I suspect that many of you have seen or read about a recent study regarding the “long COVID” enigma. The investigators surveyed the records of more than 4000 pediatric patients who had been infected and nearly 1400 who had not. The researchers then developed models in which 14 symptoms were more common in previous SARS-CoV2–infected individuals in all age groups, compared with the uninfected. There were four additional symptoms in children only and three additional symptoms in the adolescents.
Using these data, the investigators created research indices that “correlated with poor overall health and quality of life” and emphasized “neurocognitive, pain, and gastrointestinal symptoms in school-age children” and a “change or loss in smell or taste, pain, and fatigue/malaise-related symptoms in adolescents.”
Dr. William G. Wilkoff
So now thanks to these investigators we have research indices for characterizing PASC (post-acute sequelae of SARS-CoV-2, aka. long COVID). What should we to do with them? I’m not sure these results move us any further if our goal is finding something to help patients who believe, or have been told, that they have long COVID.
Even to a non-statistician like myself there appear to be some problems with this study. In an editorial accompanying this study, Suchitra Rao, MBBS, MSCS in the Department of Pediatrics, University of Colorado School of Medicine, Aurora, noted the study has the potential for ascertainment bias. For example, the researchers’ subject recruitment procedure resulted in a higher “proportion of neurocognitive/behavioral manifestations” may have skewed the results.
Also, some of the patient evaluations were not done at a consistent interval after the initial infection, which could result in recall bias. And, more importantly, because there were no baseline measurements to determine preinfection status, the investigators had no way of determining to what degree the patients’ underlying conditions may have reflected the quality of life scores.
Although I wouldn’t consider it a bias, I wonder if the investigators have a preconceived vision of what long COVID is going to look like once it is better understood. The fact that they undertook this project suggests that they believe the truth about the phenomenon will be discoverable using data based on collections of vague symptoms.
Or, do the researchers share my vision of long COVID that if it exists it will be something akin to the burst of Parkinson’s disease seen decades later in survivors of the 1918-1920 flu pandemic. Or, maybe it is something like post-polio syndrome, in which survivors in childhood develop atrophy and muscle weakness as they age. Do the researchers believe that COVID survivors are harboring some remnant of SARS-CoV-2 or its genome inside their bodies ticking like a time bomb ready to surface in the future? Think shingles.
I suspect that there are some folks who may or not share my ticking time bomb vision, but who, like me, wonder if there is really such a thing as long COVID – at least one in the form characterized by the work of these investigators. Unfortunately, the $1 billion the National Institutes of Health has invested in the Researching COVID to Enhance Recovery (RECOVER) initiative is not going to discover delayed sequelae until time is ready to tell us. What researchers are looking at now is a collection of patients, some who were not well to begin with but now describe a collection of vague symptoms, some of which are unique to COVID, but most are not. The loss of taste and smell being the one notable and important exception.
It is easy to understand why patients and their physicians would like to have a diagnosis like “long COVID” to at least validate their symptoms that up until now have eluded explanation or remedy. Not surprisingly, they may feel that, if researchers can’t find a cure, let’s at least have something we can lay the blame on.
A major flaw in this current attempt to characterize long COVID is the lack of a true control group. Yes, the subjects the researchers labeled as “uninfected” lived contemporaneously with the patients unfortunate enough to have acquired the virus. However, this illness was mysterious from its first appearance, continued to be more frightening as we struggled to learn more about it, and was clumsily managed in a way that turned our way of life upside down. This was particularly true for school-age children. It unmasked previously unsuspected underlying conditions and quickly acquired a poorly documented reputation for having a “long” variety.
Of course the “uninfected” also lived through these same tumultuous times. But knowing that you harbored, and may still harbor, this mysterious invader moves the infected and their families into a whole new level of concern and anxiety the rest of us who were more fortunate don’t share.
We must not ignore the fact that patients and their caregivers may receive some comfort when they have something to blame for their symptoms. However, we must shift our focus away from blame hunting, which up to this point has been fruitless. Instead, Each patient should be treated as an individual and not part of a group with similar symptoms cobbled together with data acquired under a cloud of bias.
Dr. Wilkoff practiced primary care pediatrics in Brunswick, Maine, for nearly 40 years. He has authored several books on behavioral pediatrics, including “How to Say No to Your Toddler.” Other than a Littman stethoscope he accepted as a first-year medical student in 1966, Dr. Wilkoff reports having nothing to disclose. Email him at pdnews@mdedge.com.