The benefits/risks of colonoscopy (split from "confident of chiropracty")

[jhunter1163]

The colonoscopy discussion from here (http://forums.randi.org/showthread.php?t=137298)morphed into it's own topic, so I've split it to a new thread.So you accept faith healing and homeopathy as effective treatment then?

Pain relief is highly subject to the placebo effect.

I said nothing about faith healing or homeopathy, neither of which I support. Please don't put words in my mouth.

You could make the same argument about physiotherapy, but I don't see anyone doing that. The reason chiropractic is so reviled is that it has a "philosophy", and its scientific basis is dubious (the "subluxation").

And before people start going on about the risks of chiropractic (which I acknowledge as real, by the way) let me ask this; the risk of death from colonoscopy is as high as 1 in 3,000. Source:

http://coloncancer.about.com/od/screening/a/ColonoscopyRisk.htm

Why is this risk acceptable?

[ponderingturtle]

I said nothing about faith healing or homeopathy, neither of which I support. Please don't put words in my mouth.

But people with back pain get cured by those treatments. You are basicly saying that if people made the same arguement using the same citations used here, you would call BS on them if it was for homeopathy or faith healing.


Those do truely make people feel better.


You could make the same argument about physiotherapy, but I don't see anyone doing that. The reason chiropractic is so reviled is that it has a "philosophy", and its scientific basis is dubious (the "subluxation").

There are many reasons why chiropractic is reviled. It makes claims beyond anything that is supported by evidence, and it is no more helpful and more risky than other treatments.

And before people start going on about the risks of chiropractic (which I acknowledge as real, by the way) let me ask this; the risk of death from colonoscopy is as high as 1 in 3,000. Source:

http://coloncancer.about.com/od/screening/a/ColonoscopyRisk.htm

Why is this risk acceptable?

What is the risk of not getting colonoscopies? It is not about absolute risk, sure chiropractic is safer that heart transplants, but that means nothing. Is it either safer or more effective than other ways of treating back pain? The answer is that it is more risky and no better.

So you increase the risk to the patient for no benefit.

[Professor Yaffle]

What is the risk of not getting colonoscopies?


A bit off topic, but I had a discussion elsewhere recently which seemed to suggest that the risks of colonoscopies (heavy bleeding, bowel perforation and in very rare cases - death) on an unscreened population was numerically higher than the risks of not getting a colonoscopy. I'll see if I can find it.

Am I right in thinking that colonoscopies are done routinely (ie on a unscreened population) in the US for over 50s?

ETA: http://www.badscience.net/forum/viewtopic.php?f=6&t=7978

[jhunter1163]

Colonoscopy is recommended routinely in the US for people over the age of 50.

What is the benefit of a negative colonoscopy? Nothing, except possibly peace of mind. So in colonoscopy we have a procedure that is of no benefit in almost every case (excepting those few cases where cancer/polyps are detected) and has a risk of death considerably higher than the risk of chiropractic. And yet, no outrage, no signs on buses warning of the evils of colonoscopy.

I am not attempting to devalue gastroenterology, just to point out a bit of hypocrisy on the part of the anti-chiro crowd. And, again, I'm not keen on chiropractic outside of its limited niche.

[Professor Yaffle]

Colonoscopy is recommended routinely in the US for people over the age of 50.

What is the benefit of a negative colonoscopy? Nothing, except possibly peace of mind. So in colonoscopy we have a procedure that is of no benefit in almost every case (excepting those few cases where cancer/polyps are detected) and has a risk of death considerably higher than the risk of chiropractic. And yet, no outrage, no signs on buses warning of the evils of colonoscopy.

I am not attempting to devalue gastroenterology, just to point out a bit of hypocrisy on the part of the anti-chiro crowd. And, again, I'm not keen on chiropractic outside of its limited niche.

The links in the thread I linked to suggest about 1 in 600 will have cancer diagnosed following colonoscopy (over 50s without prior screening with FOBT), but also that there is a 1 in 150 chance of heavy bleeding which will need further medical investigation/advice, a 1 in 1500 chance of perforation and about 1 in 10,000 chance of death.

