Prevalence of Prescription Opioid Misuse/Abuse as Determined by International Classification of Diseases Codes: A Systematic Review

ABSTRACT

We conducted a systematic review to evaluate worldwide human English published literature from 2009 to 2014 on prevalence of opioid misuse/abuse in retrospective databases where International Classification of Diseases (ICD) codes were used. Inclusion criteria for the studies were use of a retrospective database, measured abuse, dependence, and/or poisoning using ICD codes, stated prevalence or it could be derived, and documented time frame. A meta-analysis was not performed. A qualitative narrative synthesis was used, and 16 studies were included for data abstraction. ICD code use varies; 10 studies used ICD codes that encompassed all three terms: abuse, dependence, or poisoning. Eight studies limited determination of misuse/abuse to an opioid user population. Abuse prevalence among opioid users in commercial databases using all three terms of ICD codes varied depending on the opioid; 21 per 1000 persons (reformulated extended-release oxymorphone; 2011–2012) to 113 per 1000 persons (immediate-release opioids; 2010–2011). Abuse prevalence in general populations using all three ICD code terms ranged from 1.15 per 1000 persons (commercial; 6 months 2010) to 8.7 per 1000 persons (Medicaid; 2002–2003). Prevalence increased over time. When similar ICD codes are used, the highest prevalence is in US government-insured populations. Limiting population to continuous opioid users increases prevalence. Prevalence varies depending on ICD codes used, population, time frame, and years studied. Researchers using ICD codes to determine opioid abuse prevalence need to be aware of cautions and limitations.

KEYWORDS:

• abuse
• dependence
• opioid
• poisoning
• prevalence
• systematic review

Acknowledgment

This study was initially presented as a poster at the International Society for Pharmacoeconomics and Outcome Research 21st Annual International Meeting in Washington, DC, May 2016.

Funding

This study was sponsored by Pfizer, Inc.

Declaration of interest

Gary Oderda and Joanita Lake are employees of the University of Utah, College of Pharmacy, which received financial support from Pfizer in connection with the study and development of this manuscript. Carl L. Roland is an employee of Pfizer.