OBJECTIVE: To explore if there is a difference between patients and healthcare professionals (HCPs) in time to reporting drug-adverse drug reaction (ADR) associations which led to drug safety signals.

DESIGN: This was a retrospective comparison of time to reporting selected drug-ADR associations which led to drug safety signals between patients and healthcare professionals.

SETTING: ADR reports were selected from the World Health Organization Global database of individual case safety reports, VigiBase. Reports were selected based on drug-ADR associations of actual drug safety signals.

MAIN OUTCOME MEASURES: Primary outcome was the difference in time to reporting between patients and HCPs. The date of the first report for each individual signal was used as time zero. The difference in time between the date of the reports and time zero was calculated. Statistical differences in timing were analysed on the corresponding survival curves using a Mann-Whitney U test.

RESULTS: In total 2822 reports were included, of which 52.7% were patient reports, with a median of 25% for all included signals. For all signals, median time to signal detection was 10.4 years. Overall, HCPs reported earlier than patients: median 7.0 vs 8.3 years (p <0.001).

CONCLUSIONS: Patients contributed a large proportion of reports on drug-ADR pairs that eventually became signals. HCPs reported 1.3 year earlier than patients. These findings strengthen the evidence on the value of patient reporting in signal detection, and highlight an opportunity to encourage patients to report suspected ADRs even earlier in the future.