The April 24, 2006 issue of the Archives of Internal Medicine published a study from Australia that examined the effects of a twice daily supplement of 600 mg. of calcium carbonate on fracture rates and bone density.
This was a 5 year, double blind, placebo-controlled trial of 1660 women older than 70 years of age.
They found:
1.Using an intention-to-treat analysis, supplementation did not significantly reduce fracture rate.
2.But, of the 56.8% of the study participants who actually took the calcium, there was a reduced fracture rate ( hazard ratio 0.66) and improved bone density measurements.
So when viewed from a "public health perspective" it was not effective. However, calcium seems to work if you take the pills.
These results are similar to those of the recently published Woman's Health Study which also demonstrated that pills only work when you take them. Unlike the U.S. study this one did not find an increase in kidney stones. The misread and sometimes mis-reported results of the WHS may have lead some to stop their calcium in the belief that calcium supplemention does not help.
It does seem to decrease risk of fracture and it may even reduce the risk of colon polyps.
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Friday, April 28, 2006
More on bribing doctors to do their job
I recently posted on Dr. Faith Fitzgerald's principaled stand against pay for performance(P4P).
Ironically in the same issue of Internalmedicinenew.com, as Dr. Fitzgerald's article Dr. Christine K Cassel is featured promoting the ABIM scheme to tie "voluntary" reporting of quality data to obtain points to be used to obtain internist recertification and alleged future remuneration from Medicare.
The measurement of quality indicators is part of the ABIM's Practice Improvement Models (PIMs).
Dr. Cassel is trying to sell all of this because the collected quality data can be used"for multiple purposes."
Dr. Fitzgerald talked about "tipping doctors"for doing their duty.So far as regards CMS,there is just a promise of possible tipping in the future. ABIM seems to be making "an offer you can't refuse" by the threat of non-re certification for docs who don't play their quality game.
Some of us remember Dr. Cassel's commentary in the Annals of Internal Medicine in which she supported a flawed Annals article which bashed older docs in which she took the opportunity to promote the ABIM recertification dicta. See here for Dr. Roy Poses's comments regarding that issue. Promoting physician autonomy and the individual doctor patient relationship clearly is not part of the ABIM mission.
Ironically in the same issue of Internalmedicinenew.com, as Dr. Fitzgerald's article Dr. Christine K Cassel is featured promoting the ABIM scheme to tie "voluntary" reporting of quality data to obtain points to be used to obtain internist recertification and alleged future remuneration from Medicare.
The measurement of quality indicators is part of the ABIM's Practice Improvement Models (PIMs).
Dr. Cassel is trying to sell all of this because the collected quality data can be used"for multiple purposes."
Dr. Fitzgerald talked about "tipping doctors"for doing their duty.So far as regards CMS,there is just a promise of possible tipping in the future. ABIM seems to be making "an offer you can't refuse" by the threat of non-re certification for docs who don't play their quality game.
Some of us remember Dr. Cassel's commentary in the Annals of Internal Medicine in which she supported a flawed Annals article which bashed older docs in which she took the opportunity to promote the ABIM recertification dicta. See here for Dr. Roy Poses's comments regarding that issue. Promoting physician autonomy and the individual doctor patient relationship clearly is not part of the ABIM mission.
Thursday, April 27, 2006
Another argument against pay for performance (P4P) Should doctors be tipped?
Dr. Faith Fitzgerald,professor of Medicine at UC Davis,speaks out against P4P in the April 13,2006 issue of Internal Medicine News.(www.internalmedicinenews.com)
She makes two major points.
1)recommendations by "expert"panels are subject to reversal due to the fragile and provisional nature of medical conventional wisdom. Physicians feel bad when they make certain recommendations ( e.g. HRT for postmenopausal women) and later learn they may have harmed their patients, but at least they thought they were doing the right thing based on the information available at the time. However, with P4P, " Shall we have the same solace if we make these decisions,not because we think they are right but for money?
