Economic and outcome issues for therapeutic drug monitoring in medicine.
Outcome and economic studies pertaining to the use of therapeutic drug monitoring (TDM) are summarized. The studies were classified by a 2 x 2 matrix comprised of process, outcome, system-related variables, and patient-centered variables. Two hundred forty-seven studies conducted from 1974 to 1994, culled from eight summary sources, were reviewed. Almost 75% of the studies reported system-related, not patient-centered, measures for assessing the value of TDM; nearly the same percentage evaluated processes as opposed to outcome measures. Studies comparing TDM to non-TDM populations generally showed that TDM as an intervention reduced the rate of undesirable system-related variables by 50% and increased the rate of desirable system-related variables by 100%. For patient-centered variables, TDM was less dramatic, decreasing the rate of undesirable variables by 15% to 50%. Only 8% of the studies examined economic variables. TDM-influenced changes in process variables resulted in a projected mean annual savings of $37,000. The few studies available of cost-benefit analysis focused on aminoglycosides and showed that TDM yielded a range from 4:1 to 52:1 in benefit-to-cost ratio. Most studies have limitations that include small sample size, short study periods to predict long-term outcomes, no long-term follow-up, and designs for noncontrolled study.
National Education and Research Center for Outcomes Assessment in Healthcare, Bouve College of Pharmacy and Health Sciences, Northeastern University, Boston, Massachusetts 02115, USA.
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Schumacher
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JT
Barr
D016903:Drug Monitoring / Q000191:economics*; D017850:Economics, Pharmaceutical; D006801:Humans; D017063:Outcome Assessment, Health Care; D014481:United States