Preoperative Care Assessment of Need Scores Are Associated With Postoperative Mortality and Length of Stay in Veterans Undergoing Knee Replacement.
BACKGROUND: Care Assessment of Need (CAN) scores predicting 90-day mortality and hospitalization are automatically computed each week for patients receiving care at Veterans Health Administration facilities. While currently used only by primary care teams for care coordination, we explored their value as a perioperative risk stratification tool before major elective surgery. METHODS: We collected relevant demographic and perioperative data along with perioperative CAN scores for veterans who underwent total knee replacement between July 2014 and December 2015. We examined score distribution, relationships of preoperative CAN 1-year mortality scores with 1-year postoperative mortality and index hospital length of stay (LOS), and patterns of mortality. RESULTS: Among 8206 patients, 1-year mortality was 1.4% (110 patients), and CAN scores exhibited near-normal distribution. Median scores among survivors were significantly higher than those of in nonsurvivors (45 vs 75; P < .001). The Kaplan-Meier curves showed an approximately 4-fold higher rate of death at 1 year in the highest tercile for 1-year mortality CAN scores compared with those with lower scores (2.0% vs 0.5% respectively; P < .001). Locally estimated scatterplot smoothing curves revealed a significant and nonlinear increase in hospital LOS across preoperative CAN scores. CONCLUSIONS: Although designed for ambulatory care use, CAN scores can identify patients at high risk for mortality and extended hospital LOS in an elective surgery population. The CAN scores may prove valuable in supporting informed decision making and preoperative planning in high-risk and vulnerable populations. Further study is needed to confirm the validity of CAN scores and compare them to other more widely used surgical risk calculators.
