Lyme epidemiological data

Discussion in 'Lyme Disease Archives' started by lpn9999, Sep 30, 2008.

  1. lpn9999

    lpn9999 New Member

    This post is in response to someone on the fibromyalgia board who was looking for data on the geographic characteristics of Lyme - particularly in regard to neighborhoods. I don't have the background required in statistics to answer the specific questions - but there are good sources for data out there. I certainly don't know this stuff off the top of my head.

    The CDC keeps state by state data. To understand this, it is very important to understand what they are measuring, and how that relates to clinical diagnosis. (Outside what I have time to go into today.)
    http://www.cdc.gov/ncidod/dvbid/lyme/ld_rptdLymeCasesbyState.htm

    Pubmed is a repository for research. http://www.ncbi.nlm.nih.gov/sites/entrez

    A search on "lyme neighborhood" brought back 19 hits, some of which look interesting.

    If anyone is aware of better data, please add it here.

    Thanks,

    Lisa
  2. lpn9999

    lpn9999 New Member

    Kathy, you're absolutely right. It seems like even the CDC was clear at first that they were looking to gather statistical information - so they emphasized a specific, narrow definition so that they could have consistent statistics. I'm still astounded that criteria designed for statistical purposes ended up being used for diagnosis.

    How to track a disease that has no "gold standard" test and has symptoms that mimic many others is a really hard problem. In statistics, you can handwave away a lot of the complexity and still have useful information - as long as you remember exactly what you counted. In medicine, when you handwave away complex patients you handwave away treatment for real people. :-(

    Lisa
    (who is mainly trying to move the discussion...)
  3. lpn9999

    lpn9999 New Member

    I just read it - wow. She did a great job with making the history and biology coherent. I think I cried through half of it, too. Not the biology parts of course, but every story about a family was so much like what my daughter is going through. Fortunately, no one else in the immediate family is diagnosed with it now.

    My daughter is still having a rough time, but after about 5 weeks of treatment (we finally got in to see a Lyme doc in August) she's having more "good" hours on more days. She gets so disappointed. She sees two steps forward, one step back (or one step forward, one step back) as nowhere near fast enough. For now, I'm just relieved not to watch step back, step back, step back and wonder how long she can take it.

    How is your daughter?

    Lisa
  4. lpn9999

    lpn9999 New Member

    I picked up a copy of Under Our Skin. If anything, it is more emotional in content than Cure Unknown. It's really, really worth it though.

    It ends on a much more optimistic note than Cure Unknown. It would be *much* more depressing if you turn it off 2/3 of the way through. There's a few parts that are very difficult to watch.

    My daughter is back in school part time after missing most of the last year and a half. There's some bumps, but in general we're working them out with the teachers. We've been told that three months is when you have a pretty good idea how it's going - so kind of holding my breath until then.
  5. Rafiki

    Rafiki New Member

    CDC's numbers 10/01/08 01:42 PM

    Hi Lisa,

    I have seen that chart a few times.

    When you take into account that...

    1) CDC has said cases of LD are tenfold more than what is reported and
    2) Presumably only those who are CDC+ are reported and
    3) Not all MDs report their cases to the CDC,

    The actual numbers are substantially higher. Take CT's 2007 figure of 3058 per 100,000 for example. Since that 3058 is underreported by tenfold, logically the number would be 30,580 per 100,000, or a whopping 30.58%

    Imagine how much higher that figure would be if those Igenex/Clongen/MDL positive and those clinically diagnosed were included in that figure.

    But, not to worry. At least there's no epidemic.
    ______________________________________________________________


    Hi Kathy,
    I know it matters to you that the information you disseminate be accurate.

    It's not 3058 per 100,000; it's 3058 for the entire state. Ergo, all further manipulation of these figures will only lead to erroneous conclusions.

    :~)
    Rafiki
  6. Rafiki

    Rafiki New Member

    I really do understand how important accuracy is to you but I went to the link you provided and they are numbers for the state, not per 100,000.

    I really wouldn't post this had I not been sure.

    Of course, I could have made sure and still been wrong. It has happened! I will check again.

    :~)
    Rafiki
  7. Rafiki

    Rafiki New Member

    3058 for the entire state for 2007
    Incidence (* cases per 100,000 population) 87.3

    Under Lyme statistics at the CDC, choose by state and there is a table.

    Peace out,
    Rafiki
  8. Rafiki

    Rafiki New Member

    http://www.cdc.gov/ncidod/dvbid/lyme/ld_rptdLymeCasesbyState.htm

    Reported Lyme disease cases by state, 1993-2007

    Column headings
    State 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 Incidence 2007*

    Items in column
    Connecticut 1350 2030 1548 3104 2297 3434 3215 3773 3597 4631 1403 1348 1810 1788 3058 87.3

    This at the bottom of the chart.
    * cases per 100,000 population

    The asterisk next to Incidence 2007 indicates that this column, as per the explanation at bottom of chart, is the incidence column - numbers per 100,000. Under Incidence it says 87.3

    There are no asterisks next to any of the other columns because they are the total numbers. The only year for which incidence is given is 2007, total numbers only are given for other years.

