Long-Term Impact of an Educational Antimicrobial Stewardship Program on Hospital-Acquired Candidemia and Multidrug-Resistant Bloodstream Infections: A Quasi-Experimental Study of Interrupted Time-Series Analysis

Abstract

Background The global crisis of bacterial resistance urges the scientific community to implement intervention programs in healthcare facilities to promote an appropriate use of antibiotics. However, the clinical benefits or the impact on resistance of these interventions has not been definitively proved. Methods We designed a quasi-experimental intervention study with an interrupted time-series analysis. A multidisciplinary team conducted a multifaceted educational intervention in our tertiary-care hospital over a 5-year period. The main activity of the program consisted of peer-to-peer educational interviews between counselors and prescribers from all departments to reinforce the principles of the proper use of antibiotics. We assessed antibiotic consumption, incidence density of Candida and multidrug-resistant (MDR) bacteria bloodstream infections (BSIs) and their crude death rate per 1000 occupied bed days (OBDs). Results A quick and intense reduction in antibiotic consumption occurred 6 months after the implementation of the intervention (change in level, −216.8 defined daily doses per 1000 OBDs; 95% confidence interval, −347.5 to −86.1), and was sustained during subsequent years (average reduction, −19,9%). In addition, the increasing trend observed in the preintervention period for the incidence density of candidemia and MDR BSI (+0.018 cases per 1000 OBDs per quarter; 95% confidence interval, −.003 to .039) reverted toward a decreasing trend of −0.130 per quarter (change in slope, −0.029; −.051 to −.008), and so did the mortality rate (change in slope, −0.015; −.021 to −.008). Conclusions This education-based antimicrobial stewardship program was effective in decreasing the incidence and mortality rate of hospital-acquired candidemia and MDR BSI through sustained reduction in antibiotic use.

Persuasive antimicrobial stewardship intervention in the context of a KPC outbreak: a controlled interrupted time series analysis

“…Our study shows that this kind of intervention may have sustainable results even if the initial design and implementation occur in an outbreak setting. There are concerns that reduction in consumption of some particular classes of antibiotics can result in unintended increase in other classes with similar deleterious ecological effects, the so called "squeezing the balloon effect" [14,20,21]. In our study we also measured total consumption of antimicrobials and observed a significant decreasing trend in the intervened ward.…”

“…In this kind of setting usually several interventions are put in place to control the outbreak as rapidly as possible and because AMS effects in terms of resistance are expected on the long run it may be harder to convince healthcare providers of its benefit. Also there are reports that AMS interventions effects usually fade with time with few studies reporting results beyond 24 months [3,14] and the ones implemented during outbreak settings seem to be specially difficult to sustain once the outbreak is controlled [3]. Our study shows that this kind of intervention may have sustainable results even if the initial design and implementation occur in an outbreak setting.…”

“…Our intervention had no impact in patient mortality or readmission rates, however better indicators such as infection-related mortality would be useful to show that this intervention is safe. Molina et al [14] showed that a persuasive intervention can even decrease mortality in the long run but the follow-up time of our study is still too short to assess this. There was an increase in length of stay in the intervention period but this increase was noticed in both groups so it can not be attributed to the AMS intervention alone.…”

“…The main aim of AMS programs is to improve patient care and while reductions in antimicrobial use have been associated with better clinical outcomes, [13,14] this should not be assumed without direct evidence [3]. Our intervention had no impact in patient mortality or readmission rates, however better indicators such as infection-related mortality would be useful to show that this intervention is safe.…”

“…Some evidence, although less robust, also exists for the role of such strategies in reducing antimicrobial resistance [13]. However, robust evidence supporting different kinds of AMS interventions is still incomplete [14]. To fulfil this gap, in a pragmatic and realistic approach, the use of interrupted time series (ITS) analysis can be useful to evaluate complex interventions used in AMS programs [3,9,15].…”