The Digitalis Investigation Group (DIG) clinical train randomized 6800 congestive heart failure patients (ejection fraction > or =45%) to a daily regimen of either digoxin or placebo. At 37 months average follow-up, patients in both groups had similar mortality. We determined the incremental costs associated with the use of digoxin in this high-risk population.
Hospitalizations and medical costs were compared by using a societal perspective. Hospitalizations were assigned Medicare DRG codes by using descriptive information from the clinical trial. Digoxin use was assigned a cost by using the 1998 average wholesale price as reported by Red Book. On average, there were fewer hospitalizations in digoxin-treated patients. These patients had lower heart failure yet higher non-heart failure hospitalization costs than placebo patients. Digoxin therapy was cost saving versus placebo in only 27% of 1000 bootstrap samples using Medicare costs (mean costs 12,648 dollars vs. 12,362 dollars) and in 44% of samples using commercial carrier costs (mean costs 17,400 dollars vs. 17,306 dollars). How ever, digoxin was cost saving in >50% of samples for several higher-risk patient subgroups.
The use of digoxin therapy versus placebo was associated with reduced hospitalizations. Moreover, the resulting cost-savings could cover the costs of this inexpensive therapy in selected subgroups of higher-risk patients. In the remainder, there is a modest cost associated with this therapy.