Do Mixed-Flora Preoperative Urine Cultures Matter?

Area of Science:

• Urology
• Gynecology
• Infectious Disease

Background:

• Preoperative urine cultures are routinely performed before urogynecologic surgery.
• Interpretation of mixed-flora urine cultures can be challenging.
• The clinical significance of mixed-flora results in predicting postoperative urinary tract infections (UTIs) is unclear.

Purpose of the Study:

• To compare the prevalence of postoperative UTIs in women with mixed-flora versus no-growth preoperative urine cultures.
• To determine if mixed-flora preoperative urine cultures are associated with an increased risk of postoperative UTIs.

Main Methods:

• Retrospective cohort study of 282 women undergoing urogynecologic surgery.
• Patients were divided into two groups: mixed-flora or no-growth preoperative urine cultures.
• Postoperative UTI treatment rates were compared between groups, controlling for confounding variables using logistic regression.

Main Results:

• No significant difference in the proportion of patients treated for postoperative UTIs between the mixed-flora and no-growth cohorts (14% overall).
• Logistic regression analysis confirmed no increased risk of postoperative UTI with mixed-flora cultures (adjusted odds ratio 0.92).
• The prevalence of postoperative UTI was similar regardless of preoperative urine culture findings.

Conclusions:

• Mixed-flora preoperative urine cultures are not associated with a higher prevalence of postoperative UTIs.
• The clinical practice of treating mixed-flora urine cultures as negative is appropriate and supported by this study.
• This finding supports current clinical guidelines and may reduce unnecessary interventions.