Vol. 165 March 15, 2017 Can Pregnancy Make You Stupid?

February 15, 2017

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“Most pregnant women will admit to bouts of “pregnancy brain” or “mommy brain” — whether it’s forgetting doctor’s appointments or forgetting their own phone number. This pregnancy-induced mental fog is part of the neurological changes at the start of pregnancy that continue throughout postpartum. ”

 

I am not at all sure that this phenomenon really exists, but scientists at Barcelona University recently published results from their study of 25 first-time pregnant women, the 25 fathers responsible for the pregnancies, and 20 non-pregnant childless women.  By comparing “before conception” and “postpartum” MRIs in the pregnant women the researchers documented a definite reduction in the pregnant women’s gray matter. The volume loss of gray matter occurred in three specific areas of the brain associated with social cognition and emotional feelings.  The differences of volume in the pregnant women was so apparent that the researchers could accurately pick which women were pregnant just by looking at the MRIs. Similar MRI imaging of the fathers and non-pregnant women showed no reduction of gray matter.

Gray matter is the part of the brain cortex that is mostly neuronal cells. White matter consists mostly of connections between the neuronal cells, axons (“wires”) coated with white myelin. The reduction of gray matter in the pregnant women was in brain areas associated with “being able to think about how other people feel and perceive things.” and persisted for 2 years after delivery.

Using fMRI (functional MRI – measures brain activity not just structure) these reduced gray matter areas would “light up”, show higher metabolic activity, when the mother gazed upon a picture of her own baby rather than a picture of someone else’s baby. The researchers speculated that this was a measure of quality “mother-infant attachment”.

The implication of this gray matter reduction is not clear. Many past studies in all kinds of people suggest strongly that people with larger volume of gray matter have better memory and are happier.

A study of ultra-marathoners (ran 2,788 miles in 64 days without a rest day) showed a reduction of gray matter of 6%, but it was reversed in 6 months and was not associated with any brain lesions. In comparison to the less than 0.2% per year gray matter reduction in the elderly this 6% is H-Y-U-G-E. Pre- and post-run Cognitive tests would have been help in this study of ultra-marathoners, but I am not sure you could detect any increase in stupidity in them. Presumably the reversible reduction in brain volume was due to dehydration.

Studies of chronic marijuana users show reduction in gray matter, but increased “connections”, and no loss of cognitive skills (if not high at the time of testing). This and similar findings in adolescent brains have been explained as either a bad thing about marijuana use or as a “maturation” of the brain as it gets “better organized” for specialized tasks. A similar explanation of an “organizing process”, “a pruning toward a more efficient brain” is offered by the researchers of these pregnant women.

So where does this leave us regarding permanent gray matter reduction in pregnant women? We, of course, don’t really know at this point. fMRI studies are still in their infancy, and there is some controversy about what they really mean. But, cognitive tests of both these pregnant and non-pregnant women showed no difference, and no change in cognitive functions after delivery, so we can confidently say that pregnancy does NOT make you “stupid”… or even “stupider”.


Vol. 164 March 1, 2017 The Exercise Paradox

January 31, 2017

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“You can’t outrun a bad diet”

It appears that an African native chasing a wounded giraffe through the bush and over the plains for 12 hours in order to get food for himself and his family burns the SAME NUMBER OF CALORIES per day as the modern couch potato. Researchers measuring the urine excretion of two radioactive isotopes of water ingested by the subjects (the “gold standard” of measuring energy expenditure) have confirmed this fact as postulated previously by several studies. These African hunter-gatherers burned about 2,600 calories a day, about the same as average adults in present day U.S. and Europe.

The researchers were looking to measure the size of the “energy shortfall” in Westerners to explain the global rise of obesity. They found none. In fact, another review of almost a hundred (98) world-wide studies of energy expenditure (calories burned per day) revealed that “the persons with all the modern conveniences have similar energy expenditures to those with more physically demanding lives in less developed countries.”  Therefore, “obesity is a disease of gluttony, not sloth.”