[fls]

And before people start going on about the risks of chiropractic (which I acknowledge as real, by the way) let me ask this; the risk of death from colonoscopy is as high as 1 in 3,000. Source:

http://coloncancer.about.com/od/screening/a/ColonoscopyRisk.htm

Why is this risk acceptable?

Because the risk of death from not performing colonoscopy (i.e. failing to prevent and treat cancer) is higher.

Linda

[Professor Yaffle]

Because the risk of death from not performing colonoscopy (i.e. failing to prevent and treat cancer) is higher.

Linda

Is that still true if you are comparing total deaths from cancer and colonoscopies performed on all over 50s compared with screening with FOBT and only doing colonoscopies on those with a positive result? Because we are questioning the wisdom of doing routine colonoscopies in the over 50s, not the wisdom of doing colonoscopies at all. Anybody want to do the sums? I think I have all the relevant numbers, but my brain won't do the sums correctly at the moment I fear.

[Rodney]

Because the risk of death from not performing colonoscopy (i.e. failing to prevent and treat cancer) is higher.Linda
Has anyone evaluated the risk/benefit ratio of regular colonoscopies vs. virtual (i.e., CAT scan) colonoscopies?

[paximperium]

Is that still true if you are comparing total deaths from cancer and colonoscopies performed on all over 50s compared with screening with FOBT and only doing colonoscopies on those with a positive result? Because we are questioning the wisdom of doing routine colonoscopies in the over 50s, not the wisdom of doing colonoscopies at all. Anybody want to do the sums? I think I have all the relevant numbers, but my brain won't do the sums correctly at the moment I fear.

She presented a detailed cost-benefit analysis of introducing a screening colonoscopy program for the 8,300 members over age 50 enrolled in the Duke Managed Care Plan, a health plan that has established the true costs of various medical procedures. Her projections were based on a decision-analysis model that assumed a 0.5% prevalence of colorectal cancer at the initial screening colonoscopy and a 1.5% incidence of cancer over the next 10 years.


The projected costs and savings of screening colonoscopy during a 10-year period were compared with those of a screening strategy based on annual fecal occult blood testing, which is the current screening practice in Duke's primary care clinics.


Screening colonoscopy would lead to a fourfold increase in total colonoscopies, compared with the number generated by fecal occult blood screening. There also would be a threefold rise in colonoscopy complications. Together, this would cost the managed care plan an additional $5.6 million over 10 years. But the number of colorectal cancer surgeries would fall by 57%, leading to a net savings of $1 million. Colon cancer deaths would fall by 53%, with a proportionate reduction in the cost of end-of-life care.
http://findarticles.com/p/articles/mi_m0BJI/is_3_31/ai_71632713

[paximperium]

Has anyone evaluated the risk/benefit ratio of regular colonoscopies vs. virtual (i.e., CAT scan) colonoscopies?
Virtual Colonoscopy is still not recommended due to its poorer sensitivity compared to Endoscopic Colonoscopy but it becoming better. It will undoubtedly be used as a major screening tool down the line.

However remember, VC cannot remove polyps or do biopsies. If the VC picks up something, you'll still need a EC to remove the polyp or perform the biopsy.

[Professor Yaffle]

http://findarticles.com/p/articles/mi_m0BJI/is_3_31/ai_71632713


Thanks, interesting. Would be better to see the analysis itself, do you know if it has been published anywhere? Or anything similar been published? I am particularly interested in the workings for the 53% decrease in colon cancer deaths. Last i checked, the FOTB test had a 92% sensitivity and take up of colonoscopy following positive test was about 80% (but this would include people who then went private for their colonoscopies, so would show up as not taking it up on NHS figures).

ETA based on those figures, about 75% of cases would be picked up using FOTB followed by colonoscopy for positive tests. And thats a worst case scenario, assuming that the 20% that don't have a colonoscopy with the NHS following a positive test do not follow it up at all.