2"...the very concept of pay for performance for doctors,especially we when collaborate in the creating of the concept:Pay for performance embodies the tacit assumption that if we are not delivering it, it is because we are not being paid enough."...it[P4P] corrodes the conception of self-governance and correction that is part of the definition of professional. ...We must not servilely accept gratuities for doing our duty."
I believe P4P is wrong on so many levels. Thanks to Dr. Fitzgerald for emphasizing the aspect of how P4P is antithetical to physicians' professional identity.
She makes two major points.
1)recommendations by "expert"panels are subject to reversal due to the fragile and provisional nature of medical conventional wisdom. Physicians feel bad when they make certain recommendations ( e.g. HRT for postmenopausal women) and later learn they may have harmed their patients, but at least they thought they were doing the right thing based on the information available at the time. However, with P4P, " Shall we have the same solace if we make these decisions,not because we think they are right but for money?
2"...the very concept of pay for performance for doctors,especially we when collaborate in the creating of the concept:Pay for performance embodies the tacit assumption that if we are not delivering it, it is because we are not being paid enough."...it[P4P] corrodes the conception of self-governance and correction that is part of the definition of professional. ...We must not servilely accept gratuities for doing our duty."
I believe P4P is wrong on so many levels. Thanks to Dr. Fitzgerald for emphasizing the aspect of how P4P is antithetical to physicians' professional identity.
Tuesday, April 25, 2006
JAMA article:more on why single disease guidelines don't work for multi disease and frail patients
Thankfully,more and more authors of medical journal articles are pointing out the obvious-single disease guidelines applied by role to complicated patients is not a good thing. Clinical judgment is actually required.
In the April 26.2006 issue of JAMA, Dr. Samuel C. Durso writes about the issues involved in using clinical guidelines for older patients with diabetes and complex health status.He referenced an article called "Guidelines for Improving the Care of the Older Person with Diabetes Mellitus." The JAMA article and by reference the "guidelines" he discusses seem to really be a permission to deviate from various single disease guidelines as the physician and patient attempt to do what seems best for the patient taking into consideration prioritizing goals and the patient values and wishes reminding me of Dr. Norton Hadler's "clinical truth".
There have been earlier articles critical of the rote use of single disease guidelines in patients with multiple diseases and this article's focus in on older diabetic patients and highlights problems in frail patients with short life expectancies.
Here are some quotes from Durso's article:
"Most clinical guidelines for common conditions are disease-focused and do not provide guidance for prioritizing multiple medical conditions including geriatric syndromes that are common in older adults."
"Nor do most guidelines make explicit provisions for addressing a patient's health care preferences when they differ from guideline recommendations."
The closing sentence is interesting:
"Clinicians also must be trained in complex decision making"
It that not what internists had been trained to do over the years?
I am a bit taken back that he seems to be talking about " guidelines for guidelines"(I do not believe there can be an algorithm for everything) but there is clear value in recognizing the importance of placing guidelines in the overall clinical picture and knowing when to hold them and when to fold them.
In the April 26.2006 issue of JAMA, Dr. Samuel C. Durso writes about the issues involved in using clinical guidelines for older patients with diabetes and complex health status.He referenced an article called "Guidelines for Improving the Care of the Older Person with Diabetes Mellitus." The JAMA article and by reference the "guidelines" he discusses seem to really be a permission to deviate from various single disease guidelines as the physician and patient attempt to do what seems best for the patient taking into consideration prioritizing goals and the patient values and wishes reminding me of Dr. Norton Hadler's "clinical truth".
There have been earlier articles critical of the rote use of single disease guidelines in patients with multiple diseases and this article's focus in on older diabetic patients and highlights problems in frail patients with short life expectancies.
Here are some quotes from Durso's article:
"Most clinical guidelines for common conditions are disease-focused and do not provide guidance for prioritizing multiple medical conditions including geriatric syndromes that are common in older adults."