Physical activity does NOT cause weight loss, but exercise can help prevent weight gain.  A JAMA 2010 study of 34,000 middle-aged U.S. women showed that 60 minutes a day of moderate exercise (walking) prevented weight gain in those on a normal diet who had previously lost weight through dieting.

As someone who collected articles about  bad things happening to joggers to justify my ignoring Society’s “persistent call to go running”, this is music to my ears. The evidence that exercise, including just walking, is good for you is absolutely true and well accepted. It just doesn’t help you lose weight. Again, as someone who has made a resolution every January to lose weight by going to the gym only to peter out by the end of every March, this made me feel less inadequate, or at least less guilty.

Humans have a fixed rate of energy expenditure which is independent of their physical activity. A subsequent study of 300 people wearing Fit-bits showed that those doing moderate activity  (some exercise and always taking the stairs) burned only 200 more calories than couch potatoes. People doing intense physical activity did NOT burn more calories than the moderately active people. Again, the African bushman burns the SAME number of calories walking a mile as does the Westerner.

Studies of energy expenditure in zoo animals compared to animals in the wild reveal the same constancy. How can this be? No one really knows, but the authors speculate that since human energy expenditure is quite constant (and constrained), we modern adults who are not chasing wounded giraffes over the veld have evolved metabolic adaptations that spend our calories on supporting brain functions (the oxygen you take in with every fourth breath is needed just to feed your brain) , running our inflammatory processes (exercise may prevent inflammation by diverting energy from it), producing more and bigger babies, and living longer. But, I am not sure that I am any smarter than the African bushman who lives to 70 in his world, and many of them do.

Humans have learned to cook which increases the caloric value of many foods and makes them more efficiently digested.
We also have evolved to be fat. Our tendency to store fat is probably an adaptation for surviving lean times.
During lean times our survival is enhanced by us sharing what food there is.
Apes do not share.

“Exercise to stay healthy and vital;
focus on diet to look after your weight.”

References:
1. The Exercise Paradox, Herman Pontzer, Scientific American, Feb. 2017, 28-31


Vol. 161 January 1, 2017 Recap of 2016 Hubslist Blogs

January 1, 2017

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“Don’t look back.
Something may be gaining on you.”
-#6 of Satchel Paige’s Guides to Good Living

Click on the date to view the entire blog.

January 1 –   “How bad is the heroin epidemic on a scale from 1 to 10?” Could physician compliance with the patient-reported pain scale have contributed to the over prescription of opioids?

February 1 –  From Z to A – Zika virus to autism with G and F for gluten-free diet in the middle.

February 15 – The “single blood drop” lab test that never panned out (my largest pile of misplaced enthusiasm and the poorest stock tip ever) and “Uber Doctor”.  The founder of Theranos was banned from engaging in any laboratory business for 2 years.

March 1 – “Smith” as the most likely name of your doctor went from #1 in 1930-39 to #4 in 1980-89, replaced by “Patel”, “Shah”, and “Lee”. The largest contingent (20%) of foreign-born U.S. physicians came from India during that period.

March 15 – Health apps (and now Alexa apparently) are not “secure” since they transmit data about your personal use back to company headquarters (at least, not to the NSA … we think)

April Fools Day – TrumpaCare Health Plan Revealed. It doesn’t read quite as tongue-in-cheek now as it did then.

April 15 – The bathroom bill and how diclofenac killed all the vultures in India and why that matters.

May 1 – Multiple private insurance companies pull out of Obamacare (ACA) which somehow continued to be attacked as a “socialistic, single-payor” scheme.

May 15 – Medical fun facts about three presidents and Obama’s prediction in third grade about becoming President and “visiting all the places in Indonesia”.

June 1 – Placebos work better as therapy if they cost more. The Chinese reduced adult myopia by getting the kids to play outside more often while 40% of U.S. toddlers (under 2 yo.) already play with an electronic mobile device.

