Evaluation of beta-lactam therapeutic drug monitoring among US health systems with postgraduate year 2 infectious diseases pharmacy residency programs

Purpose: While some guidelines recognize the need for beta-lactam therapeutic drug monitoring (TDM), there is still a paucity of data regarding the prevalence of and barriers to performing beta-lactam TDM in the United States. We sought to estimate the prevalence of beta-lactam TDM, describe monitoring practices, and identify actual and perceived barriers to implementation among health systems in the US. Methods: A multicenter, cross-sectional, 40-item electronic survey was distributed to all postgraduate year 2 (PGY2) infectious diseases (ID) pharmacy residency program directors (RPDs) listed in the American Society of Health-System Pharmacists pharmacy residency directory. The primary outcome was the percentage of institutions with established beta-lactam TDM. Secondary outcomes included assessing beta-lactam TDM methods and identifying potential barriers to implementation. Results: The survey was distributed to 126 PGY2 ID RPDs, with a response rate of 31.7% (40 of 126). Only 8% of respondents (3 of 39) performed beta-lactam TDM. Patient populations, therapeutic targets, and frequency and timing of obtaining repeat beta-lactam concentration measurements varied among institutions. The greatest barrier to implementation was lack of access to testing with a rapid turnaround time. Institutions were unlikely to implement beta-lactam TDM within the next year but were significantly more inclined to do so within 5 years (P < 0.001). Conclusion: beta-lactam TDM was infrequently performed at the surveyed US health systems. Lack of access to serum concentration testing with rapid turnaround and lack of US-specific guidelines appear to be considerable barriers to implementing beta-lactam TDM. Among institutions that have implemented beta-lactam TDM, there is considerable variation in monitoring approaches.