"Nor do most guidelines make explicit provisions for addressing a patient's health care preferences when they differ from guideline recommendations."
The closing sentence is interesting:
"Clinicians also must be trained in complex decision making"
It that not what internists had been trained to do over the years?
I am a bit taken back that he seems to be talking about " guidelines for guidelines"(I do not believe there can be an algorithm for everything) but there is clear value in recognizing the importance of placing guidelines in the overall clinical picture and knowing when to hold them and when to fold them.
Sunday, April 23, 2006
Medscape offers pro and con discussion re" P4P
I have to give credit to Medscape for publishing arguments against pay for performance (P4P) in the form of a point-counterpoint piece.
Dr. Robert M Centor, professor at University of Alabama and president elect of the Society of General Internal Medicine (and well known blogger) presented a well reasoned discussion pointing out concerns and problems regarding P4P.I believe internists and family physicians who populate the real world of patient care will be heartened by the position he presented.
Dr. Michael S.Barr,one of the vice presidents of the American College of Physicians, was assigned the job of delivering the ACP party line and what appeared to me to be a rather luke warm defense of P4P-"Many physicians have indicated significant concerns about P4P, and rightly so."
Barr does not address the points made by Centor(in fairness this was not a debate with time for rebuttals) but relies on giving a version of recent history of the issue which as usual begins with a mandatory reference to the seemingly-above-challenge "Crossing the Quality Chasm " authored by the IOM and advice to physicians to "reframe their thinking."
No doubt, there are thoughtful physicians and others who believe the P4P will improve quality but I cannot but think that the major driver for this movement is to reduce costs. The major players in that regard are the government, insurance and HMOs and with their resources seem to dominate the debate and have largely defined the universe of discourse regarding the issue.(Note-even I have given up bothering to put quotes around the word quality.)
Dr.Centor, in his role at the Society of General Internal Medicine,does have a forum to express his views and I applaud his efforts and hope others can join the fray.
Dr. Robert M Centor, professor at University of Alabama and president elect of the Society of General Internal Medicine (and well known blogger) presented a well reasoned discussion pointing out concerns and problems regarding P4P.I believe internists and family physicians who populate the real world of patient care will be heartened by the position he presented.
Dr. Michael S.Barr,one of the vice presidents of the American College of Physicians, was assigned the job of delivering the ACP party line and what appeared to me to be a rather luke warm defense of P4P-"Many physicians have indicated significant concerns about P4P, and rightly so."
Barr does not address the points made by Centor(in fairness this was not a debate with time for rebuttals) but relies on giving a version of recent history of the issue which as usual begins with a mandatory reference to the seemingly-above-challenge "Crossing the Quality Chasm " authored by the IOM and advice to physicians to "reframe their thinking."
No doubt, there are thoughtful physicians and others who believe the P4P will improve quality but I cannot but think that the major driver for this movement is to reduce costs. The major players in that regard are the government, insurance and HMOs and with their resources seem to dominate the debate and have largely defined the universe of discourse regarding the issue.(Note-even I have given up bothering to put quotes around the word quality.)
Dr.Centor, in his role at the Society of General Internal Medicine,does have a forum to express his views and I applaud his efforts and hope others can join the fray.
Wednesday, April 12, 2006
What could be better than a Randomized Clinical Trial?
What would be better than a RCT? Answer- a RCT that makes a comparison between realistic alternatives. This issue was the subject of a insightful editorial in the April 12, 2006 issue of JAMA.(Recent Trials in Hypertension-compelling science or commercial speech;JAMA, vol 295, no. 14, p1704-1706)
Three researchers well known for their expertise in this area authored the piece,B.M. Psaty,N.S. Weiss and C. D Furberg.
Full text requires subscription. Here are some highlights.
We are all becoming increasingly aware that a RCT comparing two drugs does not mean squat if the comparator drug is given in too low a dose or is one that no one (or hardly anyone) would choose anyway.
