Antibiotic Stewardship: Metrics, Doctors’ Priorities Differ

Veronica Hackethal, MD

October 03, 2014

Clinicians consider patient outcomes to be more important than costs, but these outcomes are rarely measured in antibiotic stewardship program (ASP) metrics, according to a survey study published in a supplement to the October issue of Clinical Infectious Diseases.

The study is one of several about ASPs published in a special journal supplement dedicated to these programs.

"The [Infectious Disease Society of America/Society of Healthcare Epidemiology of America (IDSA/SHEA)] guidelines provide recommendations for developing an ASP with the goal of improving quality of care and outcomes. Unfortunately, 5 years after publication of the guidelines, patient outcomes were still not widely assessed in this group of ASPs," the authors write.

"In light of a potential requirement for ASPs and to advance the programs, ASP personnel must increase focus on patient outcomes and unintended consequences of antimicrobial use."

In March 2012, the authors emailed a 55-question online survey to 94 physicians or pharmacists in acute care hospitals in the United States to identify which outcomes they considered most important compared with those usually measured in ASP metrics. They based outcomes or metrics included in the survey on IDSA/SHEA ASP guidelines. The authors sent surveys to one provider per institution, selected from those who had contact with Cubist Pharmaceuticals and who either had existing ASPs or had plans for establishing one.

Response relied on voluntary effort, and not all surveys were completed, which could have limited the study. The researchers selected hospitals from those with contacts with Cubist Pharmaceuticals, the sponsor of the study, which could have introduced selection bias. Finally, the small sample size limits the study.

The overall response rate was 51%, with respondents from 29 states and 48 institutions. Among those with ASPs (41 institutions), there was a disconnect between variables that respondents considered most important and those collected as metrics.

Antimicrobial use and cost were the most commonly collected metrics (both at 73%), even though respondents considered the most important variables to be appropriate antimicrobial use (56% vs 51%), infection-related mortality rate (34% vs 7%), and antibiotic-associated length of stay (22% vs 12%). Only 10% of respondents indicated antimicrobial cost as most important.

Infectious disease physicians considered infection-related mortality rate to be the most important variable (37%), whereas hospital administrators and pharmacy directors considered antibiotic cost as most important (41.5% and 56%, respectively).

There is general agreement, according to Ronald Polk, PharmD, emeritus professor at the Virginia Commonwealth University in Richmond, that all of the metrics examined in this study should be collected, but clinical outcomes are "far more important" than costs and antimicrobial drug use and it is "very difficult" to convincingly link clinical outcomes to ASP interventions.

"Since ASPs are still in their infancy in terms of developing appropriate study design and statistical analysis to causally link an ASP intervention to a change in clinical outcomes, it is no wonder that ASPs focus on the 'easy' metrics (money saved), especially since that is most often the metric of interest to the administrators who are paying for the program," commented Dr Polk, who was not involved in the study.

"The strength of the study is that it attempts to quantify the disconnect that many people have previously emphasized [in prior publications]: that clinical outcomes are more important than economic and process measures," Dr Polk added.

"This study emphasizes that ASP personnel are aware that improved clinical outcomes should be one of the most important areas of emphasis of ASP, but these data are difficult to obtain," Dr Polk emphasized. "Consequently, the 'low-lying fruit' of lower costs is often the outcome that is collected first. By implication, this study also emphasizes what has been previously identified by many: the importance of future research convincingly linking ASP interventions to improved clinical outcomes."

The study was funded by Cubist Pharmaceuticals, and editorial support was provided by ApotheCom ScopeMedical. Dr Polk and three coauthors report various financial relationships with Cubist Pharmaceuticals.

Clin Infect Dis. 2014:59:S108-S111. Full text


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