We commend Romero et al [1] for exploring the impact of the COVID-19 pandemic on acute surgical disease. They noted an increase in the proportion of cases that were graded as severe on CT scan and concluded that delays in seeking medical care led to increasing severity of acute appendicitis at the time of presentation. Use of proportions, however, is vulnerable to changes in both numerator and denominator. Although raw numbers are not included in the article, based on Figure 1, we can estimate the number of patients who presented within each severity category during the pandemic and nonpandemic periods. In fact, there was no difference in the number of patients presenting with grades 4 and 5 acute appendicitis when the nonpandemic period is compared with the pandemic period (24 versus 23 patients).∗ What the authors observed was not an increase in severe cases but a decrease in mild cases.
The authors posit pandemic-related delays in care resulted in more severe disease. However, when one considers the raw numbers, other potential explanations arise. It is possible that more patients with mild, self-limiting disease recovered at home during the pandemic period and those with severe disease continued to present despite pandemic-related limitations on access to medical care. Previous work has suggested that mild, self-limiting appendicitis may, in fact, be a different disease compared with severe, perforated cases [2,3], which would support this explanation. Similar decreases in overall appendicitis cases were noted in our own study of five institutions across the United States [4] and in a multicenter study in Jerusalem, Israel [5]. In these studies, as seems to be the case in the current study, changes were driven primarily by decreases in mild appendicitis cases with few changes in volume of severe cases.
Relying exclusively on proportions of severe appendicitis without investigating changes in both numerator and denominator risks missing half the story. Per Strengthening the Reporting of Observational Studies in Epidemiology guidelines for observational research, raw numbers should be included to place any summary statistics, such as proportions, into appropriate context [6]. For appendicitis, the denominator (all cases of acute appendicitis) seems susceptible to health care utilization—among other factors. Recognizing divergent trends in severe and mild forms of this disease may deepen our understanding of its natural history and pathophysiology.
Acknowledgment
Miriam Y Neufeld is supported, in part, by a T32 training grant (GM86308).
Footnotes
The authors state that they have no conflict of interest related to the material discussed in this article. Dr Neufeld, Dr Sanchez, and Dr Drake are nonpartner, non–partnership track employees.
We based this calculation on the data presented in Figure 1 [1]. Nonpandemic (total N = 135): grade 4 is approximately 15% (20 patients) and grade 5 is approximately 3% (4 patients), for a total of 24 patients with severe disease. Pandemic (total N = 54): grade 4 is approximately 35% (19 patients) and grade 5 is approximately 8% (4 patients), for a total of 23 patients with severe disease. Grade 4 is described as ruptured appendicitis, and grade 5 is “complicated appendicitis.” Of note, when the authors “dichotomized” their results into nonsevere and severe disease, it seems that grade 3 (“appendicitis with peri-appendicitis”) was included in the severe category. From a clinical or surgical standpoint, peri-appendicitis is quite a broad category, although presumably most of these patients could still have a straightforward operation. From the standpoint of our calculation, including grade 3 would actually have led to a larger number of “severe” patients in the nonpandemic period, further emphasizing the point of this letter. However, we based our calculation on grades 4 and 5 because, from a clinical standpoint, these are patients with truly severe disease.
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