Is one treatment superior to another? Lets do a RCT. O.K. but " a fundamental principle of active treatment-controlled trials is the scientific obligation to use the best available treatment in the control group."
The editorialists were addressing the issue of blood pressure active treatment trials (an active treatment trial compares one drug with another- not with a placebo) and point out that in the ASCOT trial, low dose diuretics were not used in 45% of the atenolol group.Further,the ASCOT investigators acknowledged that possibly atenolol was not the appropriate comparator drug
for contemporary BP treatment. (Atenolol has fallen into some disrepute in that regard)
One point is that one could argue that low dose diuretics would have been a more appropriate comparator drug and atenolol is not the best beta-blocker to use as well.
Comparing drugs or sequences of drugs in hypertension trials is not simple.Many- if not most- patients require two or more medications to achieve control and the protocols in active comparisons trials may not reflect the way BP is really treated in the non-RCT world in which real physicians live. The highly hyped and highly criticized ALLHAT trial has also been accused of that fault.
The authors point out that although atenolol does not have a great track record in decreasing cardiovascular disease mortality in treated hypertensive patients, 3 large recent industry-sponsored trials used atenolol as the comparator drug.
The editorial quotes a recommendation of the National Heart,Lung and Blood Institute Working Group proposing a comparison of several drugs in patients who were receiving low dose diuretics, i.e. adding on an ARB, or an ACEi, or a CCB or a beta-blocker (but not atenolol) and doing a head-to-head comparison.
Three researchers well known for their expertise in this area authored the piece,B.M. Psaty,N.S. Weiss and C. D Furberg.
Full text requires subscription. Here are some highlights.
We are all becoming increasingly aware that a RCT comparing two drugs does not mean squat if the comparator drug is given in too low a dose or is one that no one (or hardly anyone) would choose anyway.
Is one treatment superior to another? Lets do a RCT. O.K. but " a fundamental principle of active treatment-controlled trials is the scientific obligation to use the best available treatment in the control group."
The editorialists were addressing the issue of blood pressure active treatment trials (an active treatment trial compares one drug with another- not with a placebo) and point out that in the ASCOT trial, low dose diuretics were not used in 45% of the atenolol group.Further,the ASCOT investigators acknowledged that possibly atenolol was not the appropriate comparator drug
for contemporary BP treatment. (Atenolol has fallen into some disrepute in that regard)
One point is that one could argue that low dose diuretics would have been a more appropriate comparator drug and atenolol is not the best beta-blocker to use as well.
Comparing drugs or sequences of drugs in hypertension trials is not simple.Many- if not most- patients require two or more medications to achieve control and the protocols in active comparisons trials may not reflect the way BP is really treated in the non-RCT world in which real physicians live. The highly hyped and highly criticized ALLHAT trial has also been accused of that fault.
The authors point out that although atenolol does not have a great track record in decreasing cardiovascular disease mortality in treated hypertensive patients, 3 large recent industry-sponsored trials used atenolol as the comparator drug.
The editorial quotes a recommendation of the National Heart,Lung and Blood Institute Working Group proposing a comparison of several drugs in patients who were receiving low dose diuretics, i.e. adding on an ARB, or an ACEi, or a CCB or a beta-blocker (but not atenolol) and doing a head-to-head comparison.
Senator raises questions about the quality of Quality Improvement Organizations ( QIOs)
Probably most people and likely many physicians have never even heard of QICs. Here is their website where we learn that the QIC program is directed by CMS and consists of 53 QICs who are tasked "to make sure patients get the right care at the right time."
Senator Chuck Grassley is asking for changes in this program because- according to a recent news blurb in the Capital Health Call section in JAMA of "questionable expeditures,potential conflicts of interests and lack of effectiveness." He raises questions about the quality of the program purported to ensure quality of medical care.
The American Health Quality Association, which is described as a QIC trade organization seems to admit that the program need changes-probably they would favor more funding- but blames the problems on poorly written laws.
