Pharmaceutical guideline compliance and its impact on costs and effectiveness: Case studies of orders based on vancomycin use and intravenous to oral switch antimicrobial guidelines at The Ohio State University Medical Center

The goals of practice guidelines are to improve quality and reduce cost. However, evaluation of guidelines relative to goals has been limited. A paucity of studies on locally developed guidelines is found in the literature. The purpose of this study was to examine the effect of guidelines on outcomes. The guidelines studied were Converting From Intravenous to Oral Antimicrobial Therapy and Criteria for Use of Vancomycin. The guidelines were examined independently and the study design was a two group, observational, cohort design. Groups were defined based on treatment compliant with guideline recommendations versus not compliant. The target populations were patients with drug orders for medications covered by the guidelines. Data were collected via written baseline and follow-up survey, chart review and hospital database. The first three objectives were to evaluate the effect of compliance on economic, clinical and health status outcomes. The final objective was to determine if order compliance was cost effective relative to non-compliance. For the vancomycin guideline, the study determined compliance did not have statistically significant effect on economic or health status outcomes. However, the results were significant since order compliance produced clinical outcomes that were better than non-compliant with the guideline. Specifically, mortality was lower and antimicrobial success rates were higher for the compliant cohort. Despite improved clinical effect, the study did not find evidence that following guideline recommendations for the vancomycin guideline was more cost effective. Similarly, for the iv to po guideline, statistically significant effects of order compliance was not found for economic, clinical, health status outcomes or on cost effectiveness analysis. However, the non-compliant cohort had higher total hospital costs and lower lengths of stay compared to the compliant cohort. This result indicates that physicians were more likely to minimize iv to po switch due to potential drug failure error (Type I error) and instead keep patients on iv drug therapy longer even though the switch to po may have been indicated by the guideline (Type II error). Evaluation protocols for guidelines should be examined and specified based on the goals of the guidelines prior to implementation.