Demers 2014.
| Methods | Study design: placebo‐controlled RCT, 3 parallel groups Duration of the study, recruitment: 2006 to 2010 Follow‐up: maximum duration of follow‐up was 10 weeks Country: Canada |
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| Participants | Participants (≥ 18 years old) with pelvic (gynaecological, rectal, or prostate) cancer and ECOG performance status of 0 or 1 who were to receive radiotherapy treatments at a minimum of 40 Gy at the pelvic level, with or without chemotherapy
Exclusion criteria: previous radiotherapy treatment in the pelvic or abdominal region, medical history of gastrointestinal disorders, pregnancy, breastfeeding, neutropenia, probiotic intolerance Participant characteristics (standard dose versus higher dose versus placebo), n (%):
Mean age, years: 61.4 versus 62.0 versus 60.6 Male sex, n (%): 58 (72) versus 39 (66) versus 56 (63) "The data reveal that the participants were well distributed among groups and protocol fidelity exceeded 90% in each of the three groups" |
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| Interventions | Intervention 1 (n = 91 randomised, n = 81 analysed): standard dose of double‐strain Bifilact probiotics (Lactobacillus acidophilus LAC‐361 and Bifidobacterium longum BB‐536) twice a day (1.3 billion CFU) Intervention 2 (n = 64 randomised, n = 59 analysed): high dose of double‐strain Bifilact probiotics (Lactobacillus acidophilus LAC‐361 and Bifidobacterium longum BB‐536) 3 times a day (10 billion CFU) Control group: placebo (n = 91 randomised, n = 86 analysed) |
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| Outcomes | Proportion of participants with diarrhoea, quality of life (EORTC‐QLQ‐C30), need for antidiarrhoeal medication, number of bowel movements, abdominal pain, stool consistency, compliance, number of hospitalisations, number of treatment interruptions, and reduction in chemotherapy doses or radiotherapy treatments as a result of severe diarrhoea or abdominal pain | |
| Notes | Trial registration: NCT01839721; number analysed in the control group (86) based on Table 2 of the study report | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "Patients were block‐randomised by the research nurse according to the random list generated by blocks of 2, 4,or 6 patients, according to random permutations [...] another random block using higher probiotics dosage to the randomization was added with preservation of the double blind. New random lists were generated for each stratum with a 3:1:1 ratio (higher dose, standard dose, placebo) to compensate for the late start of the higher dose group" |
| Allocation concealment (selection bias) | High risk | "All the bottles had a similar appearance; they were all identified by the commercial brand Bifilact. Also the group, either A, B or C, was circled on that bottle, depending on whether that bottle belonged to the placebo group, standard dose group, or high dose group. Only the nurse knew the coding system, the nurse also assigned the patient to a group, according to the randomization list" |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | "The two registered dieticians and caregivers were blinded to these processes to preserve the double blind" Participants were blinded as well |
| Blinding of outcome assessment (detection bias) Subjective outcomes | Low risk | "The two registered dieticians and caregivers were blinded to these processes to preserve the double blind" Participants were blinded as well |
| Blinding of outcome assessment (detection bias) Objective outcomes | Low risk | No information; however it is unlikely that assessment of objective outcomes (mortality) would have been influenced |
| Incomplete outcome data (attrition bias) Subjective outcomes | Unclear risk | n = 17 dropped out before first radiotherapy (standard‐dose group n = 10, high‐dose group n = 5, placebo group n = 2) and were excluded from the analysis. Not clear whether this may have influenced the results n = 7 discontinued intervention (standard‐dose group n = 1, high‐dose group n = 3, placebo group n = 3); however all were analysed in the group to which they were randomised |
| Incomplete outcome data (attrition bias) Objective outcomes | Unclear risk | Survival status of 17 excluded participants was unknown |
| Selective reporting (reporting bias) | Low risk | Outcomes reported in publication correspond to outcomes prespecified in study protocol |
| Other bias | Low risk | No indication of other bias |