Tuesday, March 27, 2012

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Monday, March 19, 2012

Random Medical Facts

     In the following, when I state a "fact", I am referring to a datum that has been verified in at least one double-blind clinical study. If I say there is "no evidence", I mean that there has been no such study. And I want to remind my readers that, as always, statistical correlation between condition or action A and disease B does NOT mean that A causes B----I refer you to Hume's "A Discourse Concerning  Human Understanding" for a further discussion of this as well as  the pitfalls inherent in reasoning by induction. Finally, absence of proof is not proof of absence, in that even though there may be no evidence that an intervention saves lives, the intervention may save lives nevertheless.

1) There is no evidence that an annual physical saves lives.

2) We do not know how often a patient should be brought back for evaluation for ANY condition, i.e. the optimum time interval to preserve the patient's health. We choose a time interval that "feels" right for pap smears,for blood sugar tests, for blood pressure checks, and the like.

3) A doctor seeing a patient with a physical complaint should always ask him/herself two questions: (a) is this patient ill enough to need hospitalization, and (b) what disease could the patient have that could kill him/her if I don't make the diagnosis and start treatment.

4) There is no evidence that total body CT scans saves lives.

5) There is no evidence that fast electron CT scans to evaluate cardiac calcium saves lives.

6) With the exception of a single abdominal ultrasound in males over the age of 65 who have hypertension there is no evidence that screening ultrasound Doppler studies of arterial flows saves lives.

7) Copper wrist bracelets do not treat/prevent arthritis.

8) A staple in your earlobe does not help you to lose weight.

9) The only guaranteed weight loss treatment, which also can reverse diabetes and bring the patient back to normoglycemia is stomach banding.

10) Every patient understates to the doctor the amount of cigarettes and alcohol consumed.

11) Virtually every patient has had or will have "unsafe sex".

12) Eight glasses of water or other fluid a day is not necessary for good health.

13) If you have a purely vegetarian diet with no vitamin supplements you will die from pernicious anemia.

14) All cigarette smokers will develop chronic emphysema and end their lives attached to an oxygen tank if they live long enough.

15) If you want to be tested for Sexually Transmitted Diseases, donate a unit of blood to the Red Cross or your hospital blood bank. Not only will they test your blood free of charge, there will also be no note or record of the test being done in your doctor's medical chart, and you will have helped your country.

16) Pregnant women have the keenest sense of smell of all. When a pregnant woman calls the gas company to say that she smells a gas leak, the repairman never leaves the house until the leak is found.

17) We don't know why some people sneeze uncontrollably when they leave a dark movie house in midday and their eyes are struck by the full force of the sun.

18) Please, please, please never look up your symptoms on the internet. EVERY complaint will be listed as possibly being due to AIDS or cancer, and usually Alzheimer's Disease as well. Please wait until you are given a diagnosis, and then look the diagnosis up.

19) One-half to one drink of any alcohol---beer, wine, whiskey--reduces the heart attack rate and increases your life span.

20) Coffee increases mental alertness, shortens eye-hand reaction time, reduces depression, treats asthma, and potentiates all pain medicines.

Wednesday, March 14, 2012

"To Sleep, Perchance to Dream"

     Once again a study on the use of hypnotics (aka "sleeping pills") has made its way into the headlines. This time it was an (online) publication of the British Medical Journal. Again, this study was a retrospective study, which compared patient who took sleeping pills with those who did not, and looked for clinical differences.

     As readers of my blog are well aware, I firmly believe that the results  of such studies should be used to generate a hypothesis, and not to come to a clinical conclusiuon, This hypothesis must then be tested in a forward study, i.e. now compare users of sleeping pills with non-users for the next two years. One of the most cited retrospective studies was a diet study of American females, which showed that those on a "low-fat" diet had a lower incidence of breast and colon cancer. A five-year study was then done, comparing the cancer rates of American females on a low-fat diet (defined as having fats make up less than 15% of their total daily calories) with those on their regular diet. NO DIFFERENCE was found  in the breast or colon cancer rates of these two groups. Nevertheless, the American Cancer Society still recommends a low-fat diet as a cancer preventative.

     There can always be confounding effects that invalidate a retrospective study. The first study of coffee drinkers showed that they had significantly more heart attacks than non-coffee drinkers. This created great alarm and various degrees of belief and disbelief, until one epidemiologist realized that more coffee drinkers smoke cigarettes than do non-coffee drinkers, and this was the overwhelming confounding factor and largest risk factor for heart attacks

     Insofar as sleeping pills and lack of sleep is concerned (I had written a blog on this in 2009) I am more concerned with the mental effects of lack of sleep than I am with the effects of sleeping pills. The federal government limits the number of hours per day and per week that an interstate trucker can drive as well as the number of hours a commercial pilot can fly. Healthy young medical interns are limited as to the amount of consecutive hours they can work whereas much older physicians such as myself have no such limitation.Lack of sleep impairs concentration, increases irritability, increases the errors made on the job, degrades ego functions, makes one more susceptible to depression, and decreases stamina. I would like to see a study comparing the cognitive functions of patients taking sleeping pills with a matched control group of sleep-deprived patients, to determine which group had the greater dimunition of CNS executive functions. Another study would be to compare  for two years  the health of an age-matched group wherein both asked for sleeping pills, and only half  of them were given the  prescription. Then we would have a direct comparison of underslept patients with those on sedative-hypnotics.