Risk factors for urinary tract infections in colorectal compared with vascular surgery: a need to review current present-on-admission policy?

BACKGROUND

To reduce cost, the Centers for Medicare and Medicaid Services adopted a nonpayment policy for "reasonably preventable events" including hospital acquired urinary tract infection (UTI). Type of operation a patient undergoes could be an inevitable nonmodifiable risk factor in the development of UTI.

STUDY DESIGN

Using Participant User File for National Surgical Quality Improvement Program (NSQIP) data from 2005 to 2007, vascular and colorectal cases were identified using CPT codes and analyzed for UTI incidence and risk factors within each group.

RESULTS

We identified 30,900 colorectal cases and 39,246 vascular cases with 1,289 (4.2%) colorectal and 952 (2.4%) vascular UTI cases. A multivariate analysis of the dataset revealed colorectal procedures as an independent risk factor for the development of UTI. Subset analysis revealed this significant relationship only for patients with low (<0.30) and intermediate (0.30 to 0.70) morbidity probability. Comparing only open intra-abdominal colorectal and vascular procedures revealed UTI rates of 3.9% versus 4.7%. Multivariate analysis revealed no significant difference in UTI rates in intraabdominal cases (all p values < 0.05). Subset analysis for the open cases revealed that colorectal procedures continued to be associated with UTI in low morbidity probability cases only.

CONCLUSIONS

Current policy to reward higher quality fails to differentiate between UTI that may be preventable versus one likely due to nonmodifiable risk factors. Colorectal surgery is more likely to result in higher rates of UTI in comparison with vascular surgery, which may be related to type and complexity of a procedure. Further research needs to be done to change this policy to take into account this nonmodifiable risk factor.