[fls]

Is that still true if you are comparing total deaths from cancer and colonoscopies performed on all over 50s compared with screening with FOBT and only doing colonoscopies on those with a positive result? Because we are questioning the wisdom of doing routine colonoscopies in the over 50s, not the wisdom of doing colonoscopies at all. Anybody want to do the sums? I think I have all the relevant numbers, but my brain won't do the sums correctly at the moment I fear.

I was referring to the use of routine colonscopies for screening. FOBT discovers less than a third of the cancers that colonscopy discovers.

Linda

[fls]

Has anyone evaluated the risk/benefit ratio of regular colonoscopies vs. virtual (i.e., CAT scan) colonoscopies?

Well, that's why the technology is being developed and its use encouraged - it is less risky and is almost as useful.

Linda

[Professor Yaffle]

I was referring to the use of routine colonscopies for screening. FOBT discovers less than a third of the cancers that colonscopy discovers.

Linda

Really? - my reading suggested that though the sensitivity of the test is low, it rises to about 92% sensitivity when 3 tests are done (as is standard). Have you got some links for me?

ETA - ah I think I see where I have erred (blame wikipedia), I thought the testing of 3 samples meant that repeated tests were done - increasing the sensitivity. But the increased sensitivity is when repeated tests are done over time. They are done every 2 years I think on the NHS - so does that increase the proportion of cancers detected?

(and do you think I should ask for this to be split off to a new thread?)

[fls]

Really? - my reading suggested that though the sensitivity of the test is low, it rises to about 92% sensitivity when 3 tests are done (as is standard). Have you got some links for me?

ETA - ah I think I see where I have erred (blame wikipedia), I thought the testing of 3 samples meant that repeated tests were done - increasing the sensitivity. But the increased sensitivity is when repeated tests are done over time. They are done every 2 years I think on the NHS - so does that increase the proportion of cancers detected?

Yes.

(and do you think I should ask for this to be split off to a new thread?)

Well, this issue has been heavily debated for years and there's still no good answer. So, we should probably give up now. :)

Linda

[Professor Yaffle]

I'll shut up after this post then.

Colonoscopy is a very good test for diagnosing cancer. But there's not enough research to say whether it is a good screening test. And we don't know whether the risk of harm from having this test outweighs the benefits.
http://www.guardian.co.uk/lifeandstyle/besttreatments/bowel-cancer-screening-treatments

[Prometheus]

I'll shut up after this post then.


http://www.guardian.co.uk/lifeandstyle/besttreatments/bowel-cancer-screening-treatments

Apologies for coming in late, but I just want to add that the question of risk/benefit for routine colonoscopy can also be affected by how diligently maintenance is performed on the equipment being used. My brother used to perform contract maintenance on endoscopes for a lot of the hospitals in my area, and he tells me that many hospitals would try to save money by choosing low-ball service contracts, and at least two thirds of the scopes from such hospitals came to him not cleaned or sanitized and in a state of advanced disrepair, well beyond where they'd be safe to use on a patient. When he went in for a colonoscopy himself, he insisted on disassembling and inspecting the unit that was to be used on him, beforehand.

[Rodney]

Well, that's why the technology is being developed and its use encouraged - it is less risky and is almost as useful.

Linda
Doesn't your answer imply that the risk/benefit ratio for virtual colonoscopies may well be more favorable for most people than regular colonoscopies? For example, if -- based on known risk factors -- the odds are 90% that a regular colonoscopy will not find any polyps in a given individual, why should that individual take the risk of having a regular colonoscopy?

To answer my own question, I think the answer is basically cost, because virtual colonoscopies are almost never covered by medical insurance, whereas regular ones are. There is also, of course, the hassle of having to undergo a regular colonoscopy if a virtual one reveals a polyp, but I think far more people would have virtual ones if they were covered by insurance. So, it appears that the current insurance set-up is encouraging riskier behavior in this respect. In fact, if virtual colonoscopies were covered by insurance, it is likely that many people who are too scared to have regular colonoscopies would have virtual ones.