Purportedly, there was a need for these QICs because physicians left to their own devices would not deliver "quality care", so it would seem reasonable that what we need now is another layer of quardians who can watch over and insure the quality of the organizations that were to insure the quality of care., but ,of course, they will have to be audited.
Senator Chuck Grassley is asking for changes in this program because- according to a recent news blurb in the Capital Health Call section in JAMA of "questionable expeditures,potential conflicts of interests and lack of effectiveness." He raises questions about the quality of the program purported to ensure quality of medical care.
The American Health Quality Association, which is described as a QIC trade organization seems to admit that the program need changes-probably they would favor more funding- but blames the problems on poorly written laws.
Purportedly, there was a need for these QICs because physicians left to their own devices would not deliver "quality care", so it would seem reasonable that what we need now is another layer of quardians who can watch over and insure the quality of the organizations that were to insure the quality of care., but ,of course, they will have to be audited.
Tuesday, April 11, 2006
More on Disease Mongering
Health Care Renewal recently referenced a symposium on Disease Mongering (DM) and the full text essays are now available on the PLOS website.
In recent months,I have written about certain aspects of the promotion of the diagnosis and treatment of two conditions,bipolar disorder and restless legs syndrome (RSL) as having features of the DM phenomenon.
Let me attempt to preempt one line of possible criticism by stipulating that Bipolar Disease is a very serious psychiatric disorder and warrants treatment by qualified physicians and that RLS can be in some patients a very disturbing disorder with definite morbidity relief from which could be very worthwhile.
However, I had questioned the drug company initiative to round up primary care doctors to seek out and take on the often daunting task of managing a bipolar patient,an enterprise in which psychiatrists really earn their fee.(I will admit that in No-trees Texas type locations the PCP may have to take on the job as the region may be bereft of psychiatrists).I also questioned the wisdom of screening for RLS with a drug company sponsored questionnaire with the objective of offering treatment with a dompamine agonist for positive screenees.
The PLOS symposium essay on RLS is worth reading as it takes up several aspects of this matter with much greater development of the issues than my gut feeling sense of it that I posted. Hats off to Doctors Steven Woloshin and Lisa M. Schwartz of Dartmouth Medical School .
Another article questions the evidence or lack of it underpinning the whole issue of diagnosis and treatment of bipolar disorder.
It can be argued that the marketers manipulate the motivations of physicians and various support groups . The physicians are obviously an essential element in the equation. It is their desire to foster the welfare of their patient and do the right thing that is necessary for the DM process to flourish. I believe the "shame of being ignorant" is branded into the limbic cortex of medical students .Hats off to the ever insightful author of the blog PURRY GUD (tomwaitsatemyaby.blogspot.com) who used that phrase recently.
Physicians-many at least-are haunted by the fear that we will harm someone or fail to help someone because of something we do not know (there are certainly other ways we can harm also). This motivation to know what we need to know allows marketers to direct our energies to detection of new illness and to accept wider definitions of disease . Medications are not prescribed because we like the free food or notepads or pens even if we like the free food. Free lunches are not really the problem. The marketers not only manipulate the physcians' hypertrophied sense of duty but the prestige of evidence based medicine as well with all the tricks and traps one can squeeze into a randomized trial to give the veneer of solid science to something that may be no more than a comparison of their drug with one no one would use anyway.
The good news here, if there is any, is that we are catching on. The DM symposium is evidence of that.
We are getting more skeptical about what we read.We are realizing there is more to a RCT than the fact is randomized and blinded. With Google and other search engines it is easier to more quickly confirm or deny material from various promotional efforts. (The bad news is who has time to check and analyze everything that appears in print)
But even as our duty pushes us to strive even harder to figure out what it is we should do to do the right thing we learn of still another tactic to thwart and divert our efforts.
In recent months,I have written about certain aspects of the promotion of the diagnosis and treatment of two conditions,bipolar disorder and restless legs syndrome (RSL) as having features of the DM phenomenon.
