Use of a data warehouse to monitor simvastatin tablet splitting.

A data warehouse was used to examine the LDL levels for patients who were switched from whole to half tablets of simvastatin. The LDL levels were available both pre and post conversion. 7,321 patients were switched and the LDL levels for these patients were tracked. 1,408 patients had a slight increase in LDL (less than 15% above baseline). Those patients whose LDL increased by greater than 15%, and was above 120 mg/dl, were switched back to whole tablets.