The quality metric prolonged length of stay misses clinically important adverse events.

BACKGROUND

The National Quality Forum endorses prolonged length of stay of more than 14 days (PLOS) as a quality metric for lobectomy for lung cancer. Because PLOS rates are lower than complication rates, we hypothesized that PLOS misses a significant proportion of clinically important events.

METHODS

A retrospective study was performed on patients undergoing lobectomy (2000 to 2009). The severity of adverse events was based on the National Cancer Institute common terminology criteria for adverse events (grade 2 or higher indicates symptoms or need for medical intervention; grade 5 indicates death).

RESULTS

Among 2,667 patients, 163 (6%) experienced PLOS and 773 (29%) experienced an adverse event. Although the frequency of adverse events was higher among the PLOS group (99% [161 of 163] versus 24% [612 of 2504]), 79% (612 of 773) of adverse events occurred in the non-PLOS group. Whereas PLOS was associated with more severe events, 89% of those in the non-PLOS group experienced a grade 2 or higher event. Likewise, although PLOS was associated with the lowest 5-year survival rate (31%), patients in the non-PLOS group who had an adverse event had significantly lower survival rates than patients in the non-PLOS group who did not have any adverse events (55% versus 68%, p<0.001; adjusted hazard ratio 1.3 [95% confidence interval: 1.1 to 1.6]).

CONCLUSIONS

The PLOS missed a high proportion of adverse events defined by the need for ongoing inpatient therapy and an association with poor long-term survival. These findings have implications for efficient and fair performance assessment in the setting of a quality improvement program.