[fls]

I guess the colonoscopy thread should be split off.

I'm going to hold my responses until then.

Linda

[fls]

I'll shut up after this post then.

Colonoscopy is a very good test for diagnosing cancer. But there's not enough research to say whether it is a good screening test. And we don't know whether the risk of harm from having this test outweighs the benefits.
http://www.guardian.co.uk/lifeandstyle/besttreatments/bowel-cancer-screening-treatments

The questions you ask for whether a diagnostic test makes a good screening test are:

1. Does early diagnosis really led to improved survival, or quality of life, or both?

2. Are the early diagnosed patients willing partners in the treatment strategy?

3. Is the time and energy it will take us to confirm the diagnosis and provide (lifelong) care well spent?

4. Do the frequency and severity of the target disorder warrant this degree of effort and expenditure?

Colonoscopy is clearly the best diagnostic test to use, since it is the most sensitive and specific and it serves to provide treatment at the same time. And we can demonstrate improved survival (through case-control studies and sub-group analysis of RCT's). But implementing it for general screening will mean that a potentially larger risk (as it is performed by less skilled operators in order to fulfill need) is placed upon a population with decreasing benefit. As it is implemented, the trend will be towards (relatively) increasing incidence of early disease (i.e. polyps rather than cancer) and decreasing incidence of later, but still treatable, disease. The 'life saved' per case found will gradually decrease. FOBT, on the other hand, tends to have a lower limit of detection - i.e. it mostly detects cancer and not polyps - so the relative incidence will show less change.

So really, it needs a head-to-head comparison of the two or three (if we include virtual colonoscopy) to confirm that the effort and expenditure are worth the additional benefits. While the evidence would be adequate to recommend it for most other applications, when it comes to screening, because we are now talking about interfering with healthy people, we need confirmation of what we think is best.

Linda

[fls]

Doesn't your answer imply that the risk/benefit ratio for virtual colonoscopies may well be more favorable for most people than regular colonoscopies? For example, if -- based on known risk factors -- the odds are 90% that a regular colonoscopy will not find any polyps in a given individual, why should that individual take the risk of having a regular colonoscopy?

To answer my own question, I think the answer is basically cost, because virtual colonoscopies are almost never covered by medical insurance, whereas regular ones are. There is also, of course, the hassle of having to undergo a regular colonoscopy if a virtual one reveals a polyp, but I think far more people would have virtual ones if they were covered by insurance. So, it appears that the current insurance set-up is encouraging riskier behavior in this respect. In fact, if virtual colonoscopies were covered by insurance, it is likely that many people who are too scared to have regular colonoscopies would have virtual ones.

The answer is that there isn't yet enough evidence to recommend virtual colonoscopies. The studies have compared detection rates, but it hasn't been studied as a screening tool, so we don't know whether it reduces mortality. Also, CT scan detects other abdominal abnormalities, so you need to take into account the additional investigation (harm and benefit) that comes about from incidentally discovering a nodule in the kidney, for example.

Linda

[Professor Yaffle]

What about flexible sigmoidoscopy - also mentioned in the guardian/bmj article I linked to? I hadn't heard of that before but looks much less likely to cause damage than colonoscopy.

[Rodney]

The answer is that there isn't yet enough evidence to recommend virtual colonoscopies. The studies have compared detection rates, but it hasn't been studied as a screening tool, so we don't know whether it reduces mortality.
How can it not help reduce mortality? According to http://www.webmd.com/colorectal-cancer/news/20080917/virtual-colonoscopy-real-accuracy --

"Virtual colonoscopy -- colon cancer screening using CT scans -- finds 90% of large, precancerous polyps.

"The finding comes from 15 academic and community medical centers that performed both virtual colonoscopy (CT colonography) and traditional colonoscopy on 2,600 patients aged 50 and older.

"The study 'validates' new guidelines endorsing virtual colonoscopy as a colon cancer screening option, says study leader C. Daniel Johnson, MD, professor of radiology at the Mayo Clinic in Scottsdale, Ariz."