Let me attempt to preempt one line of possible criticism by stipulating that Bipolar Disease is a very serious psychiatric disorder and warrants treatment by qualified physicians and that RLS can be in some patients a very disturbing disorder with definite morbidity relief from which could be very worthwhile.
However, I had questioned the drug company initiative to round up primary care doctors to seek out and take on the often daunting task of managing a bipolar patient,an enterprise in which psychiatrists really earn their fee.(I will admit that in No-trees Texas type locations the PCP may have to take on the job as the region may be bereft of psychiatrists).I also questioned the wisdom of screening for RLS with a drug company sponsored questionnaire with the objective of offering treatment with a dompamine agonist for positive screenees.
The PLOS symposium essay on RLS is worth reading as it takes up several aspects of this matter with much greater development of the issues than my gut feeling sense of it that I posted. Hats off to Doctors Steven Woloshin and Lisa M. Schwartz of Dartmouth Medical School .
Another article questions the evidence or lack of it underpinning the whole issue of diagnosis and treatment of bipolar disorder.
It can be argued that the marketers manipulate the motivations of physicians and various support groups . The physicians are obviously an essential element in the equation. It is their desire to foster the welfare of their patient and do the right thing that is necessary for the DM process to flourish. I believe the "shame of being ignorant" is branded into the limbic cortex of medical students .Hats off to the ever insightful author of the blog PURRY GUD (tomwaitsatemyaby.blogspot.com) who used that phrase recently.
Physicians-many at least-are haunted by the fear that we will harm someone or fail to help someone because of something we do not know (there are certainly other ways we can harm also). This motivation to know what we need to know allows marketers to direct our energies to detection of new illness and to accept wider definitions of disease . Medications are not prescribed because we like the free food or notepads or pens even if we like the free food. Free lunches are not really the problem. The marketers not only manipulate the physcians' hypertrophied sense of duty but the prestige of evidence based medicine as well with all the tricks and traps one can squeeze into a randomized trial to give the veneer of solid science to something that may be no more than a comparison of their drug with one no one would use anyway.
The good news here, if there is any, is that we are catching on. The DM symposium is evidence of that.
We are getting more skeptical about what we read.We are realizing there is more to a RCT than the fact is randomized and blinded. With Google and other search engines it is easier to more quickly confirm or deny material from various promotional efforts. (The bad news is who has time to check and analyze everything that appears in print)
But even as our duty pushes us to strive even harder to figure out what it is we should do to do the right thing we learn of still another tactic to thwart and divert our efforts.
Monday, April 10, 2006
Medical news you really can't use
Medical Journals sometimes publish POEMs-which in this context stands for "Patient Oriented Evidence that Matters". The criteria for a study to be elevated to high level on the epistemological food chain are:
1.addresses a question physician face.
2.has measure(s) of outcome and
3.has the potential to change the way doctors practice.
There are several "medical news newspapers" typically distributed without charge to physicians, one example of which is the " Internal Medicine Report",which I usually read if for no other reason than for the excellent essays by Dr.Philip R. Alper . This type of publication has no shortage of information that you really can't use,as well as some you can , the trick being to know the difference.
Here are some of the "unPOEMs" from that publication.
They reference an case control study from Urology (2005,67:73-79,which noted that risk for BPH was increased by eating more cereal,bread, eggs and poultry while risk was decreased by eating more soup,legumes, cooked veggies and citrus fruit. Try putting this factoid into your practice. Mr. Jones, with your BPH- I would recommend you eat less bread and more soup.
Another reference was to a paper presented at meeting of the American Stroke Association in which patients who had endovascular closure of patent foramen ovale (PFO) has less migraine headache than a comparison group that was treated medically.This was a retrospective,nonrandomized study and recall bias was an obvious issue. Again try and put this "observation" into practice.
In the same issue we also "learn" that Sulfonyluea therapy for type 2 diabetes linked to cancer" and "moderate coffee consumption may keep Type 2 diabetes "at bay".
