Azar‐Cavanagh 2007.

Methods	Study design: Interrupted Time‐Series Study
Participants	USA. Healthcare workers handling needles and thus with potential exposure to blood borne pathogens. Number studied: 11,161 healthcare workers for the pre‐intervention period (18 months) and 12,851 healthcare workers for the post‐intervention period (18 months).
Interventions	Introduction of an intravenous catheter stylet with a safety engineered feature (a retractable protection shield). The mechanism has to be activated by the worker. Suture needles were not replaced by safety engineered needles and were thus used as control group.
Outcomes	Number of percutaneous injuries per 1000 healthcare workers.
Notes	Pre‐intervention rate (PI per 1000 health workers) IV catheter needle (2.5; 2.3, 2.5 for each six‐month period respectively). Total data points (n = 6).