Association of Patient Belief About Success of Antibiotics for Appendicitis and Outcomes

Abstract

ImportanceA patient’s belief in the likely success of a treatment may influence outcomes, but this has been understudied in surgical trials.ObjectiveTo examine the association between patients’ baseline beliefs about the likelihood of treatment success with outcomes of antibiotics for appendicitis in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial.Design, Setting, and ParticipantsThis was a secondary analysis of the CODA randomized clinical trial. Participants from 25 US medical centers were enrolled between May 3, 2016, and February 5, 2020. Included in the analysis were participants with appendicitis who were randomly assigned to receive antibiotics in the CODA trial. After informed consent but before randomization, participants who were assigned to receive antibiotics responded to a baseline survey including a question about how successful they believed antibiotics could be in treating their appendicitis.InterventionsParticipants were categorized based on baseline survey responses into 1 of 3 belief groups: unsuccessful/unsure, intermediate, and completely successful.Main Outcomes and MeasuresThree outcomes were assigned at 30 days: (1) appendectomy, (2) high decisional regret or dissatisfaction with treatment, and (3) persistent signs and symptoms (abdominal pain, tenderness, fever, or chills). Outcomes were compared across groups using adjusted risk differences (aRDs), with propensity score adjustment for sociodemographic and clinical factors.ResultsOf the 776 study participants who were assigned antibiotic treatment in CODA, a total of 425 (mean [SD] age, 38.5 [13.6] years; 277 male [65%]) completed the baseline belief survey before knowing their treatment assignment. Baseline beliefs were as follows: 22% of participants (92 of 415) had an unsuccessful/unsure response, 51% (212 of 415) had an intermediate response, and 27% (111 of 415) had a completely successful response. Compared with the unsuccessful/unsure group, those who believed antibiotics could be completely successful had a 13–percentage point lower risk of appendectomy (aRD, −13.49; 95% CI, −24.57 to −2.40). The aRD between those with intermediate vs unsuccessful/unsure beliefs was −5.68 (95% CI, −16.57 to 5.20). Compared with the unsuccessful/unsure group, those with intermediate beliefs had a lower risk of persistent signs and symptoms (aRD, −15.72; 95% CI, −29.71 to −1.72), with directionally similar results for the completely successful group (aRD, −15.14; 95% CI, −30.56 to 0.28).Conclusions and RelevancePositive patient beliefs about the likely success of antibiotics for appendicitis were associated with a lower risk of appendectomy and with resolution of signs and symptoms by 30 days. Pathways relating beliefs to outcomes and the potential modifiability of beliefs to improve outcomes merit further investigation.Trial RegistrationClinicalTrials.gov Identifier: NCT02800785

Patient Beliefs About Antibiotics for Appendicitis and Outcomes

“…First, we note that appendicolith was more common in the unsuccessful/unsure group (34 [37%]) than in the completely successful group (27 [24%]) or intermediate group (54 [25%]) . Another study showed that appendicolith was a risk factor for failure of antibiotics in appendicitis treatment, and this was also confirmed by the CODA randomized clinical trial, which found that appendicolith was associated with a nearly 2-fold increased risk of undergoing appendectomy within 30 days of initiating antibiotics .…”

“…In Figure 2 in the article by the Writing Group for the CODA Collaborative, in the 95% CI of risk difference in the completely successful row, the data of upper limits are different from the description in the Results section and seem to be missing minus signs. This is also the case for 95% CIs in the unadjusted risk difference column in Figure 3 in the article.…”

“…To the Editor We read with great interest the article by the Writing Group for the CODA Collaborative that studied whether patient beliefs about success of antibiotics for appendicitis were associated with outcomes . We appreciate the authors’ effort in exploring such a novel topic that revealed positive patient beliefs were associated with improved outcomes regarding success of antibiotics for appendicitis.…”

Patient Beliefs About Antibiotics for Appendicitis and Outcomes—Reply

“…In Reply We appreciate the comments from Yan and Sha regarding our recently published article . At the time the CODA trial was being conducted, the relationship between appendicoliths and appendectomy after antibiotics in adults was not known.…”

“…Lastly, regarding the question of appendicolith and appendectomy, because of its importance, we adjusted for appendicolith status in our adjusted risk differences (see Figure 2 in our article). We found that differences between the completely successful and unsuccessful/unsure groups are similar before (risk difference, −14.08; 95% CI, −25.46 to −2.70) and after (adjusted risk difference, −13.49; 95% CI, −24.57 to −2.40) adjustment.…”