June 15 – Annual update on sun and bugs … actually anti-sun and anti-bugs.

July 15 – Medication Assisted Treatment (MAT) of opioid/heroin addiction works pretty well without making the patient lie down. So, more beds are NOT needed and are NOT the answer.

August 1 – Five reasons that playing video games improves learning in kids… IF the content is right.

September 1 – Various “redefinitions” of medical “truths” about teen age pregnancies, blood pressure medicines, and lead exposure.

September 15 –  How to be an appropriately skeptical reader of media reports of “medical advances” … aka “Beware of Percentages” in hyped reports of improved outcomes.

October 1 – “Light up or not.” Pros and cons of recreational marijuana referenda on 8 state ballots.

October 15 – Asking your doctor to make you a “DNT ” after “a certain age”. Nine medical tests that can be optional after 65 because their benefits are elusive and results may cause more problems than they are worth. Choose Wisely website.

November 1 – A really scary clown CAN kill you. The same physiological mechanism may have caused Debbie Reynolds’ sudden death while she was planning Carrie Fisher’s funeral.

November 15 – Real health CARE reform is the way to improve on the health care INSURANCE reform of Obamacare.

December 1 – Less old people are leaving their car keys in the refrigerator while Germany and Japan residents gain more weight in a year than we do.

December 15 –  Though the stakes are high (lack of health insurance causes 45,000 unnecessary deaths in the U.S.) it will probably take two years for Trump and the Republican Congress to turn back the accomplishments of Obamacare.
I am hoping that as an unintended consequence of their reframing of the ACA, the law will actually be improved.

HAPPY NEW YEAR from an eternal optimist.


Vol. 157 November 1, 2016 Can You Be Scared To Death?

November 1, 2016

Hub thumbnail 2015BOO!!

 Did I Scare You?

Can you be scared to death?
The short answer is yes, absolutely.

Dr. Martin Samuels, Chief of Neurology, Brigham and Women’s Hospital summarized the mechanism in Scientific American  as the familiar “fight-or-flight” response. The outpouring of adrenaline in our blood in response to stress can inundate the rhythm center of the heart, causing it to lose control, resulting in ventricle fibrillation and persistent contraction or “cramping” of the heart muscle. That stops the effective pumping of our heart, and we drop dead. (1)

The “flight-or-flight” response was first described in the early 1900’s by William Cannon, Chairman of Physiology, Harvard University. It can be in reaction to any strong emotional event, pleasurable as well as not-so-pleasurable. It may cause sudden death during a passionate religious experience or sexual intercourse. I have written previously about increased cardiac deaths in both Germany and Los Angles related to close soccer championship and American  Super bowl games. During the week after 9/11 there was an uptick of cardiac deaths in New York city. Apparently, even getting a hole-in-one can kill you!  It is this mechanism that explains the limited successes of voodoo curses, but unlike other forms of complimentary medicine like acupuncture and Reiki you have to believe in voodoo to have it work.

So much for the medical side of things. What does the law say? Can you be sued or charged with a crime if your action leads to a person’s death? It depends on your intent.

If you inadvertently harm a person you must likely will be held harmless. If you intentionally surprise or seek to scare a person and they die, you can be charged with “negligence” and found guilty.  In 1979 a 20 yo.man who broke into the home of a 79 yo. woman and took her hostage was sentenced to life imprisonment in federal court after she died from a heart attack while in his custody. But, the actual charges were “kidnapping” and “negligence” – failure to seek treatment for her.

What about just a good old fashioned  “blood-curdling scream”? Well, that can cause you trouble too.  Dutch physicians studied 24 healthy volunteers and found that viewing a scary movie, like “Halloween 1, or 2, …#13”,  could cause the initiation of the “coagulation cascade” in their blood. This cascade involves multiple “factors” (proteins) that cause us to form a clot when cut, so that we don’t bleed to death from a simple cut. The cascade is started by Factor VIII, and Factor VIII levels increased by an average of 11 units after viewing a horror film. No increase was seen after watching an educational film. An increase of 10 units of Factor VIII increases your chance of forming a blood clot by 17%. (2) Forming a blood clot inside a vein can lead to a pulmonary embolism, another cause of sudden death in apparently healthy people.

