Assessing quality in pediatric surgery--the limited role of appendectomy as the optimal target

Background: Appendectomy is one of the highest volume procedures in children performed across a variety of hospital types in the U.S. potentially making it the ideal procedure to target when assessing hospital and surgeon quality. Though appendiceal perforation rate has been identified as a potential quality target reflecting primary care access, perforation rates have little association with hospital or surgeon quality. The utility and reliability of appendectomy as a target procedure to judge hospital quality based on outcomes beyond perforation rates are unknown.

Methods: Using the 2008 Nationwide Inpatient Sample, hospital pediatric appendectomy volumes were determined. Based on literature review, a variety of complication rate thresholds to identify hospital outlier status were determined using sample size calculations. The percent of U.S. hospitals that could exceed volume thresholds in order to be reliably compared was determined.

Results: Several complication rates of interest were identified ranging from mortality at 0.19% to a composite overall morbidity at 6.44%. Minimum hospital caseloads required to detect a doubling of complication rates included 127 cases for a composite overall morbidity, 276 cases for wound infection, 285 cases for negative appendectomy, 335 cases for intra-abdominal abscess, 438 cases for postoperative ileus, and 4,729 cases for mortality. Based on annual volumes, only 22% of hospitals met the minimum volume thresholds for a composite overall morbidity. In order to use other outcomes to assess quality, multiple year aggregate data are needed in order to generate volumes sufficient for comparison. Even with 5 year aggregate data less than 2% of hospitals could be compared based on mortality.

Conclusions: For the vast majority of complications very few hospitals accrue enough procedure specific volume with appendectomy to judge quality even with multiple years of data collection. In order to best assess hospital quality in children's surgery alternate targets beyond procedure specific traditional outcomes warrant exploration.