If we’re changing guidelines, it’s because we’re learning as we go along

Published August 19, 2020, 9:49 AM

by MB Lifestyle

Recommendations change as science evolves, not because we make mistakes


By Dr. Edsel Maurice T. Salvana, MD, DTM&H, FPCP, FIDSA

Medicine is a messy business. As an infectious disease physician, I deal with a multitude of viruses, bacteria, fungi, and other organisms that cause disease. Textbooks describe the classic symptoms of these illnesses. For instance, dengue usually causes fever for about five days, then platelets start to drop two days after the fever goes away. Most people recover. They test positive for dengue NS1, IgM, and eventually IgG most of the time. Occasionally, you’ll get the patient who has only two days of fever, but the platelet count is critically low and all the tests are negative. Still, you are pretty sure it is dengue based on having seen hundreds of these patients and you treat accordingly. This is called a clinical diagnosis.

Dr. Salvana at TedGlobal 2017. Photo by Bret Hartman/Ted

Clinical diagnosis is an art and a science. You take the disparate parts of a patient’s history, physical examination, and laboratory results and stitch them into a pattern that will tell you what the patient has and how best to treat it. 

This is necessary because of two things: The virus never read the textbook and the patient never read the textbook. Medicine and science work on probabilities. For dengue, most patients will have fever, most will have low platelet counts, and most will test positive on the laboratory tests. Some of these, however, will not be present and, in rare cases, may even be contradictory. This is where clinical experience—having seen hundreds of cases and a diversity of patterns—helps doctors decide the best treatment for a patient. Medicine is not a perfect science and therefore what we call the “clinical eye” can mean the difference between getting the correct diagnosis and treatment and missing a crucial diagnosis. It is what makes Filipino doctors, especially those who train at large government hospitals, so exceptional. 

In the five years a medical student spends at these institutions, he/she sees thousands of patients with a huge variety of ailments. The lack of resources for laboratory studies makes a Filipino doctor rely on the clinical eye more than most.

The emergence of a novel coronavirus with which no one has had any experience certainly had us on the ropes early in the pandemic. At the start, mortality rates were between five to 10 percent. We learned quickly, and now more people are surviving. As a testament to how good Filipino healthcare workers are, despite having over 160,000 cases we have had less than 3,000 deaths. Among the top 25 countries with over 100,000 cases, we have the second lowest absolute number of deaths. What about the lowest and the third lowest? These are Qatar and Saudi Arabia, whose healthcare systems are mostly manned by Filipino doctors and nurses. The two countries ranked below us, Indonesia and Canada, have more than twice (6,000) and three times (9,000) the number of deaths. Aside from having benefited from one of the earliest and harshest lockdowns in the world, our healthcare workers are giving unmatched care to their patients worldwide.

Our cases, however,  are now surging. Whether it is because of opening up the economy, a more infectious virus, or less than ideal mitigation programs is difficult to tease out. Maybe it is all three. Coupled with a low healthcare system capacity that is about 10 percent of that of the United States, the absolute number of severe and critical cases will increase, and they will have nowhere to go. 

Even the world-class care of Filipino healthcare workers will be unable to save patients if there are not enough ventilators, critical care beds, or medication. The only way to prevent more deaths is to turn to evidence-based interventions that will interrupt transmission. Fortunately, we know what works. Mask use, eye protection, and physical distancing can decrease the risk of transmitting Covid-19 by up to 90 percent. But only if we use these correctly and consistently. This means getting everybody to use them by using a carrot-and-stick approach. The saying “You can only lead a horse to water,” implying that people can be led to a solution but not be forced to take it applies here. This is when the art of medicine comes in, and this includes the ability to persuade the patient to accept your treatment. Science will tell you the medicine or the method works. For the truly relevant outcomes, which are whether a patient lives or dies, and whether someone gets Covid-19 or not, this means doctors need to look beyond the usual practice of medicine and guide our patients to the correct decision predicted by probability, even if we don’t know the complete picture ourselves. 

Missteps will be made as we find out more about the virus. Doctors and scientists expect this. Clinicians sometimes must contend with seemingly contradictory data and rely on past experience with similar situations to move forward. What the public finds difficult to understand is that science is dependent on observations and that recommendations change as the science evolves. The shift from recommending masks only for symptomatic patients and then later requiring it for everyone else confused most people, and anti-science pundits were quick to jump on this to attack the scientific establishment’s standing. The recommendation changed when peer-reviewed studies found that Covid-19, unlike SARS and MERS, can be transmitted even before symptoms manifest. This was only discovered through careful observation and follow-up. Doctors and scientists do not have an emotional connection to their guidelines. As newer data becomes available, we change the guidelines. 

Hydroxychloroquine was widely used early on, but we have now stopped using it since the randomized controlled trials showed no benefit. We were unsure about steroid use before, but after the recovery trials showed that it decreased deaths among critically ill patients, it is now standard of care. Change is accepted based on best available evidence.

We know from experience that all pandemics will end. The only question is how many people will die. That is the stark clinical outcome. The best way to decrease deaths is by listening to the science, even as it changes constantly. Doctors and scientists need to convince the public and the government to use these science-based approaches, and even walk back those that are later proven to be ineffective, without losing credibility. This is a tall order, especially with all the noise on social media and rampant political polarization in a lot of countries.

Ultimately, restoring and maintaining trust in science is incumbent upon the public becoming science-literate and being able to independently assess what is and is not supported by the evidence. It is looking beyond the headlines and forming a discerning opinion about what is being reported. It is taking the data, warts and all, and understanding what it is truly saying, what it is not saying, and what it cannot say. It’s just like a doctor making a diagnosis and deciding on the best possible treatment. In the end, it is the clinical outcome that matters. 

Edsel Maurice T. Salvana, MD, DTM&H, FPCP, FIDSA is an internationally recognized infectious diseases specialist and molecular biologist at the University of the Philippines Manila and the Philippine General Hospital. He is the director of the Institute of Molecular Biology and Biotechnology at the National Institutes of Health at UP Manila. He is a senior TED fellow and adjunct faculty for global health at the University of Pittsburgh.