Gastrointestinal Comorbidities Increase Risk of C Difficile for Patients with UTIs

Ivy Ge, PharmD

Female sex, previous gastrointestinal comorbidity, and non-gastrointestinal comorbidity were independently associated with a higher risk of community-acquired Clostridium difficile infection in patients with urinary tract infection (UTI), according to a study published in Therapeutic Advances in Urology.

“The findings from our study of particularly interest for primary care physicians, infectious disease physicians, as well as urologists and urogynecologists in an age where we are seeing the various repercussions of our increasing antibiotic use,” Ivy Ge, PharmD, of Kaiser Permanente South San Francisco, told MD Magazine®. “This research is also especially important due to the prevalence of UTI, especially in female population. We hope this study will provide greater insight for physicians who treat patients with UTI and co-occurring [community acquired C difficile infection].”

Researchers from Kaiser Permanente Northern California performed a nested case-control study of adult patients who received ≥1 antibiotic prescription for acute uncomplicated UTI between 2007-2010. Cases reported loose stools and had a positive test for C difficile for ≥3 days following the start of an antibiotic regimen and <90 days following stopping their antibiotic regimen (n = 68). Each case was matched with a total of 2 randomly selected age-matched controls who had antibiotic-treated UTI but no diagnosis of C difficile (n = 112).

The investigators classified antibiotics as low risk (eg, nitrofurantoin and sulfamethoxazole/trimethoprim), moderate risk, high risk (eg, cefpodoxime, ceftriaxone, and clindamycin), and most common (eg, ciprofloxacin) for C difficile infection. The primary measurement of interest was the association between antibiotic treatment of uncomplicated UTI and history of gastrointestinal comorbidity with community-acquired C difficile infection risk. Gastrointestinal comorbidities included gastrointestinal diagnoses, procedures, and gastric acid suppression treatment.

In the adjusted analysis, factors associated with C difficile risk included past gastrointestinal comorbidities (OR 2.3; 95% CI 1.1-4.8) and Charlson comorbidity (OR 2.8; CI 1.4-5.6). Additionally, non-gastrointestinal comorbidities were associated with community-acquired C difficile (prevalence 6%; OR 2.8; 95% CI 1.4-5.6). Treatment with ciprofloxacin (OR 2.7; 95% CI 1.0-7.2), moderate-risk antibiotics (OR 3.6; 95% CI 1.2-11), and high-risk antibiotics (OR 11.2; 95% CI 2.4-52) compared with low-risk antibiotics.

Compared with men, women presented with a 6.3-fold greater risk for C difficile (95% CI 1.7-24). A subgroup analysis in women demonstrated that there was an association between a higher risk for C difficile and the use of ciprofloxacin (OR 2.9; 95% CI 1.1-8.0), moderate risk (OR 3.7; 95% CI 1.2-11), and high risk (OR 8.0; 95% CI 1.8037) compared with low-risk agents. Additionally, women had a higher risk if they had a history of Charlson comorbidity (OR 2.2; 95% CI 1.0-4.9) and gastrointestinal comorbidities (OR 3.0; 95% CI 1.5-6.2).

Limitations of this study include its relatively small sample size, inclusion of patients from a single center, and the high prevalence of female patients in the overall cohort.

“Since many clinicians are able to identify at-risk patients by examining their medical histories, they should have the ability to switch these patients to lower-risk options, particularly with this high-risk cohort,” Ge added. “Additional research, in addition to public health efforts to promote improved hygiene, sexual practices, and health behaviors among girls and women, is needed to further reduce the morbidity associated with UTIs and antibiotic use for UTI treatment.”

The study, “Reducing risk of Clostridium difficile infection and overall use of antibiotic in the outpatient treatment of urinary tract infection,” was published in Therapeutic Advances in Urology.