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 .
Impact of the type of diagnostic assay on Clostridium difficile infection and complication rates in a mandatory reporting program.
BACKGROUND Most Clostridium difficile infection ( CDI ) surveillance programs neither specify the diagnostic method to be used nor stratify rates accordingly . We assessed the difference in  healthcare-associated CDI ( HA-CDI ) incidence and complication rates obtained by 2 vali date d diagnostic methods . METHODS This was a prospect i ve cohort study of patients for whom a C. difficile test was ordered between 1 August 2010 and 31 July 2011 . All specimens were tested in parallel by a commercial polymerase chain reaction ( PCR ) assay targeting toxin B gene tcdB , and a 3-step algorithm detecting glutamate dehydrogenase and toxins A and B by enzyme immunoassay and cell culture cytotoxicity assay ( EIA/CCA ) .  CDI incidence rate ratios were calculated using univariate Poisson regression . RESULTS A total of 1321 stool sample s were tested during a period totaling 95 750 patient-days . Eighty-five HA-CDI cases were detected by PCR and 56 cases by EIA/CCA ( P = .01 ) . The overall incidence rate was 8.9 per 10 000 patient-days ( 95 % confidence interval [ CI ] , 7.1 - 10.9 ) by PCR and 5.8 per 10 000 patient-days ( 95 % CI , 4.4 - 7.4 ) by EIA/CCA ( P = .01 ) . The incidence rate ratio comparing PCR and EIA/CCA was 1.52 ( 95 % CI , 1.08 - 2.13 ; P = .015 ) . Overall complication rate was 27 % ( 23/85 ) when CDI was diagnosed by PCR and 39 % ( 22/56 ) by EIA/CCA ( P = .16 ) . Cases detected by PCR only were less likely to develop a complication of CDI compared with cases detected by both PCR and EIA/CCA ( 3 % vs 39 % , respectively ; P < .001 ) . CONCLUSIONS Performing PCR instead of EIA/CCA is associated with a > 50 % increase in the CDI incidence rate . St and ardization of diagnostic methods may be indicated to improve interhospital comparison
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 .