Older age , use of antibiotics after diagnosis , use of proton pump inhibitors , and strain type were the most frequent risk factors for recurrence .
Older age , leucocytosis , renal failure and co-morbidities were frequent risk factors for complicated CDI .
When considered alone , mortality was associated with age , co-morbidities , hypo-albuminemia , leucocytosis , acute renal failure , and infection with ribotype 027 .
BACKGROUND Clostridium difficile infection ( CDI ) can lead to complications , recurrence , and death .
Numerous studies have assessed risk factors for these unfavourable outcomes , but systematic review s or meta-analyses published so far were limited in scope or in quality .
Effect of age on treatment outcomes in Clostridium difficile infection.
OBJECTIVES To determine the effect of advancing age on the clinical outcomes of Clostridium difficile ( CDI ) treatment .  DESIGN Regression modeling of results from two double-blind r and omized multicenter studies on the treatment of primary and first recurrent cases of CDI to examine for effects of age and study drug on outcomes of cure ( resolution of diarrhea ) , recurrence within 4 weeks of completing successful therapy , and cure without recurrence . SETTING Participants were r and omized into studies in the United States , Canada , and Europe . PARTICIPANTS Nine hundred ninety-nine individuals with toxin-positive CDI were r and omized to receive vancomycin ( 125 mg 4 times daily ) or fidaxomicin ( 200 mg twice daily ) for 10 days . MEASUREMENTS The effect of advancing age  in those aged 18 to 40 years and in 10-year increments thereafter was examined . RESULTS The model predicts a 17 % lower clinical cure , 17 % greater recurrence , and 13 % lower sustained clinical response by advancing decade than in those younger than 40 ( P < .01 each ) . Clinical cure was similar in the fidaxomicin and vancomycin treatment groups , although fidaxomicin was associated with a more than 50 % lower relative risk for recurrence than vancomycin ( P < .001 ) . Multivariate regression modeling showed that risk factors accounting for poorer outcomes with advancing age include infection with the BI strain type , inpatient status , renal insufficiency , leukocytosis , hypoalbuminemia , and concomitant medication exposure . CONCLUSION Measurable and progressive deterioration in CDI treatment outcomes occurred with advancing age in those aged 40 and older , highlighting the need for prevention and treatment strategies . Fidaxomicin treatment was associated with a 60 % lower risk of recurrence than vancomycin after adjusting for age , concomitant antibiotics , and C. difficile strain
Older age , use of antibiotics after diagnosis , use of proton pump inhibitors , and strain type were the most frequent risk factors for recurrence .
Older age , leucocytosis , renal failure and co-morbidities were frequent risk factors for complicated CDI .
When considered alone , mortality was associated with age , co-morbidities , hypo-albuminemia , leucocytosis , acute renal failure , and infection with ribotype 027 .
BACKGROUND Clostridium difficile infection ( CDI ) can lead to complications , recurrence , and death .
Numerous studies have assessed risk factors for these unfavourable outcomes , but systematic review s or meta-analyses published so far were limited in scope or in quality .