Reporting on risks often inadequate for prebiotics, probiotics, synbiotics
Researchers reviewed studies that discussed the safety or efficacy of at least one intervention involving probiotics, prebiotics, or synbiotics alone or in combination with another intervention compared with any control for any clinical condition.
Assessment of potential risks and harms of probiotics, prebiotics, and synbiotics often is lacking or inadequate in research, a recent study cautioned.
To examine how harms-related information is reported in publications of randomized controlled trials of probiotics, prebiotics, and synbiotics, researchers reviewed studies published from January 2015 through March 2018 that discussed the safety or efficacy of at least one intervention involving probiotics, prebiotics, or synbiotics alone or in combination with another intervention compared with any control (such as a placebo or an antibiotic) for any clinical condition. Results were published July 17 by Annals of Internal Medicine.
Of 384 trials, most evaluated probiotics (n=265 [69%]). Nine of the 384 trials (2%) adequately reported methods of harm assessment and defined adverse events (AEs), the mode used to collect data, the timing, and attribution methods. Twenty-three trials (6%) adequately described safety results with the number of participant withdrawals due to harms and the number of AEs and serious adverse events (SAEs), with appropriate metrics and a denominator used for safety analysis, the authors concluded. Nine trials (2%) adequately reported all guideline-recommended parameters (number of participant withdrawals due to harms; definition of AEs and SAEs; number of AEs per study group; and grade, type, and seriousness, with denominators used for analysis).
No harms-related data were reported for 106 trials (28%), safety results were not reported for 142 trials (37%), and the number of serious adverse events (SAEs) per study group was not reported for 309 trials (80%). Harms reporting for these interventions often was missing, insufficient, or inadequate, the authors noted. Of 242 studies that mentioned harms-related results, 37% (n=89) used only generic statements to describe AEs (such as “well-tolerated”). In addition, 16% (n=38) used inadequate metrics (such as only percentages) or restricted AE reporting to common, severe, or unexpected events. Overall, 375 trials (98%) did not define AEs or SAEs, the number of participant withdrawals due to harms, or the number of AEs and SAEs per study group with denominators.
Physicians cannot conclude that these supplements are safe if data on safety are not adequately reported, the authors noted.
“The inadequacy in reporting harms-related results may lead to an inaccurate safety profile and erroneous decision making, with major consequences for patients,” they wrote. “For example, a generic statement, such as ‘well-tolerated,’ may be misinterpreted as a lack of AEs reported for a trial, but the reader cannot determine whether no AEs occurred in any participants, the AEs were not measured or reported, or both. Readers should be able to estimate the number of AEs, even if no events occur.”
ACP Internist most recently covered the human microbiome in its Internal Medicine Meeting 2018 coverage in the July/August 2018 issue.