By Richard R. Watkins, MD, MS, FACP, FIDSA

Associate Professor of Internal Medicine, Northeast Ohio Medical University, Rootstown, OH; Division of Infectious Diseases, Cleveland Clinic Akron General, Akron, OH

Dr. Watkins reports no financial relationships relevant to this field of study.

SYNOPSIS: A retrospective cohort study that used national insurance claims data revealed patients with acute appendicitis who were treated nonsurgically experienced higher rates of complications and higher overall care costs.

SOURCE: Sceats LA, et al. Nonoperative management of uncomplicated appendicitis among privately insured patients. JAMA Surg 2018; doi: 10.1001/jamasurg.2018.4282. [Epub ahead of print].

The management of acute appendicitis without appendectomy has generated considerable interest among clinicians and patients in recent years. Several clinical trials have shown similar outcomes with appendectomy and nonsurgical management (i.e., antibiotics). However, deciding which patients should be managed without surgery has been challenging, and long-term data are scarce. Sceats et al aimed to clarify these issues by comparing outcomes for patients with acute appendicitis who underwent appendectomy to those who received nonsurgical management. The study was a retrospective cohort analysis that used information from a claims database of 40-50 million privately insured patients, mainly with large employer-sponsored health plans. Researchers included patients who received an admission diagnosis of acute appendicitis between Jan. 1, 2008, and Dec. 31, 2014. Patients were divided into two groups: those who underwent appendectomy based on the presence of procedure codes and those who received nonsurgical management.

The primary outcomes were rates of short-term (< 30 days) complications (i.e., ED visits, all-cause readmissions, appendicitis-associated readmissions, occurrence of abdominal abscess, and Clostridium difficile infection), and long-term (> 30 days) complications (i.e., readmission for small bowel obstruction, incisional hernia, and diagnosis of appendiceal cancer).

The researchers conducted a post hoc analysis on the nonsurgical group to evaluate the rate of management failure and the rate of appendicitis recurrence. Instead of using propensity score matching to balance the two groups, the authors used coarsened exact matching (CEM) because of a presumed bias in patients selected for nonsurgical management. This technique is based on forecasting after pruning observations such that the covariate distributions between the two groups improve in the data that remain.

Researchers identified 58,329 patients with acute appendicitis during the study period, of whom 55,709 underwent appendectomy and 2,620 received nonsurgical management. There were significant differences between the appendectomy and nonsurgical groups in terms of age (31.8 years vs. 34.2 years, respectively; P < 0.001) and the grouped Charlson comorbidity index (P < 0.001). Regarding short-term complications, patients who underwent nonsurgical management experienced significantly higher all-cause readmissions and appendicitis-associated readmissions (P < 0.001). Moreover, patients who received nonsurgical management were significantly more likely to develop an abdominal abscess than those who underwent appendectomy (2.3% vs. 1.3%, respectively; adjusted odds ratio [aOR], 1.42; 95% confidence interval [CI], 1.05-1.92). The results indicated no significant differences in the rates of ED visits or C. difficile infection.

Among long-term complications, those patients managed nonsurgically showed higher rates of appendiceal cancer compared to those who underwent appendectomy (aOR, 4.07; 95% CI, 2.56-6.49). There were no significant differences in the rates of admission for small bowel obstruction or incisional hernias. The length of stay was slightly longer in the nonsurgical group (1.7 days vs. 1.6 days), and these patients also logged more follow-up visits for appendicitis in the year following hospital discharge compared to those who underwent appendectomy (1.6 visits vs. 0.3 visits; P < 0.001). The nonsurgical group paid lower mean costs for index hospitalization. However, when the total cost of care associated with appendicitis was evaluated, nonsurgical management was more expensive ($14,934 vs. $14,186). The overall failure rate of nonsurgical management was 3.9%, and the median time from the initial diagnosis to management failure or recurrence was 42 days (range, 8-125 days).

COMMENTARY

This is an interesting and important study because it informs clinicians about managing acute appendicitis nonsurgically in a real-world setting (i.e., outside of a clinical trial). Of the 4.5% of patients managed nonsurgically, only 3.9% required an appendectomy during a mean follow up of 3.2 years. This is in contrast with results from randomized clinical trials, in which such rates were approximately 27%. The reason for this discrepancy is uncertain and might be a result of the patient populations studied, although an alternative explanation is that patients in clinical trials are monitored more carefully. Readmission rates, office visits, and complications (including abscess formation and appendiceal cancer) were lower in the operative group. The authors of a recent randomized clinical trial found a high rate of appendiceal cancer in patients treated nonsurgically for peri-appendicular abscess.1

Although the cost of the initial hospitalization for acute appendicitis was lower in the nonsurgical group, this benefit was more than offset by the costs that came after, including more office and ED visits. The higher rates of complications also led directly to increased costs, which were 5.5% greater in the nonsurgical group. Moreover, the time out of work that the nonsurgical patients experienced because of their additional visits was an indirect cost that was not factored into the economic analysis.

There were a few limitations to the study. First, the cohorts were significantly different in terms of age and Charlson comorbidity index. Second, the retrospective design makes the presence of unmeasured confounding variables a possibility. Third, there also may have been selection bias in favor of nonsurgical management because this approach often is used when patients are deemed poor surgical candidates. The authors attempted to account for this possibility using the CEM algorithm and multivariate analysis.

Many, if not most, patients would choose to avoid appendectomy if they were told there was a reasonable chance of cure by nonsurgical management. It does them a disservice if the best available evidence suggests otherwise. Thus, the study by Sceats et al should be taken into account by clinicians (both surgeons and non-surgeons) during conversations with patients who have acute appendicitis about their expectations and possible outcomes.

REFERENCE

  1. Mällinen J, et al. Risk of appendiceal neoplasm in periappendicular abscess in patients treated with interval appendectomy vs follow-up with magnetic resonance imaging: 1-year outcomes of the peri-appendicitis acuta randomized clinical trial. JAMA Surg 2018; doi: 10.1001/jamasurg.2018.4373.