If you are reading this blog it means that you have survived the creepy clowns and other scares of Halloween 2016, but don’t be smug.
The Presidential election is just days away, so you are still at risk of being “scared to death” by a clown.

HAPPY HALLOWEEN

REFERENCES:
1.’
“Can a Person Be Scared to Death?”, Scientific American, January 30, 2009
2.  “Blood Curdling Movies”, British Medical Journal, December 16,  2015


Vol. 156 October 15, 2016 Adding “DNT” to Your Medical Record Before “DNR”

October 15, 2016

 

Hub thumbnail 2015At our last weekly gathering of the “Over 70 Men’s Breakfast Club” we heard from one of us the following about visits to two of his physicians on the same day a week before:

Gastroenterologist: “Congratulations, your colonoscopy was entirely normal.”
Patient: “Great. When should I schedule the next one?”
Gastroenterologist: “Well ,, er..um .. you are over 75 you know. At your age it …er…um.. wouldn’t make any difference.”

The same day with his primary care physician:

Patient: “I think my urine stream is slowing a bit. How’s my prostate?”
PCP: “Your prostate exam is absolutely normal.”
Patient: “What about a PSA test?”
PCP: “ We don’t do those for men your age. It …er…um…wouldn’t make any difference in the long run. Oh, by the way, who’s your Health Care Proxy, the person who can make you DNR in case you can’t speak for yourself?”

Over our eggs and bacon (one member, our oldest, has oatmeal and berries instead) we reached the consensus that his medical record should be stamped with a “DNT: Do Not Test”.

Here are some of the “unnecessary” screening tests that he and others “of certain ages” should skip:

PSA: Rarely done under 50 yo. or over 70 yo. and now being questioned as of mixed benefit for any man. Screening does not reduce the very, very low death rate from prostate cancer and false positives are common. Further investigations of false positive results can cost at least $1,200 per patient, and treatment of truly positive cases can cause incontinence and/or impotence without any significant medical benefit.

Colonoscopy: rarely done under 50 yo. and never over 75 yo. as a screening test. Repeat colonoscopy after an initial normal one detects cancer of the colon no better than a periodic fecal occult blood (FOB) test on a stool sample done by your primary doctor.

X-ray, CT scan or MRI for low back pain without other symptoms: Back pain usually gets better in a month whether you have imaging done or not. Surgery is often done on image irregularities which have no causal relationship to the pain.

Pap smear: Every 3 years for ages 21 to 30. Every 5 years from 31 years to 65. None after 65 yo. “Abnormal” but non-cancerous cells can be detected by this test, but do not need treatment. Pap smears are recommended even if the woman receives the HPV vaccine (Gardasil) because the vaccine does not cover all viruses that cause cervical cancer.

Vitamin D: Vitamin D is the current “vitamin in vogue”. Speculations about relationships with heart and other diseases are riff, but the data is not that conclusive. Many people have low vitamin D levels (as currently defined) but very low levels associated with real illness are extremely rare. Oral vitamin D treatment has not been shown to reliably raise vitamin D levels. A 10 minute walk in the sun and a breakfast with orange juice and eggs supply more than enough vitamin D. (Note: The blood test itself is not expensive, but in 2011 Medicare paid $224 million for vitamin D screening on seniors.)

Testosterone level:  Despite the plethora (I am told) of late night TV ads selling gels, patches, and pills for low testosterone among middle age and older men, treatable “low testosterone” is rare.  Unless a man has one or two of 9 specific symptoms ( and erectile dysfunction (ED) is NOT one of them) a testosterone blood level screen is not recommended. Even if the level is low (under 10 nmol/L – I’m not sure what these units are either, except that they are very small ) a treatable diagnosis rests on the clinical history and exam, not the blood test.

