Evaluating the appropriateness of antimicrobial treatment in hospitalized patients: a comparison of three methods

Approximately 20-50% of antimicrobial therapy in hospitalized patients is considered inappropriate, which may be associated with increased morbidity and mortality. The best method for evaluation of appropriateness is not well defined.

To evaluate the rate of appropriate antimicrobial therapy in a secondary hospital using three different methods, and determine the rate of agreement between the different methods.

A point prevalence study included all adult hospitalized patients receiving systemic antimicrobial therapy during 2016, screened on a single day. Clinical, laboratory and therapeutic data were collected from patient files, and appropriateness was rated with a qualitative evaluation by expert opinion. In addition, a quantitative evaluation was performed according to 11 quality indicators (QIs) rated for each patient. A strict definition of appropriateness was fulfilled if six essential QIs were met, and a lenient definition was fulfilled if at least five QIs were met. Agreement between methods was analysed using kappa statistic.

Among 106 patients included, rates of appropriateness of antimicrobial therapy ranged from 20% to 75%, depending on the method of evaluation. Very low agreement was found between the strict definition and expert opinion (kappa=0.068), and medium agreement was found between the lenient definition and expert opinion (kappa=0.45).

Rates of appropriateness of antimicrobial therapy varied between evaluation methods, with low to moderate agreement between the different methods.