Patient beliefs associated with successful antibiotic treatment of appendicitis

Patients' beliefs about treatment success may be associated with outcomes of antibiotic treatment for appendicitis, a recent study found.

Researchers performed a secondary analysis of the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial to examine the association between patients' baseline beliefs about the likelihood of antibiotic treatment success for appendicitis and treatment outcomes. Patients from CODA were included in the current analysis if they had been randomly assigned to receive antibiotics for appendicitis and had responded to a baseline survey before they were aware of their treatment assignment. They were categorized into one of three belief groups about the potential success of antibiotic treatment according to survey responses: unsuccessful/unsure, intermediate, and completely successful. Main outcomes at 30 days were appendectomy, high decisional regret or dissatisfaction with treatment, and persistent signs and symptoms (abdominal pain, tenderness, fever, or chills). Adjusted risk differences (aRDs) were used to compare outcomes across groups, with propensity score adjustment for sociodemographic and clinical factors. The study results were published Oct. 5 by JAMA Surgery.

Seven hundred seventy-six patients were assigned to antibiotic treatment, and of these, 425 completed the baseline survey before they learned their treatment assignment. Mean age was 38.5 years, and 65% were men. Twenty-two percent said they believed treatment would be unsuccessful or were unsure, 51% had an intermediate response, and 27% said they believed treatment could be completely successful. Patients who believed antibiotics could be completely successful had a lower risk of appendectomy than those who believed they would be unsuccessful or were unsure (aRD, −13.49 percentage points; 95% CI, −24.57 to −2.40 percentage points). For those with intermediate beliefs, the aRD versus those with unsuccessful/unsure beliefs was −5.68 percentage points (95% CI, −16.57 to 5.20 percentage points). Compared with the unsuccessful/unsure group, risk for persistent signs and symptoms was lower in those with intermediate beliefs (aRD, −15.72 percentage points; 95% CI, −29.71 to −1.72 percentage points). For those who believed antibiotics could be completely successful, the results were directionally similar, but the CI included 0 after adjustment (aRD, −15.14 percentage points; 95% CI, −30.56 to 0.28 percentage points). High decisional regret or dissatisfaction was reported by 19% of the unsuccessful/unsure belief group, 18% of the intermediate belief group, and 13% of the completely successful belief group.

The study was limited because it was a secondary analysis of a clinical trial involving patients who consented to randomization and because the survey question regarding beliefs was measured on a nonstandard scale, among other factors, the authors noted. Their results suggest that it is important to understand patients' beliefs about treatment success for appendicitis, they said. “This information might be expected to improve shared decision-making, even as we acknowledge that beliefs may influence outcomes in ways not yet fully understood,” the authors wrote. “The pathways relating beliefs to outcomes, the potential modifiability of beliefs to improve outcomes, and the interplay of patient, caregiver, and clinician beliefs are important areas for further investigation.”

An accompanying invited commentary stressed that the study does not prove causation and that more rigorous study examining multiple other variables is required before such findings could begin to be considered actionable.

“While the authors should be congratulated for generating information that suggests there ‘might be something here,’ the hard work needed to support mechanistic plausibility to this claim, as they acknowledge, remains to be produced,” the commentary author wrote. “Unless we insist on complementary biology-level measurements and hard mechanistic-based evidence to support our clinical observations, it seems we are no better than homeopathic claims that declare ‘if you think you are better, then you are better.’”