Bone Density: Never under 50 and rarely over 70 in men without risk factors like fractures, heavy smoking or drinking, or very low Vit. D levels. Women could get one done at age 65, but  “treatment” of low bone density with costly medications (also advertised a lot on TV) has not been shown to have much benefit.

Annual EKG or stress test: Does not add any useful information for the asymptomatic person.

Whole Body Scans: Besides the cost and the large amount of radiation involved, these scans should be avoided because they do NOT find asymptomatic cancer. Less than 2% of the scans find a true mass and most of those are benign or inconsequential. In over 33% of scans “abnormal findings”, sometimes called “ditzels” by radiologists, lead to unnecessary and expensive further imaging tests that do not result in any benefit to the patient. (This test was previously heralded by this blog as a good Christmas present for an enemy)

References:

1. Choose Wisely is a list of unnecessary medical tests complied by the American Board of Internal Medicine from suggestions of numerous other specialty groups and published widely in Consumer Reports and other periodicals.


Vol. 155 October 1, 2016 Legalizing Recreational Marijuana?

October 1, 2016

Hub thumbnail 2015Massachusetts voters and 7 other states will be voting November 8 on proposed laws “legalizing, regulating, and taxing Marijuana”. All of these “binding” Questions have been placed on the ballots by “Initiative Petition” (grassroots’ signature campaigns … no pun intended).The proposed Massachusetts law will legalize for anyone 21 or older the possession of 1 ounce of marijuana outside a residence or up to 10 ounces inside a residence, of up to 6 marijuana plants, and of GIVING without payment 1 ounce or less to another person 21 or older. The actual bill fills 11 full pages which reflects not only the controversial issues surrounding the bill, but also the complexities of proposed regulations and taxation.  

Colorado legalized recreational marijuana four years ago, and its experiences (both positive and negative) are currently feeding both sides of the debate of the economic, social, and political consequences.

I will only summarize some of the medical issues (“the News”) with scant remarks about some other issues (”the Editorial”).

Marijuana is a gateway drug: Not really
Physician researchers studying substance abuse ( at least those pediatrician-scientists who present at conferences in Boston) consider nicotine, alcohol, and marijuana as almost equivalent “initial drugs of choice” in adolescents and young adults who become addicted to heroin or opiates. They speak of marijuana “heavy-users” ( more than one joint daily), not marijuana “addicts”, and they represent a small percentage of adolescent MJ users.

Marijuana is addictive: Maybe a little
About 9-10% of users become “dependent”, “need to have daily MJ to feel normal”. Those who start using MJ under the age of 21 are more likely to become dependent. The withdrawal symptoms when heavy users stop after many years are much less than those who stop use of opiates, heroin, alcohol, or even nicotine. No medications are necessary, and any troublesome symptoms usually respond to cognitive behavioral therapy (talking to a therapist). “Addictive behavior” such as crimes to obtain money and violent acts are not usually associated with MJ dependency.

Marijuana is safe: Yes
Lester Grinspoon, MD in his landmark books, “Marijuana Reconsidered” (1971) and “Marihuana (sic): The Forbidden Medicine ” (1991), stated that no one has ever died of a  marijuana overdose, and that statement still stands true.

Marijuana changes your brain: Yes, if under 21 yo.
This reason and the dangers of small children eating large amounts of edible MJ are the reasons the American Academy of Pediatrics opposes the legalization of MJ but NOT its decriminalization.

The Academy also recommends that marijuana be decriminalized, so that penalties for marijuana-related offenses are reduced to lesser criminal charges or civil penalties. Efforts to decriminalize marijuana should take place in conjunction with efforts to prevent marijuana use and promote early treatment of adolescents with marijuana use problems.”

Heavy use  of MJ before the age of 21 can change how the brain functions as revealed by functional MRIs (fMRI).  Heavy MJ use can actually change brain structure in areas associated with impulse control and “executive functions”. Some studies show a lowering of IQ by 8-9 points in heavy users. The long term effects of these structural changes in adolescents are being studied, but everyone seems to agree that MJ use should not be legalized for those under 21 years of age.

