Evaluation of a quality assurance technique for a pharmacokinetic dosing service

A quality assurance (QA) technique that measured process and outcome was tested on a clinical pharmacokinetic dosing service (CPDS). The process measurement criteria evaluated the CPDS pharmacists' ability to maintain serum aminoglycoside levels within the desired range (peak 6-10 micrograms/ml, trough less than 2.0 micrograms/ml). The outcome measurement criteria evaluated the patients' clinical response to the aminoglycoside therapy based on changes in the patients' temperature, white blood cell count, bacterial cultures, and other variables. The process evaluation found that in a majority of the patients (80 percent), the CPDS pharmacist was performing at a level exceeding the process criteria. The outcome evaluation found that in a majority of the patients (76 percent), the therapeutic outcome criteria were not met. Statistical analysis using Spearman's Rho was not able to relate process and outcome measures significantly (p greater than 0.05). The patient outcome criteria may not have accurately measured patient outcome because of inflexibility, not measuring other patient variables, and the lack of a subjective component. Validation of the QA technique was not possible in this study.