The Study phase of the PDSA (Plan-Do-Study-Act) cycle involves analyzing data from the Do phase to evaluate the intervention’s impact and inform next steps.

Option A (Radar chart): Radar charts compare multiple variables, not suited for analyzing test results.

Option B (Control chart): This is the correct answer. The NAHQ CPHQ study guide states, “In the Study phase of PDSA, control charts analyze data to assess whether the intervention stabilized or improved the process” (Domain 4). They show variation and trends post-intervention.

Option C (Brainstorming): Brainstorming generates ideas, relevant in the Plan phase, not Study.

Option D (Affinity diagram): Affinity diagrams organize ideas, not analyze test data.

CPHQ Objective Reference: Domain 4: Performance and Process Improvement, Objective 4.3, “Apply PDSA methodology,” includes control charts in the Study phase. The NAHQ study guide notes, “Control charts evaluate intervention outcomes in PDSA” (Domain 4).

Rationale: Control charts analyze data in the Study phase, aligning with CPHQ’s improvement principles.