Adverse Drug Reaction Reporting in the UK: a Retrospective Observational Comparison of Yellow Card Reports Submitted by Patients and Healthcare Professionals

Background: In the UK, spontaneous reporting of suspected adverse drug reactions (ADRs) by healthcare professionals has been in operation since 1964 through the Yellow Card Scheme (YCS). From 2005, patients themselves have been able to submit Yellow Card reports.

Objective: To compare patient characteristics, suspected drugs and suspected ADRs reported by patients with those reported by healthcare professionals using the YCS.

Design And Setting: Retrospective observational study in the UK.

Methods: Participants were patients reported to the Medicines and Healthcare products Regulatory Agency (MHRA), either by themselves, a representative or a healthcare professional, as having one or more suspected ADRs between October 2005 and September 2007. The main outcome measures were ADRs and time taken to report.

Results: In total, 26 129 Yellow Card reports from patients and healthcare professionals were received from the MHRA for the 2-year study period (19.8% patient and 80.2% healthcare professional). More Yellow Card reports were made for female than male patients (p < 0.001). Patients reported a significantly higher number of suspected ADRs per report than healthcare professionals (median [interquartile range {IQR}] of 3 [2-5] vs 2 [1-3], respectively; p < 0.001). A higher proportion of patient reports (16.1%) contained more than one suspect drug than healthcare professional reports (9%; p < 0.001). Healthcare professional reports had a higher proportion of ADRs that caused hospitalization (18.8% vs 12.9%), were life threatening (11.1% vs 6.2%) or caused death (2.6% vs 0.7%) than patient reports (all p < 0.001). Patient reporters took a significantly longer time to report their reaction than healthcare professionals (median [IQR] of 104 [27-463] vs 28 [13-75] days respectively; p < 0.001). Direct comparisons of the seriousness of the ADRs were not possible because of important differences between patient and healthcare professional versions of the Yellow Cards.

Conclusions: This is the first substantial, published study in the UK to compare Yellow Card reports from patients and healthcare professionals. Whilst patients report more suspected ADRs to more suspect drugs than healthcare professionals, healthcare professionals tend to report more serious reactions that result in hospitalization, are life threatening or cause death. Further research is required to investigate the extent to which the extra information from patient reporters contributes to signal identification when assessing drug safety.