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Background: Recurrent Clostridium difficile infection (CDI) is a significant problem due to its increased incidence and severity. Failure rates for standard antibiotic therapies are high. In our hospital, faecal microbiota transplantation (FMT), or instillation of a culture mixture of known enteric bacteria in saline as rectal bacteriotherapy (RBT), has long been used as 'rescue therapy' in patients with recurrent disease, in whom repeated courses of standard antibiotic treatment have failed. We wanted to evaluate the effectiveness of FMT and RBT for recurrent CDI. Methods: The records of 31 patients treated with either FMT or RBT for recurrent CDI were reviewed retrospectively. FMT was based on faecal donation by a close relative and RBT on a defined saline mixture of 10 individually cultured enteric bacterial strains originally isolated from healthy persons. Both types of instillation were carried out through a rectal catheter. FMT (500 ml) was given as 1 installation. RBT (200 ml) was given as 2 or 3 installations with an interval of 2 days between courses. Treatment success was defined as a sustained loss of symptoms and discontinuation of diarrhoea within 3 days. Results: Of 31 patients, 23 (74%) responded successfully to the treatment: 16 of 23 (70%) receiving FMT and 7 of 8 (88%) receiving RBT. Conclusion: We found FMT to be effective in patients with recurrent CDI. RBT based on a predefined bacterial suspension was as effective as or better than FMT based on faecal donation; however, multiple installations may be needed. [ABSTRACT FROM AUTHOR]

The article presents a study on the impacts of non-blinded outcome assessments on the predicted intervention effects of randomised clinical trials. The study used clinical trials from different sources such as PubMed, Embase and CINAHL, in which clinical trials with binary outcomes were included. Results show that non-blinded outcome assessments create significant biased treatment effect estimates.

Background: Clinical trials are commonly done without blinded outcome assessors despite the risk of bias. We wanted to evaluate the effect of nonblinded outcome assessment on estimated effects in randomized clinical trials with outcomes that involved subjective measurement scales., Methods: We conducted a systematic review of randomized clinical trials with both blinded and nonblinded assessment of the same measurement scale outcome. We searched PubMed, EMBASE, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, HighWire Press and Google Scholar for relevant studies. Two investigators agreed on the inclusion of trials and the outcome scale. For each trial, we calculated the difference in effect size (i.e., standardized mean difference between nonblinded and blinded assessments). A difference in effect size of less than 0 suggested that nonblinded assessors generated more optimistic estimates of effect. We pooled the differences in effect size using inverse variance random-effects meta-analysis and used metaregression to identify potential reasons for variation., Results: We included 24 trials in our review. The main meta-analysis included 16 trials (involving 2854 patients) with subjective outcomes. The estimated treatment effect was more beneficial when based on nonblinded assessors (pooled difference in effect size -0.23 [95% confidence interval (CI) -0.40 to -0.06]). In relative terms, nonblinded assessors exaggerated the pooled effect size by 68% (95% CI 14% to 230%). Heterogeneity was moderate (I(2) = 46%, p = 0.02) and unexplained by metaregression., Interpretation: We provide empirical evidence for observer bias in randomized clinical trials with subjective measurement scale outcomes. A failure to blind assessors of outcomes in such trials results in a high risk of substantial bias.

Objective: To evaluate the impact of non-blinded outcome assessment on estimated treatment effects in randomised clinical trials with binary outcomes., Design: Systematic review of trials with both blinded and non-blinded assessment of the same binary outcome. For each trial we calculated the ratio of the odds ratios--the odds ratio from non-blinded assessments relative to the corresponding odds ratio from blinded assessments. A ratio of odds ratios <1 indicated that non-blinded assessors generated more optimistic effect estimates than blinded assessors. We pooled the individual ratios of odds ratios with inverse variance random effects meta-analysis and explored reasons for variation in ratios of odds ratios with meta-regression. We also analysed rates of agreement between blinded and non-blinded assessors and calculated the number of patients needed to be reclassified to neutralise any bias., Data Sources: PubMed, Embase, PsycINFO, CINAHL, Cochrane Central Register of Controlled Trials, HighWire Press, and Google Scholar., Eligibility Criteria for Selecting Studies: Randomised clinical trials with blinded and non-blinded assessment of the same binary outcome., Results: We included 21 trials in the main analysis (with 4391 patients); eight trials provided individual patient data. Outcomes in most trials were subjective--for example, qualitative assessment of the patient's function. The ratio of the odds ratios ranged from 0.02 to 14.4. The pooled ratio of odds ratios was 0.64 (95% confidence interval 0.43 to 0.96), indicating an average exaggeration of the non-blinded odds ratio by 36%. We found no significant association between low ratios of odds ratios and scores for outcome subjectivity (P=0.27); non-blinded assessor's overall involvement in the trial (P=0.60); or outcome vulnerability to non-blinded patients (P=0.52). Blinded and non-blinded assessors agreed in a median of 78% of assessments (interquartile range 64-90%) in the 12 trials with available data. The exaggeration of treatment effects associated with non-blinded assessors was induced by the misclassification of a median of 3% of the assessed patients per trial (1-7%)., Conclusions: On average, non-blinded assessors of subjective binary outcomes generated substantially biased effect estimates in randomised clinical trials, exaggerating odds ratios by 36%. This bias was compatible with a high rate of agreement between blinded and non-blinded outcome assessors and driven by the misclassification of few patients.