Quasi-experimental study over 140 months, 5 states, six specialty settings (3 intensive care units (ICU), and one each of medical ICU, surgical ICU, and Long Term Acute Care -LTAC) comparing CLA-BSI rates associated with positive (6,649 catheter-days) or negative (17,810 catheter-days) IV needleless connectors. There were a total of 24,459 pre-zero fluid displacement catheter-days over 70 months compared to 25,621 total post zero displacement connector catheter-days over 70 months. Paired t-tests were used to examine differences between catheter-days and CLA-BSI rates before and after zero fluid displacement connector adoption. Statistical significance was assessed using an alpha level of 0.05.