Quality of Reporting in Clinical Trials of Preharvest Food Safety Interventions and Associations with Treatment Effect

Randomized controlled trials (RCTs) are the gold standard for evaluating treatment efficacy. Therefore, it is important that RCTs are conducted with methodological rigor to prevent biased results and report results in a manner that allows the reader to evaluate internal and external validity. Most human health journals now require manuscripts to meet the Consolidated Standards of Reporting Trials (CONSORT) criteria for reporting of RCTs. Our objective was to evaluate preharvest food safety trials using a modification of the CONSORT criteria to assess methodological quality and completeness of reporting, and to investigate associations between reporting and treatment effects. One hundred randomly selected trials were evaluated using a modified CONSORT statement. The majority of the selected trials (84%) used a deliberate disease challenge, with the remainder representing natural pathogen exposure. There were widespread deficiencies in the reporting of many trial features. Randomization, double blinding, and the number of subjects lost to follow-up were reported in only 46%, 0%, and 43% of trials, respectively. The inclusion criteria for study subjects were only described in 16% of trials, and the number of animals housed together was only stated in 52% of the trials. Although 91 trials had more than one outcome, no trials specified the primary outcome of interest. There were significant bivariable associations between the proportion of positive treatment effects and failure to report the number of subjects lost to follow-up, the number of animals housed together in a group, the level of treatment allocation, and possible study limitations. The results suggest that there are substantive deficiencies in reporting of preharvest food safety trials, and that these deficiencies may be associated with biased treatment effects. The creation and adoption of standards for reporting in preharvest food safety trials will help to ensure the inclusion of important trial details in all publications.