Wednesday, December 26, 2018
What Does Carl Sagan's Observation About The Effects of Medicine Really Mean?
I started reading Carl Sagan's book The Demon Haunted World based on what I heard about it on Twitter. Of course I was very familiar with his work based on his television persona but none of his writings. Part of the way in, I ran across the above quote as a footnote on page 13. It hit me immediately based both on my personal medical care and also the thousands of people I have assessed over the years. There was also a clear contrast with what is in the popular and professional press. The media has been obsessed with metrics of medical systems for various reasons. First, it is sensational. When they can get a hold of a controversial statistic like the estimated number of people killed by medical interventions every year. Change that to the equivalent number of 757 crashes per year and you have a hot headline. Second, generalizations about the quality of health care lack granularity and precision. There are no epidemiological studies that I am aware of that can even begin to answer the question he asked at the dinner party.
From a research standpoint, researching this endpoint would take an unprecedented level of detail. Standard clinical trials, epidemiological studies, and public health statistics look at mortality as an outcome typically of few variables and limited age groups. Nobody publishes any clear data on avoiding mortality - often many times over the course of a lifetime. The same is true about avoided morbidity. Researchers seem focused on binary outcomes - life or death, cured or ill, recovered or permanently disabled.
The closest literature seems to be the way that chronic illnesses accumulate over time but that endpoint is not as striking as a mortality endpoint. Every study that I have seen looks at specific cause of mortality or a collection of similar causes and not all possible causes. The best longitudinal data I have found is in a graph in this article in the Lancet (see figure 1). Please inspect this graph at the link and notice the trend in the number of chronic illnesses and how they increase with age. The population studied here was in Scotland. This is very impressive work because as far as my research goes I can find no other graph of chronic illnesses with this level of detail. Data in the US have very crude age groups and the number of chronic illness is often limited. If I look at CMS data for Medicare beneficiaries 34.5% have 0-1 chronic medical conditions, 29.5% have 2-3 conditions, 20.7% have 4 to 5 conditions, and 15.3 have 6+ conditions. By selecting certain age groups the percentages change in the expected directions. For example, looking at beneficiaries less than 65 years of age, 45% have 0-1 conditions and 11.2% have 6+ conditions.
Chronic conditions are the most significant part of medical effort and expenditure, but as indicated in Sagan's quote - they are only a part of the medical experience of people across their lifetimes. Now that some previously fatal conditions are being treated as chronic conditions the demarcation between morbidity and mortality is blurred even further. The experience of being treated and cured for a potentially fatal illness is left out of the picture. Being treated and cured from multiple fatal conditions over the course of a lifetime is also not captured. Two common examples are acute appendicitis and acute cholecystitis. These diagnoses alone account for 280,000 appendectomies and 600,000 cholecystectomies each year. The vast majority of those people go on to live normal lives after the surgery. Those surgical treatments are just a portion of the surgery performed each year that is curative and results in no further disability and in many situations the prevention of significant mortality and morbidity. A more complete metric of life saving, disability preventing, and disease course modification would be most useful to determine what works in the long run and where the priorities should be.
One way to get at those dimensions would be to look at what I would call the Sagan Index. Since I am sure that there are interests out there licensing and otherwise protecting Carl Sagan's name I am going to use the term Astronomer Index instead - but make no mistake about it - the concept is his.
I have included an initial draft of what this index might look like in the supplementary notes below. Higher number correlates with the number of times a life has been saved or disability prevented. Consider the following example - an average guy in his 60s. When I take his history he recalls being hospitalized for anaphylaxis at age 16 and a gangrenous appendix at 19. With the appendectomy he has a Penrose drain in his side and had a complicated hospital stay. He traveled to Africa in his 20's where he got peptic ulcer disease, malaria and 2 additional episodes of anaphylaxis from vaccines that he was allergic to. When he was 42 he had an acute esophageal obstruction and needed an emergency esophagoduodenoscopy. At age 45 he insisted on treatment for hypertension. At 50 he had polysomnography, was diagnosed with obstructive sleep apnea (OSA) and treated with continuous positive airway pressure (CPAP). At age 55 he had multiple episodes of atrial fibrillation and needed to be cardioverted twice. He is on long term medication to prevent atrial fibrillation. At age 60 he had an acute retinal detachment and needed emergency retinal surgery. At age 66 he needed prostate surgery because of prostatic hypertrophy and urinary tract obstruction. Assigning a point for either saving his life or preventing disability would yield a Astronomer Index of 11. In 5 of these situations he was likely dead without medical intervention (3 episodes of anaphylaxis, gangrenous appendix, and acute esophageal obstruction) and in the other six he would be partially blind, acutely ill with a urinary tract obstruction and possible renal failure, experiencing the cardiac side effects (or sudden death) from OSA, or possibly a stroke with disabling neurological deficits from the untreated atrial fibrillation. The index would take all of these situations into account as well as life threatening episodes of psychiatric illness or substance use.
Compare the Astronomer Index (AI) to all of the media stories about the number of medical errors that kill people. Preventing medical errors is an essential goal but it really does not give the average person a measure of how many times things go right. When I see stories about how many planes full of people die each year because of medical errors I think of a couple of things. The first is a NEJM article that came out in response to the IOM estimate of people dying from medical errors. It described the progress that had been made and what problems might be associated with the IOM report. The second thing I think of is the tremendous number of saves that I have seen in the patients I treat. I have to take a comprehensive medical history on any new patients that I assess and I have talked with many people who would score very highly on the AI.
Another aspect of treatment captured by this index would be the stark reality of medical treatment. The vast majority of people realize this and do not take any type of medical treatment lightly. There is a broad array of responses to these decisions ranging from rational decision making to denying the severity of the problem. Everyone undergoing medical treatment at some point faces a decision with varying degrees of risk. That should be evident from the current television direct-to-consumer pharmaceutical ads that rapidly list the serious side effects including death every time the commercial runs. The decisions that people make also have to answer the serious question of what their life would be like without the treatment and associated risk. There are no risk free treatments as far as I know. In the case of the hypothetical patient, he has taken at least 11 significant risks in consenting to medical and surgical treatment that have paid off by living into his seventh decade.
I have not seen any metric like AI applied across the population. Certainly there are many people who make it into their 60s and have fewer problems than in our example but there are also many who have more and actual disability. The available epidemiology of chronic, cured, and partially cured conditions is extremely limited and I don't see anything that comes close to a metric that captures an individuals lifetime experience like the AI index might. The rate of change in the index over the lifespan of the individual and across different populations might provide detailed information important for both prevention and service provision. In terms of psychiatric treatment - a good research question would be the response of people to treatment for psychiatric or substance use disorders with high scores on the index to people with low scores. Is there a potential correlation with cognitive decline?
The bottom line for me is that life is hard and most of us sustain considerable damage to our organism over the course of a lifetime. Only a small portion of that is covered in most medical and epidemiological studies. This index might provide the needed detail. It might also provide some perspective on how many times each of us need serious medical treatment over the course of a lifetime.
George Dawson, MD, DFAPA
1. Karen Barnett, Stewart W Mercer, Michael Norbury, Graham Watt, Sally Wyke, Bruce Guthrie,
Epidemiology of multimorbidity and implications for health care, research, and medical education: a cross-sectional study, The Lancet, Volume 380, Issue 9836, 2012, Pages 37-43,
A copy of the Astronomer Index (AI) is shown below: