Social Risk Factors Associated With Post-Colectomy Surgical Site Infections

Infection prevention programs targeting low-income groups undergoing colectomy may be important in reducing surgical site infections (SSIs), according to a study published in JAMA Network Open.

Nationally, SSIs complicate up to 5% of surgical procedures and are associated with significant morbidity, mortality, and postoperative costs; however, SSIs are often preventable. Reducing SSI incidence has thus become a national priority for patient safety efforts. Strategies to reduce SSIs have included public reporting of hospital performance and financial incentives, making the risk-adjustment methods that hospitals used for SSI have significant consequences in either public reputation or financial stability. Although diabetes, sex, obesity, and age have been incorporated into SSI risk adjustment models, no adjustments have been made for social risk factors.

A better understanding of whether social risks that are associated with SSI for colectomy and abdominal hysterectomy, as well as whether accounting for these factors would change hospital performance on these measures, may have significant implications for public reporting and value-based payment models. However, such studies are sparse in the literature. Therefore, this cross-sectional study aimed to determine whether social risk factors were associated with higher rates of SSI after colectomy or abdominal hysterectomy. Both colectomy and abdominal hysterectomy were selected because SSI rates for these procedures are publically reported and are included in pay-for-performance programs by Medicare and other groups.

In total, 149,741 patients were included: 90,210 patients undergoing colectomies and 59,531 patients undergoing abdominal hysterectomies. Data were collected on surgeries that were performed between 2013 and 2014 at general acute hospitals via the State Inpatient Database for the following states: Arizona, Florida, Iowa, Massachusetts, Maryland, New York, and Vermont. The main outcome was postoperative complex SSI rates. The social risk factors analyzed included race/ethnicity, insurance status, and neighborhood income.

Results showed inconsistent associations between SSIs and social risk factors. In the colectomy cohort, patients had a mean age of 63.4 years and were majority women (54%) and white (74%); 11% were black, 9% were Hispanic, and 5% were other or unknown. In addition, 34% of patients had private insurance, 52% had Medicare, 9% had Medicaid, and 5% had unknown insurance or were uninsured. The postsurgery SSI rates in this cohort was 2.55%. Results also showed that 25% of these patients were from the lowest-income Zip codes. The colectomy cohort also demonstrated that Medicare, Medicaid, and lower neighborhood income were all associated with higher risk for SSI (adjusted odds ratio [aOR], 1.23, 1.25, and 1.14, respectively); black race was associated with lower risk for SSI compared with their white counterparts (2.27% vs 2.62%; aOR, 0.71).

In the abdominal hysterectomy cohort, patients had a mean age of 49.8 years and were all women; 52% were white, 26% were black, 14% were Hispanic, and 8% were other or unknown. Further, 57% of patients in this cohort had private insurance, 16% had Medicare, 19% had Medicaid, and 3% had unknown insurance or were uninsured. In total, 27% of patients were from the lowest-income Zip codes. The postsurgery SSI rate was 0.61% for this cohort. After adjustment for clinical risk, no social risk factors studied had statistically significant associations with SSI rate for the abdominal hysterectomy cohort.

Overall, the study authors concluded that, “The outcomes of patient safety-focused pay-for-performance programs on health care systems serving socially at-risk populations should be closely monitored to identify disparities and opportunities for improvement.”

Reference

Qi AC, Peacock K, Luke AA, Barker A, Olsen MA, Maddox KE. Associations between social risk factors and surgical site infections after colectomy and abdominal hysterectomy. JAMA Network Open. 2019;2(10):e1912339.