Many of these factoid unPOEMs derive from case control studies that are correctly described as hypothesis generating studies that sometimes alert researchers to apparent associations that lead them to push on with more definitive techniques and sometimes are just statistical noise dead ends.
1.addresses a question physician face.
2.has measure(s) of outcome and
3.has the potential to change the way doctors practice.
There are several "medical news newspapers" typically distributed without charge to physicians, one example of which is the " Internal Medicine Report",which I usually read if for no other reason than for the excellent essays by Dr.Philip R. Alper . This type of publication has no shortage of information that you really can't use,as well as some you can , the trick being to know the difference.
Here are some of the "unPOEMs" from that publication.
They reference an case control study from Urology (2005,67:73-79,which noted that risk for BPH was increased by eating more cereal,bread, eggs and poultry while risk was decreased by eating more soup,legumes, cooked veggies and citrus fruit. Try putting this factoid into your practice. Mr. Jones, with your BPH- I would recommend you eat less bread and more soup.
Another reference was to a paper presented at meeting of the American Stroke Association in which patients who had endovascular closure of patent foramen ovale (PFO) has less migraine headache than a comparison group that was treated medically.This was a retrospective,nonrandomized study and recall bias was an obvious issue. Again try and put this "observation" into practice.
In the same issue we also "learn" that Sulfonyluea therapy for type 2 diabetes linked to cancer" and "moderate coffee consumption may keep Type 2 diabetes "at bay".
Many of these factoid unPOEMs derive from case control studies that are correctly described as hypothesis generating studies that sometimes alert researchers to apparent associations that lead them to push on with more definitive techniques and sometimes are just statistical noise dead ends.
Sunday, April 09, 2006
Carotid endarterectomy-AAN guidelines
The updated and long awaited guidelines from the American Academy of Neurology are available on line in full text. Their previous guidelines were published in 1990.
Two large Class I studies provide good data for their recommendations regarding symptomatic carotid stenosis (CS), the NASCET trial and the ECST. Entry into the studies required a TIA or non-disabling stroke within the previous 6 months.
For symptomatic patients with stenosis greater than 70% ( but less than "near total" occlusion) carotid endarterectomy (CE) is recommended if the surgical stroke or death frequency is believed to be less than 6% and the patient has an expected survival of five years or more. The absolute risk reduction is 16% with a NNT of 6.3.
If the stenosis is less than 50%, surgery is not recommended and medical treatment is preferred.
In regard to asymptomatic patients CE should be considered if the stenosis is 60-99 % and the surgical stroke or death risk is less than 3% and the patient has an expected 5 year or greater survival.
Due to the slow accumulation of big time Class I studies we may have gone about as far as we are likely to go any time soon with learning about CE versus medical treatment, but what about carotid stents? The jury is just beginning to hear the evidence and there are advocates with convincing arguments on each side.
Coronary stents have certainly become worthy rivals of CABGs and catheter treatment of cerebral aneurysms -at least in some clinical situations-may be better than surgical clipping. I believe that increasingly we will see more and more endovascular catheters at work and less classical surgery. I wonder how long it will take for enough data with head to head ( or neck to neck) comparisons between CE and stenting to accumulate to determine the role of catheters versus surgery in this setting.
Two large Class I studies provide good data for their recommendations regarding symptomatic carotid stenosis (CS), the NASCET trial and the ECST. Entry into the studies required a TIA or non-disabling stroke within the previous 6 months.
For symptomatic patients with stenosis greater than 70% ( but less than "near total" occlusion) carotid endarterectomy (CE) is recommended if the surgical stroke or death frequency is believed to be less than 6% and the patient has an expected survival of five years or more. The absolute risk reduction is 16% with a NNT of 6.3.
If the stenosis is less than 50%, surgery is not recommended and medical treatment is preferred.
In regard to asymptomatic patients CE should be considered if the stenosis is 60-99 % and the surgical stroke or death risk is less than 3% and the patient has an expected 5 year or greater survival.
