Opioid-Related Mortality, Morbidity, & Prescriptions

Calendar year 2016 marked the peak of opioid overdose deaths in Orange County (n=288, 9.1 per 100,000) – a 25% increase from 2012 which had the lowest number of opioid overdose deaths (n=224, 7.3 per 100,000) during this eight-year period. A decreasing rate (-13%) trend is seen after 2016 with the most recent rate being 7.9 per 100,000, or n=251 opioid-related deaths in 2018 (Figure 1).

Natural/semi-synthetic opioids, such as hydrocodone, morphine, oxycodone, and codeine, are the most common type of opioids found in overdose cases until 2018. Since 2011 there has been a significant decrease in this group from 191 down to 99 cases in 2018 (Figure 2). Conversely, heroin and synthetic opioids such as fentanyl have increasingly been involved in opioid overdose deaths. Overdose deaths involving heroin significantly increased 143%, from 37 in 2012 up to 90 in 2018. Overdose deaths involving fentanyl and other synthetic opioids other than methadone increased 377% between 2011 and 2018. Methadone-related overdose deaths decreased 61% from 46 in 2011 to 18 in 2018.

Heroin, hydrocodone, morphine, oxycodone, and fentanyl are the most common opioids found among opioid overdose deaths (Figure 3). Heroin was found in 29% of overdose deaths followed by hydrocodone (27.8%), morphine (24.1%), oxycodone (20.5%) and fentanyl (14.3%) between 2011 and 2018. However, hydrocodone, morphine and codeine involvement in deaths demonstrated a decreasing trend from 2011 to 2018, while oxycodone involvement remained relatively stable through this time-period. Importantly, the percentage of heroin and fentanyl involved in overdose deaths increases significantly.

Geographically, opioid-related mortality rates decreased between 2016 and 2018 in Orange County as a whole; however, coastal and southern regions of Orange County consistently had higher rates during the 3-year period (Map: Opioid-related Mortality by City).

The peak of opioid-related emergency department (ED) visits (n=2,423; 76.3 per 100,000) and hospitalizations (n=1,195; 37.6 per 100,000) also occurred in 2016 (Figure 4). The overall rate of ED visits has increased by 178% from 23.3 per 100,000 in 2005 up to 64.8 per 100,000 in 2018. The rate of hospitalizations also increased by 48% from 2005 to 2018 (21.1 vs. 31.3 per 100,000). Similar to overdose deaths, opioid-related ED visits and hospitalizations have recently seen a decreasing trend after 2016. 

Opioid abuse/dependence are the most common types of opioid-related diagnoses found in ED visits and the rate has increased 142% between 2011 and 2018 (13.0 vs 31.5 per 100,000; Figure 5). The rate of heroin poisoning cases more than doubled, from 7.9 per 100,000 in 2011 to 18.2 per 100,000 in 2018. Conversely, natural/semi-synthetic opioid poisoning, opium poisoning, and methadone poisoning diagnoses have decreased between 2011 and 2018. 

Overall opioid-related ED Visits decreased between 2016 and 2018. However, residents in areas of Huntington Beach, Costa Mesa, Laguna Beach, Dana Point, San Juan Capistrano, and San Clemente had higher rates during the same 3-year time frame (Map: Opioid-related ED Visits by Zip Code). Opioid prescription and opioid-related ED visit rates are significantly correlated (r=0.61, p< 0.01) – ZIP codes with higher levels of prescriptions also tended to have more opioid-related ED visits.

There are approximately 1.6 million opioid prescriptions dispensed annually in Orange County (Figure 6). 2016 marks the highest rate and number of opioid prescriptions dispensed (n=1,762,033, 555.7 per 1,000). A decreasing trend is seen onward from 2016 with an 18% drop in 2018 (n=1,451,745, 455.7 per 1,000).

Geographically, opioid prescription rates have decreased in most areas of Orange County (Map: Opioid Prescriptions by Zip Code). High rate areas in Seal Beach, Newport Beach, and Dana Point in 2016 have demonstrated significant drops; however, Laguna Woods has been consistently high between 2016 and 2018.

To gauge potential abuse and overdose of the amount of opioid being prescribed, a conversion to morphine milligram equivalent (MME) is calculated to standardize the dosage among different opioid prescriptions. The MME indicates the amount of morphine an opioid dose is equal to when prescribed. Patients prescribed higher opioid dosages are at higher risk of overdose death.

In 2016, various regions in Orange County exhibited high MME per resident (Map: Morphine Milligram Equivalent by Zip Code). Coastal, southern, and an area in Fullerton saw high MME rates in 2017. A decline in MME rates was seen in 2018; however, Laguna Woods and areas of Newport Beach and Dana Point continue to have high MME rates.

Overall rates for opioid-related mortality, morbidity, and prescriptions in Orange County were highest in 2016 but are currently demonstrating a downward trend. Increasing fentanyl and heroin trends are cautious and ongoing surveillance is needed to determine if these trends will continue to rise in the future. Southern and coastal regions have higher mortality and morbidity rates relative to other areas of the county; however, mortality rates in these regions are declining over time. Opioid prescription and morphine milligram equivalent (MME) rates have also declined significantly since 2016 indicating prescribing patterns are improving.

Definitions

Natural/Semi-Synthetic Opioids: Includes codeine, morphine, hydrocodone, oxycodone, hydromorphone, oxymorphone, buprenorphine, dihydrocodeine, methorphan, noroxycodone and dilaudid.

Synthetic opioids other than methadone: Includes fentanyl, meperidine, tramadol, tapentadol, propoxyphene, norpropoxyphene, normeperidine and mitragynin.

Data

The data used in this brief were obtained from the California Comprehensive Death File (CCDF) via California Department of Public Health and matched to Orange County Sheriff-Coroner cases. Emergency department (ED) and patient discharge/hospitalization (PD) data were obtained from California's Office of Statewide Health Planning and Development (OSHPD). These datasets contain individual records that include demographic information, drug-types, circumstances, diagnoses, and cause of death information for Orange County residents. The CCDF contains multiple causes of death information and identified opioid-related overdoses with the following ICD-10 codes: T40.0 (opium), T40.1 (heroin), T40.2 (natural and semisynthetic opioids), T40.3 (methadone), T40.4 (synthetic opioids, other than methadone), and T40.6 (other and unspecified narcotics). The Sheriff-Coroner Data were case-matched to the CCDF dataset and contains specific opioid types found prior to death via drug testing conducted by the Sheriff-Coroner.

Controlled Substance Utilized Review and Evaluation System (CURES) data from the State of California Department of Justice was used to identify opioid prescription patterns among Orange County residents. The CURES data is de-identified and contains variables such as patient’s county, gender, birth year, prescriber’s county, pharmacy’s county, national drug code, drug name, drug strength, drug quantity, and drug days supply.