Marijuana can impair your driving: Perhaps
Studies do show that MJ can prolong your reaction time and reduce attention span (less so than alcohol – check out this YouTube video), so the opponents of legalization believe that the law will lead to more car accidents. The data on actual accidents, whether fatal or not, is not so clear. There is no standard method to measure “MJ intoxication”. Blood and urine tests measure MJ metabolites which can be present for up to 45-50 days after smoking a single joint (depending on age, weight, and belt size). These tests, since they depend on measuring metabolites, may not even turn positive until 24-48 AFTER a new user smokes a joint. Such tests can identify regular users, but there is no correlation between blood and urine test levels and the actual degree of impairment.  Remember, even the “gold standard” in drunk driving cases, Breathalyzer results, are not permitted to be entered as evidence in court because of variations in calibration and field administration.


The Massachusetts Medical Society opposes  the legalization of recreational marijuana because of 1) “the addictive nature of marijuana”, 2) “the adverse effects on developing brains”, and 3) “the appeal of edibles to youngsters”.

The effect of legalization on youth access to marijuana is a controversial subject that is dismissed by pediatric researchers.

“Adolescents and pre-adolescents already have open access to MJ. Legalizing it won’t change that.”
It is worth remembering that Dr. Grinspoon got interested in the medical effects of marijuana when his son was undergoing chemotherapy, and MJ reduced his nausea greatly. Lester’s wife easily bought that MJ in a Newton schoolyard in the 60s.

That reality that MJ distribution and sales will become a big business is why proponents are pushing its tax revenue upside. Opponents are concerned that “Big Tobacco” or other nefarious organizations will take over the MJ market.

My vote:
I will vote “NO” on Question 4 in Massachusetts proposing the  “Legalization, Regulation, and Taxation of Marijuana” primarily because of its unknown consequences that should become clearer in time (even just a year or two would help). Also, our state’s less than stellar track record in satisfactorily implementing the much smaller program of legalizing medical marijuana ( 59 pages of regulations in 2013 and several public missteps) gives me real pause about how it could all play out.

I think that the recreational use of marijuana will eventually be legalized in Massachusetts, and that there can be some real benefits of such a change.  But, I also think that there is too much that is vague and/or capable of manipulation in this proposed law, even at 11 pages long.


Vol. 154 September 15, 2016 READER BEWARE, Take a Grain of Salt With Media Hype About Medical Advances

September 15, 2016

Hub thumbnail 2015Headlines that tout a new drug or a new procedure which is “much better” than the old one are very common in our media. Some of them are true. Some of them are misleading. Most of them depend on the definition of “better” in the research study or clinical trial. A recent issue of the New England Journal of Medicine reviewed the “changing face of clinical trials” and outlined in detailed, technical language what their readers (physicians and other health professionals) should look for in published studies and clinical trials to confirm that the simplified “positive outcome reported” is significant and relevant. (1)

It inspired me to give similar “heads-ups” to my more general readers so they might be better evaluators of media announcements and commercials about medical advances.

Be skeptical about percentages
“Drug A has 50% less side effects than Drug B” or “Drug A is 50% more effective than Drug B.”
If 2 out 100 patients had a side effect with Drug A and Drug B side effects happened in 4 of 100 patients, that is a 50% reduction of a very low occurrence event, and it is probably not relevant.

“Antibiotics reduced the time out of work (or out of school, or days of fever) by 50%”.
This could mean “time absent” went from 2 days to 1 day, not all that significant considering the cost and potential side effects of antibiotics.

For those of you who want to dig deeper you should ask for the P value of the positive outcome. A statistical P value of 0.05 means that the difference between the two treatments is not enough to say that one was better than the other. The difference is “not significant”. In medical studies the test of a true difference is a P value of less than 0.001; written as P<0.001. That difference is “significant”. Looking at P values is an easy way to avoid the illusionary trap of percentages.

