Monday, January 28, 2013

An objective severity scale for sufferers of multisystem neuroimmune diseases

This post introduces an objective severity scale for applicable multisystem neuroimmune diseases.

It is not a replacement for the upcoming MEICC scale (or ICSS), Bell Scale, Karnofsky Scale, Carruthers 2003 symptom scale, Orthostatic Grading Scale, or any other severity scale for diseases. It is not a replacement for a good disease definition or a good biomarker measurement.

It is its own severity scale with a narrow design goal.

Audience

Unlike most, this scale is initially meant for sufferers.

Other uses are not ruled out.

Motivation

The largest motivation is for us to understand one another better, especially in casual online discussions and other places where existing scales (and biomarkers) are impractical.

There are quite a lot of ways this will help us. With better understanding, we can make progress in science, health, and justice. We can help one another better. We will collectively understand the disease better.

The most important part is objectivity.


Objectivity ensures that we are on the same page. I believe that it significantly reduces prejudice and misconceptions.

For example, any two people's definitions of "moderate" (or "severe" or "mild") are quite often vastly different. Yet we use those terms in discussions of science, medicine, advocacy, and more.

As a result, our advice and analyses can be completely off without our realizing it. I believe that they usually are.


This scale is a small step toward objectivity and therefore better understanding of one another at a basic level.

More in future posts.

Design goal

Here is the design goal.


Above all, this scale is meant to be objective.

It is also intended to be (in no particular order and with a couple of redundancies for clarity):

  1. mistake-resistant for fogged people
  2. reliable (test-retest and inter-rater)
  3. short (e.g., contrast with Carruthers 2003 symptom scale)
  4. simple
  5. recognizable (e.g., everybody knows what it means)
  6. meaningful
  7. straightforward
  8. appropriate to the disease1
  9. free of confusion about the meaning of characteristics (e.g., "severe symptoms at rest" in the Bell scale — what does "severe" mean in that sentence fragment?)
  10. free of decisions about the relative priorities of multiple characteristics within a range (e.g., what if you are A but not B? Contrast with Karnofsky and Bell (e.g., "confined to bed or couch most of day; unable to concentrate more than 1 hour per day"))
  11. free from subjective practitioner judgements and influence from misopathy (e.g., "hospital admission is INDICATED" in Karnofsky — who decides what is indicated and by what rules? Will a sufferer or carer know this? Are those rules consistent?)
  12. free of bias due to, for example, the fact that hospitals are more dangerous to sufferers of these diseases than to other diseases (contrast Karnofsky; also remember that different countries have non-comparable rules)
  13. unambiguous
  14. fudge-free
  15. weasel-free
  16. at least slightly resistant to meaning-twisting by denialists
  17. communicable
  18. accessible
  19. usable in online environments including polls and surveys (with software restrictions on number of answers, length of questions, etc.) and with decent binning for histograms (more later)
  20. available without Internet access
  21. translatable into different languages and cultures without loss of meaning (e.g., "severe symptoms at rest" in Bell scale might not translate well to a language that uses different words for severity)
  22. usable in casual environments (minimal effort, immediately available, etc.)
  23. nonproprietary (with full description not modifiable by denialists)
  24. open access and not behind a paywall or requiring registration
  25. possible to reason about mathematically (more later)
  26. reasonably correlated with subjective severity
  27. likely to reasonably correlate with other severity metrics
  28. possible to label objectively
  29. possible to label nonlinearly (this might be critical for reliability, online usability, and correlation with subjective severity; more later)
  30. enough gradations at most severity levels (contrast both Karnofsky and Bell at severe levels — more later)
  31. able to serve as a reality check
  32. at least slightly grokkable to non-sufferers
  33. capable of averaging fluctuations in severity over time (more later)
  34. rapidly comparable
  35. nonintrusive (in every respect)
  36. not too much to ask
  37. reasonably applicable to most sufferers who self-identify as having the disease (more later)
  38. generally accepted by sufferers (I hope)
  39. and memorable.

You should be able to remember the main part of the scale and its meaning without having to look anything up.

Where these goals conflict with one another, the best balance is sought.

The comments on other scales are not intended to diss them. They are just examples of goals for this scale.


More nerdy blather in future posts.

Multisystem

There is one critical goal that cannot be achieved along with the other goals, and so requires a separate scale.

This scale does not achieve the critical goal of directly measuring the multisystem nature of these diseases.

All existing scales that I am aware of also fail to adequately measure this critical variable. More comprehensive scales are necessary.

Perfect scales are not possible

Perfect scales are not possible. These diseases are enormously multidimensional. The best description of you is you. (But we still need a scale.)

Therefore, like every other scale, we are going to make an imperfect scale. But unlike other scales, we have our own goals. So please bear with it.

The main part

Here is the question I want you to answer:

How many times did you leave the house in the last 365 days?

Notes:

  1. If you are not sure, please say so or provide a range.
  2. Please do not adjust your answer. Answer according to the scale.
  3. Please explain any special circumstances (such as being a hermit or getting infusions every week).

    To meet our goals, we do not define these.

  4. Leaving the house means leaving your house (or apartment, etc.) for any reason. If you were more than 5 meters (about 16 feet) away from the structure for more than 1 minute, then it counts.

    There are no exceptions.

    • EXAMPLE: if you were pushed in your wheelchair 6 meters away from your house twice a day for 2 minutes each time, then you left the house 730 (SEVEN HUNDRED AND THIRTY) times.

    This is to meet our goals, including objectivity, memorability, and reliability.

