Background

Examination of at least 12 lymph nodes (LNs) in the staging of colon cancer (CC) was recommended by the National Comprehensive Cancer Network in 2000; however, rates of an adequate examination remain low. This study compares the impact of the hospital contextual variance against that of the operating surgeon on delivery of an adequate LN examination.

Study design

Retrospective analysis of California Cancer Registry data for all CC operations (2001-2006). Hierarchical models predicted the adequacy of LN examination as a function of patient, surgeon, and hospital characteristics. Models were created using penalized quasi-likelihood approximation with second order Taylor linearization as implemented in MLwiN 2.15.

Results

A total of 25,606 resections involving 3376 surgeons operating in 346 hospitals were analyzed. Half of cases had an adequate examination. Hierarchical models showed the median odds of an adequate examination associated with the hospital context [(MORhosp 2.05; 95% confidence interval, 1.9-2.2) was much higher than that associated with the surgeon (MORsurg 1.34; 95% confidence interval, 1.2-1.4)]. Hospital characteristics teaching and high volume predicted higher odds of an adequate examination. There was no association with hospital revenue.

Conclusions

Approximately half of patients undergoing surgery for CC received an adequate LN examination. Hospital contextual factors had a stronger association with receipt of an adequate examination than surgeon factors. Our results suggest that quality improvement initiatives and incentives should be targeted at the hospital level to achieve the highest impact. Furthermore, we have identified nonteaching and low volume settings as rational targets for these efforts.