Due to the slow accumulation of big time Class I studies we may have gone about as far as we are likely to go any time soon with learning about CE versus medical treatment, but what about carotid stents? The jury is just beginning to hear the evidence and there are advocates with convincing arguments on each side.
Coronary stents have certainly become worthy rivals of CABGs and catheter treatment of cerebral aneurysms -at least in some clinical situations-may be better than surgical clipping. I believe that increasingly we will see more and more endovascular catheters at work and less classical surgery. I wonder how long it will take for enough data with head to head ( or neck to neck) comparisons between CE and stenting to accumulate to determine the role of catheters versus surgery in this setting.
Tuesday, April 04, 2006
You need more than FEV1 to judge bronchodilator response
Bronchodilator drug trials and often clinical followup have focused on the changes in the forced expiratory volume in one sec (FEV1) to judge therapeutic response. However, it is recognized that exercise intolerance and dyspnea may improve with no significant change in expiratory flow rates.
Improvement in exercise tolerance actually seems to correlate better with indicators of improvement in overinflation,a simple measure of which is the inspiratory capacity (IC).
The IC is the sum of the tidal volume and the inspiratory reserve capacity which is the volume of air inhaled on top of a tidal volume. In COPD the IC is reduced as a result of the hyperinflation ( increased residual volume and functional residual capacity) so that the tidal volume is performed at the upper part of the lung's pressure volume curve which is a region of low compliance and an increased load on the inspiratory muscles.The overinflation present at rest is worsened with increasing airtrapping during exercise with increased respiratory rate and decreased time to exhale and is currently thought to be a major variable that relates to exercise intolerance and the sensation of dyspnea.
In the March 2006 issue of Chest ( subscription required for full text), authors from Holland demonstrated that a long acting bronchodilator (LABA),formoterol plus once a day tioptropium ( a long acting anticholinergic) brought about significant improvement in expiratory flow rates and -probably more importantly from a symptom improvement point of view-a significant increase in the inspiratory capacity.
Scores of bronchodilator trials focused only ( or at least mainly) on FEV1 measurement. ( I was involved in several as a pulmonary fellow) and as we learn more about the pathophysiology and the clinical correlates of lung function measurements we are better able to develop therapeutic measures to improve the disabling exercise intolerance of COPD patients.
It may have taken the surgical lung volume reduction experience to remind lung doctors that we have been doing pharmcologic lung volume reduction therapy all along when we have been using bronchodilators.
Improvement in exercise tolerance actually seems to correlate better with indicators of improvement in overinflation,a simple measure of which is the inspiratory capacity (IC).
The IC is the sum of the tidal volume and the inspiratory reserve capacity which is the volume of air inhaled on top of a tidal volume. In COPD the IC is reduced as a result of the hyperinflation ( increased residual volume and functional residual capacity) so that the tidal volume is performed at the upper part of the lung's pressure volume curve which is a region of low compliance and an increased load on the inspiratory muscles.The overinflation present at rest is worsened with increasing airtrapping during exercise with increased respiratory rate and decreased time to exhale and is currently thought to be a major variable that relates to exercise intolerance and the sensation of dyspnea.
In the March 2006 issue of Chest ( subscription required for full text), authors from Holland demonstrated that a long acting bronchodilator (LABA),formoterol plus once a day tioptropium ( a long acting anticholinergic) brought about significant improvement in expiratory flow rates and -probably more importantly from a symptom improvement point of view-a significant increase in the inspiratory capacity.
Scores of bronchodilator trials focused only ( or at least mainly) on FEV1 measurement. ( I was involved in several as a pulmonary fellow) and as we learn more about the pathophysiology and the clinical correlates of lung function measurements we are better able to develop therapeutic measures to improve the disabling exercise intolerance of COPD patients.
It may have taken the surgical lung volume reduction experience to remind lung doctors that we have been doing pharmcologic lung volume reduction therapy all along when we have been using bronchodilators.
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