Comparative Analysis of Opioid Queries on Erowid.org: An Opportunity to Advance Harm Reduction.

Background: Many individuals who use opioids turn to online resources to gather information on effects, availability, and safety. Objective: Describe opioid index page views on Erowid. org to assess trends in public interest in particular opioids. Methods: Retrospective analysis of Erowid. org site traffic was performed to identify unique average daily visits to opioid pages. All data was normalized to that of visits to the heroin index page. Average daily visits to the index pages of each of 6 commonly abused opioids were assessed during the period of 2009 to 2015. Similarly, visits to 15 distinct opioid index pages at 5 time points (July, October 2014 and Jan, April, and July 2015) were described. Results: From 2009 to 2015 a decrease in the number of page visits versus heroin (1.00) occurred for hydrocodone (0.87 to 0.59, -32%), oxycodone (1.38 to 0.99, -28%), and morphine (0.26 to 0.25, -6%). Increases in page visits compared to heroin occurred for fentanyl (0.18 to 0.47, +157%), tramadol (0.43 to 0.88, +106%), hydromorphone (0.19 to 0.24, +29%), and oxymorphone (0.11 to 0.13, +18%). Indexed to heroin (1.00) average opioid page visit frequencies from July 2014 to July 2015 were highest for oxycodone (1.02) and tramadol (0.81). Conclusion/Importance: Oxycodone and tramadol represent the greatest number of Erowid. org opioid page visits compared to heroin. The largest increase in visits over the study periods was for fentanyl and tramadol. The relationship of page visits on Erowid. org creates a unique opportunity for real-time evaluation of emerging drug trends and epidemiological study.