Also, CT scan detects other abdominal abnormalities, so you need to take into account the additional investigation (harm and benefit) that comes about from incidentally discovering a nodule in the kidney, for example.
I would think if you have a competent and ethical doctor, the benefit of finding another abdominal abnormality would have to outweigh any harm. If s/he (or someone else) can treat that abnormality, treatment could be life-saving. If not, s/he can say: "I have good news and bad news. The good news is that no polyps were found. The bad news is that you're going to die within six months of an unrelated problem." ;)

[fls]

What about flexible sigmoidoscopy - also mentioned in the guardian/bmj article I linked to? I hadn't heard of that before but looks much less likely to cause damage than colonoscopy.

Yeah, in particular flex sig plus FOBT.

It's a limited exam - it looks at about the last 20% of the colon and it involves less traction (so less risk of perforation).

Linda

[fls]

How can it not help reduce mortality? According to http://www.webmd.com/colorectal-cancer/news/20080917/virtual-colonoscopy-real-accuracy --

"Virtual colonoscopy -- colon cancer screening using CT scans -- finds 90% of large, precancerous polyps.

"The finding comes from 15 academic and community medical centers that performed both virtual colonoscopy (CT colonography) and traditional colonoscopy on 2,600 patients aged 50 and older.

"The study 'validates' new guidelines endorsing virtual colonoscopy as a colon cancer screening option, says study leader C. Daniel Johnson, MD, professor of radiology at the Mayo Clinic in Scottsdale, Ariz."

Like you say, it should reduce mortality. It's just that when we are talking about screening, 'should' isn't really good enough. We need to know whether or not it does. Sometimes stuff that 'should' do something, doesn't after all. Plus we are also interested in comparing several strategies in order to find the one that makes best use of effort and expenditure.

I would think if you have a competent and ethical doctor, the benefit of finding another abdominal abnormality would have to outweigh any harm. If s/he (or someone else) can treat that abnormality, treatment could be life-saving. If not, s/he can say: "I have good news and bad news. The good news is that no polyps were found. The bad news is that you're going to die within six months of an unrelated problem." ;)

The problem is that investigating incidental lesions can also lead to harm and death. So you may be causing a death in someone who had an abnormality that was never going to affect them or didn't even have an abnormality in the first place. This is not a trivial concern.

Linda

[paximperium]

I would think if you have a competent and ethical doctor, the benefit of finding another abdominal abnormality would have to outweigh any harm. If s/he (or someone else) can treat that abnormality, treatment could be life-saving. If not, s/he can say: "I have good news and bad news. The good news is that no polyps were found. The bad news is that you're going to die within six months of an unrelated problem." ;)
Let me see. We see a weird spot in your kidney that does absolutely nothing but it has made you worried. So you perform a CT of the kidneys, then a biopsy of the kidney...oops, the kidney site is now bleeding. You end up in the hospital. The biopsy comes back as a normal cyst. You end up with a $20000 bill for nothing.

Add this to the thousands of similar incidental findings and the risk of bad things increase. There is a risk with everything even doing workups on benign things.

[Rodney]

Let me see. We see a weird spot in your kidney that does absolutely nothing but it has made you worried. So you perform a CT of the kidneys, then a biopsy of the kidney...oops, the kidney site is now bleeding. You end up in the hospital. The biopsy comes back as a normal cyst. You end up with a $20000 bill for nothing.

Add this to the thousands of similar incidental findings and the risk of bad things increase. There is a risk with everything even doing workups on benign things.
This is why I included the word "ethical." It seems to me that an ethical doctor would say to the patient something like: "Your virtual colonoscopy was normal, but we found a weird spot in your kidney. Since you have no symptoms, there is a good chance that there is nothing to be concerned about. However, we could do a CT and/or biopsy of the kidneys, both of which involve obvious inconvenience, as well as some risk and expense, specifically . . . Why don't you think about what you want to do and get back to me?"

