new options included as key symptoms that are not in DSM-IV as key criteria. Specifically, B2 (which refers to difficulty with change in routine) and B4 (which refers to sensory sensitivities), have only ever really been considered "associated" features of ASD not key symptoms. As such, under DSM-5, a child meeting the social interaction criteria would "only" need to present with difficulty with change in routine and hyper-sensitivities (e.g., sensitivity to noise) to access the full diagnosis. In this example, there would be no requirement for evidence of repetitive behaviours, restricted interests or compulsive rituals. Therefore, one might argue that the new criteria might mean that more children would be picked up who until now might have missed out on a diagnosis because they presented with some of these "associated" symptoms.
    Regardless, the sticking point seems to relate to access to funded support for this population. However, in practice, I think that the more important question to ask is actually, exactly what kind of funding would those, once diagnosed with Asperger's or PDD-NOS, really be missing out on if they get relegated to the Social Communication Disorder group? The children who have much lower support needs are frequently the ones we are later in detecting because their presentations are much more subtle as they are usually higher functioning. So, often, by the time they are picked up, they are at an age where early intervention funding no longer applies to them anyway. Within the education system, those with Asperger's or PDD-NOS seem to "get the scraps" when it comes to funded support in the classroom. Currently, if a child with a diagnosis of Asperger's receives one or two hours per week of funded aide time, then they are lucky. Even if they do get funding for that limited support, what does that really translate to in terms of practical help and improved skills or functioning for the child? Often, education settings are not able to provide things like on-site social skills groups or intensive learning support that children with an ASD might need. Alternatively, sometimes, there is also an over-focus on funding for support (e.g., support from a teacher's aide), when the existing class teacher might be well able to accommodate the student without funded support by using common-sense, teaching practices like breaking tasks down into smaller steps, visuals in the room, simplifying instructions etc.
    Perhaps a more pressing issue will be the status of a diagnosis like Social Communication Disorder vs ASD in the medicare system. Assuming that some of those once diagnosed with Asperger's or PDD-NOS might be re-allocated to this diagnosis, what will happen to the support they were able to access via pathways like the current Australian "mental health care plans"? Currently, children with Asperger's (up to 70% of whom present with an anxiety disorder, depending on which prevalence study you read) can receive support from a clinician to manage their mental health difficulties. I am wondering if the same would apply to those who will be diagnosed with Social Communication Disorder.

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  13. In the Education system in which I work we have already noticed diagnostic substitution between ID and Autism. The criteria for enrolment in special schools changed from ID only to include children with a stand alone Autism diagnosis. The result is that far fewer diagnoses of ID are being given to children - the diagnosis of Autism is easier to attain in my State than ID and it now makes no difference to limitations in accessing special schools so why bother?

    This significant diagnositic substitution can be seen in less than 12 months of a funding cycle. It will be interesting to see in my State if students with social communication disorder type profiles all of a sudden start getting diagnosed with IQs in the 68- 71 range.

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