“Dementia Incidence is Decreasing!”
This was the February 2016 “headline”, admittedly in the back pages or side bars, in several newspapers and magazines. It was based on data from the ongoing, well-respected Framingham Heart Study that has been studying the same people since 1975. The article listed declines of 22%, 38%, and 44% each epoch (an epoch is about 15 years) from 1975 to 2010 in 5205 persons over 60 years old.
Looks impressive!
Again the percentages.
The actual incidence went from 2.8 per 100 persons demonstrating dementia to 2.0 per 100. These numbers seem a bit less dramatic to me. To top it all off, the risk reduction was observed in ONLY those who had at least a high school diploma. I’m glad that I am in that population subgroup, but that suggests an issue about the relevance of study results to the general population.

Is the positive outcome of the study clinically relevant?
Tests of some new drugs treating diabetes have shown a much better control of blood sugars, but NO reduction in cardiovascular events and even a HIGHER mortality rate.

Certain cancer tests may be shown to find cancers earlier, but there is no reduction in patient morbidity and mortality. The PAS test for prostate cancer “found” a lot more cases of prostate cancer, but did not result in any reduction of deaths from prostatic cancer. Later studies even showed that the PAS test often resulted in unnecessary further tests and treatment, so the age criteria recommendations for obtaining a PAS were changed in 2012.

Multiple studies of ICU patients have shown “better” physiological or laboratory value resulting from selected treatments, but NO change in length of stay or mortality rates in those patients receiving the new treatment.

Is the study large enough to be reliable?
This can be tricky. The study should involve enough patients to be statistically sound (there’s the old P<0.001 value again), but big numbers are not a guarantee. A recent article on the effectiveness of CPAP (continuous positive airway pressure) treatment for Obstructive Sleep Apnea (OSA) was based on studying close to 2500 patients. Sounds big to me, but look how they got to that number.

15,325 patients were assessed for eligibility in the study.
.        
9481 declined to participate or were excluded for other reasons
leaving 5844 that met the study’s diagnostic criteria
.         2598 were then excluded for having too mild symptoms
leaving 3246 who entered a one-week trial period
.          
529 were then excluded for poor compliance or other reasons
leaving 2717 patients that were randomized into the study
.            
30 were then excluded from the analysis for a variety of reasons
leaving 1346 receiving the new treatment and 1341 receiving standard treatment
.            62 receiving the new treatment discontinued
            85 receiving the standard treatment discontinued.
Resulting in 1284 analyzed for the new treatment and 1256 analyzed for the standard treatment.

Besides suggesting how difficult the logistics of a clinical study can be, a markedly descending number of study participants like this can raise concerns about a selection bias of patients, or as they say, “There’s many a slip twixt the cup and the lip.”

Oh, yeh, the results of the study?
“CPAP treatment significantly (P<0.001 again) reduced snoring and daytime sleepiness, but did not prevent cardiovascular events (P values 0.96 to 0.07)”.


Also there were so many variables in this complex study like “duration of use” (3.3 hrs. a night average) , “degrees of compliance” with protocols, different “severity of symptoms”, etc. that the NEJM felt compelled to publish in the same issue an editorial suggesting caution about the impact of this study on current clinical practice (see comments about clinical relevance above).

Conclusion:
More often than not the new procedure or the new drug is more expensive than the “old” one. That adds another reason to ask your doctor if it is really better than the previous one. Remembering that “if it happens to me it’s 100%”, what is the patient  supposed to do? How can we evaluate this bombardment of new advances?

“Ultimately, physicians at the point of care bear the final responsibility for accurately interpreting clinical trial results and for integrating regulatory and guideline recommendations to make the best treatment decisions for each patient in their care” (1)

References:
1. “The Primary Outcome is Positive – Is That Enough?”, New England Journal of Medicine, Sept. 8, 2016, 375;10 p.371


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