The PRR is a signal detection method used in postmarketing drug and vaccine safety surveillance [1].

The PRR is the proportion of spontaneous reports for a given drug that are linked to a specific adverse event outcome, divided by the corresponding proportion for all (or several other) drugs [2]. Note that PRR is one of a number of commonly used safety-signal detection techniques. The use of the PRR by FDAble is not an endorsement of PRR as being superior to other methods.

FDAble provides the only public search engine for generating PRR data.
Download Sample PRR Report.
See limitations of safety-signal detection techniques like the PRR.
See guidance for generating and evaluating PRR reports.

Click for an Example PRR

The PRR Report provides Proportional reporting ratios for more than 17,000 types of adverse event. As an example, Figure 1 shows a chart of PRRs for the anti-cholesterol medication Baycol®, which was withdrawn from the U.S. market in August, 2001 in response to reports that its use was associated with rhabdomyolysis (muscle wasting) and other muscular pathologies.

The data in Figure 1 show PRRs for 3 adverse events specifically related to muscular physiology (rhabdomyolysis, myositis, myopathy) along with 10 randomly chosen adverse events (asthenia, cardiac failure, chest pain, dizziness, haemorrhage nos, headache, hepatitis nos, syncope, urticaria, and weakness). The muscle-related adverse events have PRRs of 55, 23 and 24, respectively. Interestingly, these data were generated using only information submitted to the FDA prior to November, 1999.