Mandatory laboratory consultation: How one hospital's program reduced overuse of cardiac tests

We retrospectively analyzed test use patterns during a 4-year period before and after institution of a mandatory laboratory approval program for lactate dehydrogenase isoenzyme analysis. In the first month after institution of the program, requests for lactate dehydrogenase isoenzymes declined from about 2,000 per month to 7 per month (greater than 99% decrease) and remained stable for 2 years. The decrease in lactate dehydrogenase isoenzyme requests did not result in any significant change in requests for creatine kinase or creatine kinase MB isoenzyme, and total lactase dehydrogenase requests (relative to creatine kinase requests) were reduced. Of the remaining lactate dehydrogenase isoenzyme tests that were performed, most were normal or nondiagnostic.