Effect of Clinical Pharmacy Services on Appropriateness of Serum Digoxin Concentration Monitoring

The effects of four levels of clinical pharmacy services on increasing the appropriate ordering of serum digoxin concentration (SDC) determinations for cardiothoracic surgery patients were studied. During four equivalent four-month periods from 1983 to 1986, the pharmacist on the cardiothoracic surgery service provided four different levels of clinical services: no services (Period 1), participation in ward rounds only (Period 2), participation in ward rounds supplemented by the regular provision of inservice education programs (Period 3), and participation in ward rounds only (Period 4). Explicit criteria for the appropriate monitoring of digoxin therapy were developed from published criteria and an extensive literature review; all SDC determinations that did not meet one of these criteria were deemed inappropriate. All adult patients who received digoxin therapy were included in the study; data collected for each patient included the time and amount of the daily digoxin dose and the route of administration, the time at which blood was drawn for each SDC determination, and the assay results. Data were collected through a retrospective chart review for Period 1 and concurrently thereafter. The number of appropriate SDC determinations in Period 1 were compared with the total number of appropriate SDC determinations in Periods 2, 3, and 4; Periods 2 and 4 were compared with Period 3; and Period 2 was compared with Period 4. The costs avoided as the result of decreased numbers of SDC determinations ordered were calculated as the differences between the cost of inappropriate SDC determinations in Period 1 and the costs in Periods 2, 3, and 4.(ABSTRACT TRUNCATED AT 250 WORDS)