I have received a number of questions about the latest Cochrane report about the purported uselessness of annual physicals, so I thought I should analyze the report for my readers. (My earlier thoughts were posted in an earlier blog, entitled The Annual Physical.) For those of you who are not familiar with the Cochrane system, it is similar in concept to the group of French mathematicians who have published articles for over 50 years under the pen name Bourbaki. The Cochrane group is an international non-profit organization. It has a fluid makeup and a number of different participants, and devotes itself to finding the best proven treatment or diagnostic process for a given disease or symptom, based on clinical studies. They publish a book each year under the auspices of the British Medical Journal, and when you read the book you are led to realize how few of our medical methods are well-grounded in clinical fact. As I have often mentioned before, what seems "obvious" often does not stand up under clinical studies, e.g. the proper treatment to reduce the number of calcium oxalate kidney stones you produce is to INcrease the amount of calcium in your diet, not to decrease it. I should also mention that the calcification of your coronary arteries proceeds independently of the amount of calcium in your diet.
A good summary of the Cochrane report to which I refer was published online by Med Page Today on October 16, 2012, at http://www.medpagetoday.com/PrimaryCare/GeneralPrimaryCare/35356. The study was a meta-analysis (and see my previous blog on that subject with an analysis of the weaknesses of such a study) of 16 clinical trials involving over 180,000 patients. The endpoint they looked at in 8 studies was cardiac mortality and in 8 studies was cancer mortality. They found that patients who had regular health checkups died from both causes at the same rate as those who did not have an annual physical, and they also did not have less disability.
There are several logical errors in this analysis. To begin with, since the mean time of the studies was 9 years, they could not test for total mortality, i.e. extension of one's lifespan. Secondly, many patients go for screening studies such as a pap smear and a mammogram without having an annual physical. Thirdly many patients take themselves to cardiologists of their own accord, and periodic cardiology visits were not counted as a regular health checkup any more than was a visit to one's gynecologist. The conceptual problem with all the studies is that no attention was paid as to how a potentially fatal disease or condition was discovered. We do know that certain interventions save lives, so that people who see a doctor, even aperiodically, live longer than people who never see a doctor. Therefore the questions devolves upon when and how often a patient should be examined by a doctor, and whether the schedule of the visits should be rigidly time-ordered, or one should wait for the patient to come in. At what time interval does a periodic physical exam of a patient with no complaints begin to save lives? This is the basic unanswered question.