REVIEW STUDY: PREVALENCE OF ANTIMICROBIAL RESISTANCE PATTERNS AND THEIR IMPACT ON EMPIRICAL THERAPY

Abstract

Antimicrobial resistance (AMR) is a significant global burden and a substantial public health threat that requires immediate interventions. Surveillance data indicates that resistance rates are increasing worldwide. Inappropriate empirical antimicrobial therapy could lead to treatment failure and poor clinical outcomes when a pathogen bears resistance mechanisms. Empirical therapy with more extensive coverage might be necessary, but it comes at increased expense, toxicity, and adverse drug events. The absence of nationwide antibiotic susceptibility data to guide empirical therapy increases the likelihood of inappropriate therapy.

A six-month prospective cohort study was conducted at a tertiary university hospital in Southern Thailand. Adult patients (>18 years) who had positive blood or sterile site culture were enrolled. They were grouped based on empirical therapy (no AT) and appropriate empirical therapy (AT). The primary outcome was 30-day all-cause mortality. The sample size was calculated based on prevalence, and the compliance of all patients who met inclusion criteria was assessed at initially included patients within each group. The secondary outcomes included hospital length of stay, time to receive appropriate therapy, and factors impacting treatment changes. The statistics were analyzed using a Chi-square and Mann-Whitney tests.

In total, 482 patients were included in the study, of whom 415 (72.7%) received empirical irrelevant antibiotics. AT group (78.4%) more often developed fever than no AT (65.4%). These factors were respective crude odds ratios of 1.676 and 2.036. The isolated pathogens of blood or sterile site cultures were tested against either first-line or second-line antibiotics. Consequently, 343 (82.6%) organisms were resistant to first-line antibiotics. Of these, 234 (68.2%) with antimicrobial resistance patterns were not targeted by empirical therapy, leading to post-test treatments without subsequent improvement. AT could improve microbiological outcomes, as the organism prevalence and resistance profile were altered. Patients with no AT might require an increased change in treatment, additional tests, and prolonged hospital length of stay.