The Certification Study Guide (6th edition) emphasizes that process performance indicators directly linked to evidence-based practices are the most effective measures for reducing healthcare-associated infections such as CLABSI. Among the options listed, 100% compliance with the central line insertion bundle is the only indicator consistently demonstrated to reduce CLABSI rates.

Insertion bundles are standardized sets of practices that include proper hand hygiene, maximal sterile barrier precautions, use of appropriate skin antisepsis (preferably chlorhexidine), optimal catheter site selection, and daily review of line necessity. The study guide explains that reliable execution of these bundled practices addresses the most common routes of microbial entry at the time of line placement, which is a critical risk period for bloodstream infection.

The other options do not represent valid improvement indicators. Total parenteral nutrition is a known risk factor for CLABSI, not a prevention strategy. Use of povidone-iodine ointment at insertion sites is not recommended and may increase infection risk. Routine guidewire exchanges are discouraged because they do not reduce infection risk and may increase contamination.

Therefore, measuring and achieving full compliance with the insertion bundle is a meaningful, actionable performance indicator that aligns with CBIC exam expectations and infection prevention best practices.