Details about what was done and what was found in clinical trials looked at by the German Institute for Quality and Efficiency in Health Care (IQWiG) are incomplete or missing from publicly available trial information according to a new study published in The BMJ. The researchers at IQWiG, who wrote the study, conclude that “a substantial amount of information needed for assessment of the corresponding clinical studies and for understanding of the drug’s benefits and harms is missing in publicly available European public assessment reports, journal publications, and registry reports.” They suggest that full reports of clinical trials should be made public.

Since 2011 when a new drug is approved in Germany pharmaceutical companies have to submit a dossier with all the evidence that their drug is more beneficial than existing treatments, this includes unpublished information and clinical study reports. IQWiG evaluates the information in those dossiers to inform the government’s pricing negotiations with pharma companies. IQWiG then publishes its analysis and the main parts of the dossier online.

Researchers at IQWiG wanted to compare the information available in these dossiers with the information that is publicly available in journal publications, reports on clinical trial registries and regulatory reports produced by the European Medicines Agency. They looked 15 dossiers that included information from 22 clinical trials. For each trial, they checked whether complete information about the methods and results was available in the dossiers and publicly available sources. The dossiers contained complete information for about 90% of the methods and results sections, while publicly available sources contained complete information for 75% of the methods sections and 52% of the results sections. The researchers also found that the publicly available trial information included very few details about outcomes for different subgroups of patients, compared with the information contained in the dossiers.