JUN 01, 2010
This study's authors report the use of cumulative sum (CUSUM) analysis to monitor phacoemulsification performance. A statistical tool that quantitatively scores performance outcomes, CUSUM has been used in manufacturing for quality control and to monitor the performance of surgery and other medical procedures but not to date in ophthalmology.
The authors conclude that CUSUM analysis is an objective, dynamic monitoring tool that can promptly detect adverse event and unacceptable outcome trends in cataract surgery. It is useful for busy physicians who supervise trainees, as well as surgeons undergoing training or those with experience who want to maintain their competency. The authors report its superiority over conventional trainee monitoring methods that may assess performance subjectively and based on quantity and not quality of surgery performed.
CUSUM analysis was applied to 80 phacoemulsification procedures performed by three ophthalmic trainees and one senior physician in Malaysia to track posterior capsular rupture and postoperative refracted vision worse than 6/12 among patients without pre-existing ocular comorbidity. Performance within acceptable standards has a negative score and shows a CUSUM chart that is flat or slopes downwards. Unacceptable performance has a positive score and an upward-sloping chart.
The CUSUM charts of the trainees demonstrated an initial upward trend followed by a flattening trend, which reflects learning curves for performing phacoemulsification. In contrast, the senior physician's chart showed a flat curve indicating an ongoing maintenance of competence.