Figure 1

Changes in laboratory test ordering. Data is broken down into high frequency tests (core laboratory chemistry and hematology testing excluding CBC with differential), CBC with differential, erythrocyte sedimentation rate (ESR), and restricted send-out testing with effects on (A) frequency of ordering (adjusted for patient days) and (B) average annual savings. The pre-intervention period was two years leading up to interventions (changes in ordering frequency options; institution of restricted send-out testing) in July 2012. The post-intervention period is two years following that into July 2014. *P < 0.005, **P < 0.001.