    I understand that these numbers are highly debatable but I know you want to quote statistics accurately even if the source may not rock solid.

    I hope this helps.

    :~)
    Rafiki

    ETA I copied the columns, numbers and * info. directly from your post.

    [This Message was Edited on 10/01/2008]
  9. Rafiki

    Rafiki New Member

    I've totally been there with the brain fog and I've had densebrain, too, I'm sure! But, was having a rare moment of clarity with this.

    Re your question. Well, I'm not any more trusting of CDC than you are. I didn't see the statement about it being 10 fold underreported but, if they are right, I think that 873 per 100,000 is still a pretty alarming number. However, like you, I wouldn't take it to the bank because of all the confounding factors.

    I really don't know. I don't have an opinion re Lyme disease or Chronic Lyme disease. I don't know. I sincerely hope it gets sorted out because, no matter the number nor the outcome of the current quarrel, it is a pressing issue.

    I just don't know.
    :~)
    Rafiki

    [This Message was Edited on 10/01/2008]
  10. Rafiki

    Rafiki New Member

    This is our longest conversation! :~)

    I did take stat.s long ago and, as far as the reading of the chart goes, they did mean an incidence of 87.3 per 100,000.

    But, as you say, how reliable are these numbers anyway? The CDC bungled ME pretty badly renaming it CFS and lumping every sick person who's ever had to lie down in one patient cohort!

    I think there is a great deal of bad feeling left over from a time when people behaved very badly. I'm actually sorry that the other thread on ME/FM was yanked because it contained a post by Munch where someone (can't remember who :) said that he, every so often, very gently, with great care... suggested that people who were chronically ill get tested for Lyme.

    I think we only need all that care and caution for a little while until the dialogue takes on a more constructive air. There were people who were insulted pretty badly. The careless accusations flew thick and fast. It was not our finest hour.

    I see no reason why Lyme cannot be mentioned, when appropriate, as a possible avenue of investigation for those with ME or Fm or CFS. I see it as no different from Mycoplasma or HHV6. People do not get at all shirty about those things.

    Maybe we all need to back off a little and then proceed with respect, care and open minds on both sides. So long as we are trying to convince each other of our own point of view this will continue.

    As for me: I just don't know.

    Peace out,
    Rafiki

    PS it's sleepy here, I sure hope I just made sense!

  11. lpn9999

    lpn9999 New Member

    Here's how I read the data in the CDC report after digging around.

    1. The annual figure columns are raw numbers - i.e. total for state of CT
    2. The final column is cases per 100,000 - which is why it doesn't agree with the other columns.
    3. I did some quick research to validate. The Connecticutt Department of Health lists the 2006 population of CT as 3,510,787. (http://www.ct.gov/ecd/cwp/view.asp?a=1106&q=250666) If you muliptly 87 by 35 (roughly the number of times 100,000 goes into 3,510,787) you get 3,045 (which is roughly the raw number for the year.)

    I think that the grid is pretty unclear on this - it could have been labeled more clearly. I think we see why the CDC is so comfortable saying that 10x higher is possible. :p

    If anyone wants to dig into this (not me), it looks like Mass Dept of Health (http://www.mass.gov/dph) collects town by town numbers. Other states probably do the same. Newspaper articles cite their population figures (see examples below). I don't know if the state uses the same criteria as the CDC.

    http://www.boston.com/news/local/massachusetts/articles/2008/09/04/lyme_disease_cases_continue_to_rise_on_nantucket/

    http://www.mvtimes.com/news/2007/06/14/lyme_cases.php
  12. Rafiki

    Rafiki New Member

    Yeah, that's how you read the chart. It's pretty standard.

    As to all else.

    I know nothing.

    Rafiki
  13. gapsych

    gapsych New Member


    I have an extensive background in statistics. However, right now I am too foggy to look at the numbers as I am sure they would be jumping all over the page.

    Right now, if pressed, I could maybe come up with mean, medium and mode, LOL!!!

    I also dated a statistics professor for five years, but do not think that counts!!!

    I am curious to look at them, though as I love numbers.

    Take care.

    GA
  14. victoria

    victoria New Member

    altho I don't think there's any disagreement as to that. I do personally know doctors and patients in Georgia who treated pts or were treated for lyme (respectively) - based solely on a clinical diagnosis...

    ie, a person was in a park or went deer hunting, etc., may or may not remember seeing a tick, may or may not have seen a rash, but usually remembers coming down with the 'flu' shortly after;

    then their health starts deteriorating within a couple months, ie, muscle &/or joint pain, mental confusion, vision blurring... not necessarily all or many symptoms, even just one.