[Rodney]

Like you say, it should reduce mortality. It's just that when we are talking about screening, 'should' isn't really good enough. We need to know whether or not it does. Sometimes stuff that 'should' do something, doesn't after all. Plus we are also interested in comparing several strategies in order to find the one that makes best use of effort and expenditure.
So what do you currently recommend to friends and acquaintances in this regard (assuming that they have no symptoms)?

1) Get a regular colonoscopy at age . . .(50, 55, 60?), and every (5, 10, 15?) years later.

2) Get a virtual colonoscopy at age . . .(50, 55, 60?) and every (5, 10, 15?) years later.

3) Get a flex sig plus FOBT at age . . .(50, 55, 60?) and every (5, 10, 15?) years later.

4) Some combination of (1)-(3); e.g., do (1) at age 50, (2) at age 60, (3) at age 70, etc.

5) Do nothing.

[fls]

This is why I included the word "ethical." It seems to me that an ethical doctor would say to the patient something like: "Your virtual colonoscopy was normal, but we found a weird spot in your kidney. Since you have no symptoms, there is a good chance that there is nothing to be concerned about. However, we could do a CT and/or biopsy of the kidneys, both of which involve obvious inconvenience, as well as some risk and expense, specifically . . . Why don't you think about what you want to do and get back to me?"

It's not really possible to give a patient enough information for them to make the decision (or fair to them to make them responsible for the outcome). Because, for one thing, it's a decision that even we struggle with, and for another, it helps to have some experience making these decisions. That said, no matter how hard you try to figure out when it is safe to go and when it is safe to stop in advance, you will sometimes be wrong.

Linda

[fls]

So what do you currently recommend to friends and acquaintances in this regard (assuming that they have no symptoms)?

1) Get a regular colonoscopy at age . . .(50, 55, 60?), and every (5, 10, 15?) years later.

2) Get a virtual colonoscopy at age . . .(50, 55, 60?) and every (5, 10, 15?) years later.

3) Get a flex sig plus FOBT at age . . .(50, 55, 60?) and every (5, 10, 15?) years later.

4) Some combination of (1)-(3); e.g., do (1) at age 50, (2) at age 60, (3) at age 70, etc.

5) Do nothing.

Colonoscopy every 10 years. ETA: Starting at age 50.

Linda

[Rodney]

It's not really possible to give a patient enough information for them to make the decision (or fair to them to make them responsible for the outcome). Because, for one thing, it's a decision that even we struggle with, and for another, it helps to have some experience making these decisions. That said, no matter how hard you try to figure out when it is safe to go and when it is safe to stop in advance, you will sometimes be wrong.

Linda
I prefer it when the doctor presents me with all relevant facts and then gives me his/her best judgement, as opposed to only giving me his/her best judgement.

[Rodney]

Colonoscopy every 10 years. ETA: Starting at age 50.

Linda
Okay, thanks. Is your preference for the regular colonoscopy over the virtual one mainly based on the fact that the virtual misses small growths?

[fls]

I prefer it when the doctor presents me with all relevant facts and then gives me his/her best judgement, as opposed to only giving me his/her best judgement.

Of course. I'm just saying that it doesn't solve the problem of unnecessary harm.

Linda

[fls]

Okay, thanks. Is your preference for the regular colonoscopy over the virtual one mainly based on the fact that the virtual misses small growths?

Yes, mainly.

Linda

[Rodney]

Yes, mainly.

Linda
But is there evidence that removal of small growths prolongs life?

[fls]

But is there evidence that removal of small growths prolongs life?

Yes, there is evidence that removal of all polyps makes a much greater difference on mortality cancer incidence than waiting until they are larger before removal. This evidence comes from combining information from several different studies (mostly the National Polyp Study). I think there are one or two studies in progress that are designed to answer the question directly.

