Under the Performance and Process Improvement domain, NAHQ emphasizes selecting the correct analytical tool based on the purpose of analysis. The goal in this scenario is to prioritize causes of surgical delays across multiple categories and time periods.

A Pareto chart is specifically designed to rank causes by frequency and identify the “vital few” contributors responsible for the majority of the problem. This aligns with the Pareto principle (80/20 rule), which is a core concept tested on the CPHQ exam. Once the highest contributors are identified, an action plan can be developed to address those priority areas.

An Ishikawa diagram (Option A) is more appropriate for root cause analysis after a priority issue has already been identified. Histograms (Option B) display distribution, not prioritization by category. Control charts (Option C) are used to monitor process stability over time, not to prioritize causes. Therefore, Option D represents the correct and NAHQ-aligned next step.