Drug safety surveillance strongly depends on the spontaneous and voluntary reporting of adverse drug reactions (ADR). A major limiting factor of spontaneous reporting systems is underreporting (UR) which describes incorrectly low reporting rates of ADR. Factors contributing to UR are numerous and feature country-dependent differences.

Understanding causes of UR is necessary to facilitate targeted interventions to improve ADR reporting and pharmacovigilance.

A cross-sectional questionnaire-based telephone survey was performed among physicians in outpatient care in a federal state of Germany.

From n = 316 eligible physicians n = 176 completed the questionnaire (response rate = 55.7%). Most of the physicians (n = 137/77.8%) stated that they report ADR, which they have observed to the competent authority rarely (n = 59/33.5%), very rarely (n = 59/33.5%) or never (n = 19/10.8%); the majority (n = 123/69.9%) had not reported any ADR in 2014. Frequent subjective reasons for ADR non-reporting were (specified response options): lack of time (n = 52/29.5%), the subjective evaluation that the required process of reporting is complicated (n = 47/26.7%) or requires too much time (n = 25/14.2%) or the assessment that reporting of an ADR is needless (n = 22/12.5%); within free answers the participants frequently stated that they do not report ADR that are already known (n = 72/40.9%) and they only report severe ADR (n = 46/26.1%).

Our results suggest a need of interventions to inform physicians about pharmacovigilance and to modify the required procedure of ADR reporting or to offer other reporting options.

The authors have not supplied their declaration of competing interest.