title: Impact of antimicrobial resistance on health outcomes in the out-patient treatment of adult community-acquired pneumonia: a probability model.
abstract: Out-patient treatment of community-acquired pneumonia (CAP) is a major challenge in an era of increasing prevalence of antimicrobial resistance. However, data describing the clinical impact of such resistance are scarce. A probability model was developed to estimate the impact of antimicrobial resistance on clinical outcomes for adults with CAP, eligible for out-patient care. The model assumed patients would be evaluated at 48-72 h, with those failing to improve being either hospitalized or switched to a different antibiotic. Two strategies were considered: amoxicillin followed by erythromycin (amoxicillin/erythromycin) and erythromycin followed by levofloxacin (erythromycin/levofloxacin). Analyses were conducted based on susceptibility of the major pathogens in France and the UK. Primary model-generated outcome measures were the proportion of patients successfully treated with first-line therapy and the proportion of patients subsequently hospitalized. The model estimated that in France, the amoxicillin/erythromycin strategy would lead to 67.8% improving within 48-72 h and 12.7% subsequently being hospitalized, compared with 48.6% and 13.7% for erythromycin/levofloxacin. For the UK, first-line success and hospitalization rates were, respectively, 71.7% and 8.1% for amoxicillin/erythromycin, and 65.3% and 9.3% for erythromycin/levofloxacin. The model estimated that antimicrobial resistance was responsible for >40% of hospitalizations in France and 15% in the UK. These data suggest that in areas with substantially reduced levels of susceptibility, antimicrobial resistance may be a significant contributor to subsequent hospitalization in adults initially treated as out-patients for CAP. Choice of out-patient treatment strategy should consider local resistance rates in order to maximize the likelihood of early cure, thereby minimizing hospitalizations.
authors.affiliation: Department of Epidemiology and Biostatistics, Case Western Reserve University School of Medicine, and Center for Quality Improvement Research, Department of Veterans Affairs Medical Center, Cleveland, OH USA. mes12@po.cwru.edu
authors.forename: Mendel E
authors.initials: ME
authors.lastname: Singer
authors.forename: Ian
authors.initials: I
authors.lastname: Harding
authors.forename: Michael R
authors.initials: MR
authors.lastname: Jacobs
authors.forename: Dena H
authors.initials: DH
authors.lastname: Jaffe
mesh_terms: D000328:Adult; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D017714:Community-Acquired Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D005602:France / Q000453:epidemiology; D006192:Haemophilus Infections / Q000188:drug therapy / Q000453:epidemiology; D006193:Haemophilus influenzae / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D015233:Models, Statistical; D011008:Pneumococcal Infections / Q000188:drug therapy / Q000453:epidemiology; D011014:Pneumonia / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D011336:Probability; D013296:Streptococcus pneumoniae / Q000187:drug effects; D016896:Treatment Outcome; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D000890:Anti-Infective Agents