Venebio has developed, validated, and deployed Venebio Opioid Advisor (VOA), a clinical decision support tool which predicts a patient’s individualized risk for serious prescription opioid overdose. Importantly, a standardized definition of serious opioid overdose has not yet been clearly established in the literature.


The VOA algorithm uses administrative claims codes to define serious opioid overdose. Notably, most available definitions and analyses of opioid overdose are limited to deaths or, less frequently, hospital admissions. In-hospital mortality has been reported to be approximately 1 to 2% of opioid overdose admissions,1,2 representing only a sliver of serious opioid overdose. Because a standardized definition of serious (fatal and non-fatal) overdose does not exist in the literature, it is important to examine the relationship between an overdose event as defined by the algorithm against the true incidence of overdose (as document in the clinical chart).


Venebio conducted a retrospective medical chart review whereby the previously established VOA claims coding algorithm identified a sample of 145 adult patients that presented to the emergency department of two large hospitals in metropolitan Atlanta, Georgia that met the criteria for serious opioid overdose as defined by the claims-based algorithm. Each case was evaluated against clinical definitions using literature-based clinical criteria for typical manifestations of opioid overdose and/or a clinical response to naloxone, an opioid-specific reversal agent. The positive predictive value (PPV) of the claims coding algorithm for a serious overdose event was calculated as the percentage of clinical cases confirmed by chart review (definite or probable).


One hundred and forty cases identified by the claims-based algorithm were evaluable. After clinical confirmation of these cases, 107 met clinical criteria for serious opioid overdose; PPV of 76.4% (95% CI 69.4%, 83.5%). Of the 30 non-confirmed cases, 20 were polyintoxications which did not allow for isolated examination of the effect of opioids on the patient’s reason for emergency department presentation. These results indicate a strong association between VOA’s claims-based algorithm for determining opioid overdose and its true, clinically confirmed occurrence.

Establishing a standardized definition for serious opioid overdose allows for enhanced disease surveillance and assessment of the impact of mitigation strategies like VOA and other public health initiatives. The results of this study were published in Pharmacoepidemiology and Drug Safety.

How Venebio addressed the challenge

When developing clinical decision support tools, the validity of the outcome definition itself (in this case, serious opioid overdose) is often overlooked. In order to ensure the VOA algorithm was built on a definition of serious opioid overdose that is strongly reflective of actual overdose events, a validation study was necessary.

The results of this study extend beyond its use in the VOA clinical decision support tool and into global surveillance efforts to assist with monitoring the impact of overdose risk mitigation strategies.
View the full publication here.

Epidemiology, Biostatistics, Advanced Analytics, and Real-World Evidence
Venebio Opioid Advisor

1. Hasegawa K, Brown DF, Tsugawa Y, Camargo CA. Epidemiology of emergency department visits for opioid overdose: a population-based study. Mayo Clin Proc. 2014;89(4):462-71.
2. Yokell MA, Delgado MK, Zaller ND, Wang NE, McGowan SK, Green TC. Presentation of prescription and nonprescription opioid overdoses to US emergency departments. JAMA Intern Med. 2014;174(12):2034-7.