A clinical quality control study systematically monitors healthcare processes and outcomes to ensure that care is delivered safely, effectively, and consistently. In surgical practice, these studies often focus on tracking complication rates, adherence to protocols, and procedural performance.

CUSUM analysis is particularly well suited for clinical quality control studies because it:

• Detects small but consistent changes in performance over time
• Identifies early trends toward improvement or deterioration
• Allows for real-time surveillance rather than delayed audit cycles
• Supports continuous quality improvement and training evaluation

A quality control study using CUSUM for ICP monitor placement might include:

• Objective: Monitor complication rates and learning curves in residents and attending neurosurgeons
• Population: All patients undergoing ICP monitor placement over 12 months
• Outcome measure: Binary (0 = success, 1 = complication)
• Reference value (k): Derived from institutional or published data (e.g., 0.10)
• Alert threshold: Empirically set (e.g., 2.5) to flag deviation from acceptable performance
• Stratification: By supervision level, case complexity, or operator experience

• CUSUM charts are generated for each operator or time block.
• Performance trends are reviewed monthly by a clinical governance team.
• Breaches of the threshold trigger a focused case review or supervision adjustment.
• Sustained improvements are noted and used for educational feedback or procedural guideline validation.

Clinical quality control studies using CUSUM:

• Move beyond static auditing by enabling dynamic quality surveillance
• Create a non-punitive feedback environment for surgeons in training
• Align individual performance monitoring with institutional safety goals
• Serve as publishable data for departmental research, training outcomes, or accreditation

By embedding CUSUM into structured quality control studies, institutions foster a culture of transparency, accountability, and continuous improvement.