Report bias in drug research

Area of Science:

• Pharmacovigilance
• Clinical Trial Methodology
• Regulatory Science

Background:

• Selective reporting of clinical trial outcomes to regulatory authorities can lead to flawed marketing authorization decisions.
• This practice, termed 'report bias,' poses a significant risk to public health and drug safety.
• Understanding the extent and nature of report bias is crucial for ensuring the integrity of pharmaceutical regulation.

Purpose of the Study:

• To investigate the prevalence and characteristics of 'report bias' in clinical drug trials submitted to the Finnish National Agency for Medicines.
• To determine if incomplete reporting of trial outcomes is associated with specific study designs or phases.
• To identify potential factors contributing to the selective reporting of clinical trial results.

Main Methods:

• Retrospective analysis of clinical drug trial data notified to the Finnish National Agency for Medicines between 1987 and 1993.
• Comparison of reported versus non-reported trial outcomes based on study design, blinding, comparator use, and trial phase (I-IV).
• Statistical assessment to identify significant differences between reported and non-reported trial groups.

Main Results:

• Out of 274 clinical drug trials notified, outcomes for 183 (66.8%) were not reported by the end of 1993.
• No significant differences were found in study design, blinding, comparator use, or phase distribution between reported and non-reported trials.
• The lack of reporting was not attributable to variations in the investigational plans, suggesting other factors influence reporting.

Conclusions:

• A substantial proportion of clinical drug trials in Finland had unreported outcomes, indicating a significant issue with report bias.
• Incomplete reporting appears independent of study design, suggesting that factors such as trial results may influence the decision to report.
• Findings suggest that trials with results unfavorable to commercial interests may be less likely to be reported, necessitating further investigation and regulatory consideration.