My colleague and I used a speialized HESI test that reflected the content that we were teaching. The questions had established validity and reliability which made them good tools. We chose questions from a pool of items that matched up with our learning objectives (in our case it was ECG interpretation and response) and created a 20 item exam for students to take after simulation experiences over several weeks for the treatment group in our study, and following classroom instruction without simulation in our control group. The study was published in Clinical Simulation in Nursing journal if you are interested (full reference below).
Brown, D., & Chronister, C., (2009). The effect of simulation learning on critical thinking and self-confidence when incorporated into an electrocardiogram nursing course, Clinical Simulation in Nursing, 5, e45-e52.