Meta-analysis of research on the effect of clinical pharmacokinetics services on therapeutic drug monitoring.

A meta-analysis of 27 published and unpublished studies of the impact of clinical pharmacokinetics services on patients' serum drug concentrations, the appropriate collection of blood samples, and the appropriate use of assay results was conducted. An individual study's effect size (ES) was determined by subtracting probits or by calculating the Bayesian estimate of pi derived from the percentages observed in the experimental and control groups. Weights based on an individual study's sample size were used to estimate the overall ES. Patients monitored by clinical pharmacokinetics services were significantly more likely to have serum drug concentrations within an acceptable therapeutic range than were patients who were not monitored. When each of the monitoring parameters was investigated individually, monitored patients were more likely to have therapeutic peak (ES = 0.51, 95% confidence interval = -0.34 to 1.36) and trough (ES = 1.15, 95% CI = -0.37 to 2.68) serum drug concentrations, to be within therapeutic range (ES = 0.91, 95% CI = 0.19 to 1.63), and to have fewer toxic peak (ES = 0.06, 95% CI = -0.53 to 0.65) and trough (ES = 0.96, 95% CI = 0.12 to 1.82) serum drug concentrations. Clinical pharmacokinetics services were also more likely to have collected blood samples appropriately (ES = 0.87, 95% CI = -0.25 to 2.00) and to have used assay results appropriately (ES = 1.21, 95% CI = -0.46 to 2.88). Clinical pharmacokinetics services appeared to have a significant influence on the proportion of patients with desirable serum drug concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)