Linda

[Professor Yaffle]

Referring back to the percentage of cancers that will be picked up by FOBT - this study of regional screening in England puts it at about 60% which seems a lot higher than quoted earlier in the thread.

http://www.nature.com/bjc/journal/v97/n12/full/6604089a.html
Interval cancers and sensitivity
There were 98 interval cancers occurring within 2 years of a negative screen in the first round. The sensitivity of FOBt in the first round was estimated as 57.7% (95% CI: 48.4–65.6) or 64.4% (95% CI: 56.6–71.1) according to whether England or West Midlands rates were used to calculate expected incidence in the absence of screening.
This estimate of sensitivity is similar to that of 62.7% observed in the Nottingham trial (Moss et al, 1999 (http://www.nature.com/bjc/journal/v97/n12/full/6604089a.html#bib6)). However, in the Pilot sensitivity was higher in men than in women and this difference is in the opposite direction to that observed in the Nottingham trial.

[fls]

Referring back to the percentage of cancers that will be picked up by FOBT - this study of regional screening in England puts it at about 60% which seems a lot higher than quoted earlier in the thread.

http://www.nature.com/bjc/journal/v97/n12/full/6604089a.html

Yeah, that's a problem with using guesses instead of direct measurements - you can get quite disparate results.

Linda

[Rodney]

Yes, there is evidence that removal of all polyps makes a much greater difference on mortality cancer incidence than waiting until they are larger before removal.
So waiting increases cancer incidence, but does not necessarily increase mortality?

This evidence comes from combining information from several different studies (mostly the National Polyp Study).
Sounds suspiciously like a meta-analysis. ;)

I think there are one or two studies in progress that are designed to answer the question directly.
I'll be interested to learn the results, particularly whether there is a correlation between removing very small growths -- such as 1-2 mm -- and cancer incidence.

[fls]

So waiting increases cancer incidence, but does not necessarily increase mortality?

Other studies show that it also increases mortality.

Sounds suspiciously like a meta-analysis. ;)

Not this one, but some of the other information in this thread (like info on the value of FOBT screening programs) came from systematic reviews.

I'll be interested to learn the results, particularly whether there is a correlation between removing very small growths -- such as 1-2 mm -- and cancer incidence.

How would that be relevant to your decision? We're not really talking about 1-2 mm growths, here.

Are you going somewhere with this? If you want to assure yourself that a different strategy is a reasonable choice, it is possible to do so. Don't think that you have to be locked into what I would choose for myself. :)

Linda

[PbFoot]

...came to him not cleaned or sanitized and in a state of advanced disrepair, well beyond where they'd be safe to use on a patient. When he went in for a colonoscopy himself, he insisted on disassembling and inspecting the unit that was to be used on him, beforehand.

I am a professional service technician for hospital sterilization equipment, and I often (almost every day) repair equipment used to clean and sterilize endoscopes.

There are some types of failures of endoscopes that, once the failure has occurred, preclude further cleaning or sterilization. Such a failure might be a cut in the light tube. If it were to be submerged in a cleaning solution, fluid would flood the electronics or other sensitive components of the scope. So, sometimes it's necessary to send it for repair with only an alcohol wipe down.

Like I said, I don't fix scopes myself, just the equipment used to sterilize them (and lots of other bio/pharma/medical gear). I can confirm that in a minority of hospitals there are some horrendous practices. I've seen some :jaw-dropp stuff. It's like those exposee shows where they go in to the kitchen of a bad restaurant. I must stress though, this is the minority. Most places are very good, and some are excellent - almost to the point of overkill.


-PbFoot

[Rodney]

Are you going somewhere with this? If you want to assure yourself that a different strategy is a reasonable choice, it is possible to do so. Don't think that you have to be locked into what I would choose for myself. :)
Costs aside, it seems to me illogical for an individual at low-risk for colon cancer to choose a regular colonoscopy over a virtual one, unless there is a significant benefit to removing polyps that cannot be seen by a virtual one. Even if there is, which I have not seen evidence for, it may be that there is a cut-off, wherein it may be beneficial to remove only those polyps that are, say, 4 mm or more -- and low-risk individuals may rarely have polyps of that size. Basically, what it comes down to for me, is that a regular colonoscopy is an invasive procedure that can be avoided by a safer, non-invasive procedure. However, I might change my mind if evidence develops that removing polyps of any size has significant benefits.