High opioid doses, concurrent sedative use are key factors for overdose risk in Medicaid recipients

Among Medicaid recipients taking prescription opioids, high opioid doses and concurrent treatment with benzodiazepine sedatives are among the key, potentially modifiable risk factors for fatal overdose, reports a study in the August issue of Medical Care. The journal is published in the Lippincott portfolio by Wolters Kluwer.

"Prescribers and state agencies should be aware of these addressable patient-level factors among the Medicaid population," according to the new research, led by Timothy T. Pham, PharmD, PhD, of University of Oklahoma College of Pharmacy, Oklahoma City. "Targeting these factors with appropriate policy interventions and education may prevent future deaths."

Clinical Factors and Medications Contribute to Opioid Overdose Risk in Medicaid Patients

In a review of Oklahoma Medicaid and Oklahoma State Department of Health data from 2011 to 2016, the researchers identified 639 Medicaid members who died of an unintentional prescription opioid overdose. Of these, 321 patients had at least one Medicaid-covered opioid prescription in the year before death. The average age was 44.5 years; 64 percent of the patients were women and 81 percent were white.

These cases of overdose death were matched to 963 living Medicaid recipients with similar characteristics, including opioid prescriptions. Demographic factors, clinical characteristics, and medical/pharmacy use over the preceding year were analyzed to identify individual-level risk factors for prescription opioid overdose.

Medicaid patients who died of opioid overdose were more likely to have common causes of chronic pain - particularly neck or joint pain and low back pain. Fatal overdose was more likely for patients diagnosed with opioid dependence, as well as in those with other types of drug toxicity. Risk was also increased for individuals with hepatitis, a common complication in people with addiction disorders; and for those with certain psychiatric disorders, particularly bipolar disorder or schizophrenia.

Higher-dose opioid prescriptions were also an important risk factor. For patients in the two highest dose categories, the odds of fatal opioid overdose were three times higher compared to the control group.

Individuals taking benzodiazepines - a widely used class of sedative drugs - were also at increased risk. About 29 percent of patients who died of prescription opioid overdose were taking benzodiazepines at the same time. The odds of death were elevated with as little as one to six days of overlap between opioids and benzodiazepines.

Studies using state-level data have found that the Medicaid population is a high-risk group for death due to unintentional prescription opioid overdose. Information on individual-level risk factors for opioid overdose and death among Medicaid recipients is needed to help in targeting preventive measures.

The new study provides evidence for several categories of risk factors for fatal opioid overdose in Medicaid members, including chronic pain, medical diagnoses associated with addiction, and mental health disorders. "The findings also emphasize potentially problematic opioid exposure including higher daily [doses] and longer durations of opioid/benzodiazepine overlap," Dr. Pham and coauthors write.

The researchers believe their study "may contribute to recommendations for establishing rational opioid dose thresholds and use of benzodiazepines in clinical guidelines and government policies." Other suggestions include the use of prescription drug monitoring programs and care coordination models to bring together the various specialists involved in patient care.

Dr. Pham and coauthors also point out that approximately half of Oklahoma Medicaid patients who died of prescription drug overdose during the study period did not have a covered prescription claim in the year before death. The researchers add: "This finding may represent the reality that some people were not eligible near the time of death, implying that they obtained their prescriptions through other insurance coverage, other forms of payment, or diversion."