Measuring antimicrobial use in hospitalized patients: a systematic review of available measures applicable to paediatrics.

OBJECTIVES The optimal measure to use for surveillance of antimicrobial usage in hospital settings, especially when including paediatric populations, is unknown. This systematic review of literature aims to list, define and compare existing measures of antimicrobial use that have been applied in settings that included paediatric inpatients, to complement surveillance of resistance. METHODS We identified cohort studies and repeated point-prevalence studies presenting data on antimicrobial use in populations of inpatients or validations/comparisons of antimicrobial measures through a systematic search of literature using MEDLINE, EMBASE, CINAHL and LILACS (1975-2011) and citation tracking. Study populations needed to include hospitalized paediatric patients. Two reviewers independently extracted data on study characteristics and results. RESULTS Overall, 3878 records were screened and 79 studies met selection criteria. Twenty-six distinct measures were found, the most frequently used being defined daily doses (DDD)/patient-days and exposed patients/patients. Only two studies compared different measures quantitatively, showing (i) a positive correlation between proportion of exposed patients and antimicrobial-days/patient-days and (ii) a strong correlation between doses/patient-days and agent-days/patient-days (r = 0.98), with doses/patient-days correlating more with resistance rates (r = 0.80 versus 0.55). CONCLUSIONS The measure of antimicrobial use that best predicts antimicrobial resistance prevalence and rates, for surveillance purposes, has still not been identified; additional evidence on this topic is a necessity.