Table 2.
Mann Whitney U Test for Significant Differences by Year Between Fentanyl and Common Prescription Opioids1 as Measured by the Relative Similarity Ratio (RSR).
| Year | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 |
| p-value | 3.88e–01 | 1.01e–03 | 6.97e–09 | 1.36e–10 | 3.31e–19 | 1.48e–22 | 1.53e–24 | 1.07e–21 |
Note: The Relative Similarity Ratio compares the strength of the semantic association between fentanyl and overdose to the strength of the semantic association between the common prescription opioids and overdose.
1
Common prescription opioid terms include: oxycodone, oxy, roxy, percocet, oxycontin, hydrocodone, vicodin, hydromorphone, dilaudid, morphine