    So cut to the chase for the bottom line for doctors AND patients:
    It's much less expensive and less of a hassle to give abx, especially when a doctor has had a few diagnosed. And at least where I lived for the past 30 years, most people didn't have much, if any, health insurance.



  15. lpn9999

    lpn9999 New Member

    I believe that the Guidelines found in the National Guidelines Clearinghouse (http://guidelines.gov) are an authoritative source of information, representing mainstream consensus for how doctors should treat patients.

    The current guidelines for treatment of Lyme disease (http://guidelines.gov/summary/summary.aspx?doc_id=4836&nbr=003481&string=lyme) give a concise description of the difference between diagnosing a patient for the purposes of treatment, and the data that CDC collects. On reading documents from NGC and CDC, my take is that although you can parse the "up tos" several ways, there is no mainstream dispute that more people should be treated for Lyme than should be reported to CDC. Any dispute is over what the factor of underreporting is. Quotes from Guidelines.gov and CDC follow. Some have been slightly edited for length.

    guidelines.gov
    "Treatment decisions should not be based routinely or exclusively on laboratory findings. The two-tier diagnostic criteria, requiring both a positive enzyme-linked immunosorbent assay (ELISA) and western blot, lacks sensitivity and leaves a significant number of individuals with Lyme disease undiagnosed and untreated. These diagnostic criteria were intended to improve the specificity of tests to aid in identifying well-defined Lyme disease cases for research studies. Though arbitrarily chosen, these criteria have been used as rigid diagnostic benchmarks that have prevented individuals with Lyme disease from obtaining treatment. Diagnosis of Lyme disease by two-tier confirmation fails to detect up to 90% of cases and does not distinguish between acute, chronic, or resolved infection.

    The Centers for Disease Control and Prevention (CDC) considers a western blot positive if at least 5 of 10 immunoglobulin G (IgG) bands or 2 of 3 immunoglobulin M (IgM) bands are positive. However, other definitions for western blot confirmation have been proposed to improve the test sensitivity. In fact, several studies showed that sensitivity and specificity for both the IgM and IgG western blot range from 92 to 96% when only two specific bands are positive. "

    "Since there is currently no definitive test for Lyme disease, laboratory results should not be used to exclude an individual from treatment.
    Lyme disease is a clinical diagnosis and tests should be used to support rather than supersede the physician’s judgment."

    "Early Lyme disease classically presents with a single erythema migrans (EM or "bull’s-eye") rash. The EM rash may be absent in over 50% of Lyme disease cases, however."
    "Physicians should be aware that fewer than 50% of all Lyme disease patients recall a tick bite. "

    For reference, here is the CDC surveillance case definition: http://www.cdc.gov/ncidod/dvbid/lyme/ld_statistics.htm and http://www.cdc.gov/ncphi/disss/nndss/casedef/lyme_disease_2008.htm
    "Reporting of all nationally notifiable diseases, including Lyme disease, is based on standard surveillance case definitions developed by the Council of State and Territorial Epidemiologists (CSTE) and CDC. The usefulness of public health surveillance data depends on its uniformity, simplicity, and timeliness. Surveillance case definitions establish uniform criteria for disease reporting and should not be used as the sole criteria for establishing clinical diagnoses, determining the standard of care necessary for a particular patient, setting guidelines for quality assurance, or providing standards for reimbursement."

    And here's the definition (summary) for Lyme
    "Confirmed: a) a case of EM with a known exposure, or b) a case of EM with laboratory evidence of infection and without a known exposure or c) a case with at least one late manifestation that has laboratory evidence of infection."
  16. Rafiki

    Rafiki New Member

    Are you still having trouble understanding the chart?

    Can I be of any help?

    Peace to you,
    Rafiki
  17. Rafiki

    Rafiki New Member

    Yes, that's exactly right!

    :~)
    Rafiki
  18. lpn9999

    lpn9999 New Member

    We've got (actually need to sign next week) a 504. I would have preferred an IEP, but so far this year they've agreed to what we need and the teachers have been very good. It helps that we've been seeing improvement and they really want her fully back in the mainstream so they're willing to put effort into getting her there. We'll have more of a challenge if there is a setback and we need home tutoring or alternative placement.

    On Lymenet: I read it, but not as frequently as here. Apparently, I've never even created an ID. Go figure, I thought I'd posted but it was probably here instead. Maybe I'll get to it today - do you have the same name over there?

    Lisa
  19. lpn9999

    lpn9999 New Member

    I sent you a short PM on the "other site" so you'd have my id. Too tired for more posts tonight.

    Lisa
  20. Rafiki

    Rafiki New Member

    You're right!

    I was so focused on the difficulty people were having linking the asterisk with the column to which it referred that I lost track of the numbers right along with Grammy27.

    Just in case anyone remains in the state of confusion I inhabited... if 30,580 were 10% of the population of CT, the population would be 305,580 not 3,510,787!

    I feel so silly!

    :~)
    Rafiki






    [This Message was Edited on 10/06/2008]