  5. The numbers are simple:
    • 365 times means once every day on average
    • 52 times means once every week on average
    • 12 times means once every month on average
    • =
    • there are about 260 weekdays in 365 days
    • =
    • 182 times means every other day on average
    • 36 times means 3 times per month on average
    • 6 times means every other month on average
  6. The question states "in the last 365 days". NOT "in the last year". This is to prevent confusion about calendar years.

Very severe level of severity

This scale is completely unsuitable for very severe because it does not distinguish from severe. They are both at or near 0 on the scale. Very severe requires a different measure within the same scale.

Please tell me your suggestions for very severe that also meet the design goals listed above. For example, zero to 5 minutes vertical per 24 hour period. If no objective measure exists that is adequate, then we will either use more conventional descriptions or rely on descriptions supplied with the severity level.

Version

This is version 1.

Version 2 will be identical, but will in addition provide labels and a way to distinguish very severe from severe.

It will also provide a suggested format for Internet polls.

Conclusion

The more a scale is used, the more useful it becomes.

How many times did you leave the house in the last 365 days?

Samuel

Footnotes:

1

SF-36 is routinely used inappropriately, as are scales that are more obviously intended to be denialist.

12 comments :

  1. Hi Patricia,

    Thanks.

    Yes, just one. :)

    I'd really like to ask these also:

    1) how do you describe your severity level (e.g. "mild" or "severe")?

    2) where are you on the Bell scale?

    3) where are you on the Karnofsky scale?

    ReplyDelete
  2. 130, though if checking the post counts (less than a minute but slightly more than 5m) add another 260 for every week day (well, not every but close)

    Should checking the post be a triggering event or not? Just wondering if the time/distance thing should be changed to something shorter so people count that for certain or longer if you don't intend them to? It is a simple thing that people would try to do but many would be unable to do it every day, so if I don't count it (which by these criteria I wouldn't) I'd look more severe than I think I am.


    Damn brilliant concept though!

    Karnofsky = 70 (sometimes 60)

    Bell = Really doesn't work for me as my symptoms at rest are pretty mild but if I do anything vertical they increase rapidly, if I ignore that "at rest" bit of the scale & go off the rest of it 20-30

    I'd consider myself moderate as I can usually self care but there is no way I could realistically work anywhere with the whole horizontal thing.

    ReplyDelete
  3. Hi Ash,

    Thank you. Great questions.

    We don't have access to everything we want to know about the the entire person, any biomarkers, etc., so we have to do the best we can.

    It might be good to revisit this question.

    I prefer people to answer exactly as you did (the strict number and an explanation with a different number) over a bureaucratic, exception-ridden, or subjective scale, for example.

    ===

    I began the scale years ago for a different purpose and forgot why I chose 5 meters instead of 10. 10 might be better because it is more of a Schelling point and it is still within the range some mostly housebound people might find to be possible.

    But there are other options too, such as "getting in a car etc." or "leave the house for more than 10 minutes" or "transgressed the door opening". Time might work better than distance.

    Of course the explanations will always be necessary for some people.

    ===

    It is a tricky question and I'm open to your suggestions.

    By the way, here is the alpaca criterion, which I briefly considered to make the point that there are no exceptions:

    "If an alpaca gently nudges its nose under you and balances you on its back to a supermarket, at which time members of your religious group shop for you, then 6 gymnasts carry you to the emergency room, YOU LEFT THE HOUSE."

    ReplyDelete
  4. I guess it doesn't matter what the leaving the house criteria are or how precisely you define it, someone is always going to find an on the edge situation like what I posted, the issue for comparing person to person is how people handle that.

    Some will silently post the smaller number, some will silently post the larger number & they won't be comparable.

    I can see a scenario where you have two people, one way more disabled than the other but listing the bigger number as they'd rather quote high so as to not be seen as exaggerating things - I mean what do we all constantly get told we are doing?

    Maybe if you put in a "if you are in doubt post two numbers & explain the difference between them" or something like that to make people who are unsure reply as I did?

    Seriously though this "how many times did you leave the house" idea is brilliantly simple & eye opening - anyone posting double or even single digit numbers would shock the hell out of "normals", let alone the zeros :(

    ReplyDelete
  5. Thanks, Prue.

    ===

    Ash, do you think the first 3 notes cover your suggestion?

    # If you are not sure, please say so or provide a range.
    # Please do not adjust your answer. Answer according to the scale.
    # Please explain any special circumstances (such as being a hermit or getting infusions every week).

    ReplyDelete
  6. Oh, apparently I totally missed that, carry on *hides*

    ReplyDelete
  7. Thanks for telling me. I think I will remove the section separator so the notes are in the same section.

    ReplyDelete
  8. Good idea for a scale. I am unsure of the actual number but will put forth two numbers, because of special circumstances.

    The most accurate number would be about 35.

    However, because for much of the past 365 days I have been the only licensed driver in the house, I have HAD to leave more often, perhaps an additional 3 times a month, to drive the car so that my daughter could do errands and shopping, etc. I typically never left the car.

    So if you count those forced upon me by circumstance (and very difficult), a total of 70 to 75.

    I do not know where I am on any other scale.

    ReplyDelete
  9. Good idea for a scale. I am unsure of the actual number but will put forth two numbers, because of special circumstances.

    The most accurate number would be about 35.

    However, because for much of the past 365 days I have been the only licensed driver in the house, I have HAD to leave more often, perhaps an additional 3 times a month, to drive the car so that my daughter could do errands and shopping, etc. I typically never left the car.

    So if you count those forced upon me by circumstance (and very difficult), a total of 70 to 75.

    ReplyDelete
  10. Hi wolfdreams,

    Thank you.

    The result is 70 to 75, with the explanation. It's a harsh scale.

    ReplyDelete

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