Burden of Alcohol Abuse or Dependence Among Long-Term Opioid Users with Chronic Noncancer Pain.

BACKGROUND

Substance abuse disorders among chronic noncancer pain (CNCP) patients add to the clinical challenges and economic burden of caring for such patients. Despite potential risks, some CNCP patients with a history of alcohol abuse or dependence (AAD) and pain that is refractory to nonopioid treatment options may still need opioids for pain management. However, there is a lack of data on adverse outcomes in long-term opioid users with CNCP and a history of substance abuse or AAD disorders.

OBJECTIVE

To compare adverse outcomes and all-cause health care costs among CNCP patients on long-term opioid treatment with and without a previous diagnosis of AAD.

METHODS

Using MarketScan claims databases (2006-2012), CNCP patients with ≥ 90 days of opioid supply after CNCP diagnosis and continuous enrollment 12 months before CNCP diagnosis (baseline period) and 12 months after opioid start (post-index period) were identified. AAD was defined by diagnosis codes at any time before opioid initiation. Outcomes included opioid overdose, accident, and injury episodes identified by ICD-9-CM diagnoses codes. T-tests and Mann-Whitney tests compared continuous measures, and chi-square and Fisher's exact tests compared categorical measures between those with and without AAD. Multivariable analyses for outcomes were conducted, adjusting for baseline differences between cohorts.

RESULTS

Of 21,203 CNCP patients with long-term opioid treatment, 750 (3.5%) had an AAD diagnosis before opioid initiation. AAD patients were significantly younger (48.4 [SD ± 11.4] years vs. 52.8 [SD ± 14.8] years), less likely to be enrolled in Medicare (17% commercial vs. 4% Medicare), and more likely to be male (67% vs. 48%; all P < 0.001). There were no differences in type or number of CNCP diagnoses or Charlson Comorbidity Index (CCI) scores. Patients with AAD had significantly higher rates of depression and anxiety diagnoses, antidepressant and benzodiazepine use, and drug abuse/dependence diagnoses in the baseline period. Twelvemonth post-index rates of opioid overdose (1.2% vs. 0.2%), accident (7.3% vs. 2.8%), and injury (46.1% vs. 36.8%) were greater in the AAD cohort (all P < 0.001). The differences were nonsignificant for accidents in multivariable analyses. While mean prescription costs were similar ($3,562 vs. $3,312; P = 0.212), AAD patients had significantly higher mean all-cause medical costs ($28,429 vs. $22,082; P < 0.001) and significantly higher all-cause total health care costs ($31,991 vs. $25,395; P < 0.001). The cost differences remained significant in multivariable analyses.

CONCLUSIONS

In the first year after long-term opioid initiation, CNCP patients with a previous AAD diagnosis had 5 times the rate of opioid overdose, 2.3 times the rate of accidents, 1.2 times the rate of injury, and higher all-cause health care costs compared with those not diagnosed with AAD.

DISCLOSURES

Funding for this research study and resultant publication was provided by Teva Global Health Economics and Outcomes Research, which fully reviewed the manuscript. Gajria and Yeung are employees of Teva Pharmaceuticals. White was an employee of Teva Pharmaceuticals at the time this research was conducted. Blumberg and Coutinho are employees of Xcenda, which received research funding from Teva Pharmaceuticals for the conduct of this study and for the preparation of this manuscript. Katz has received research funding and consulting fees from Teva Pharmaceuticals unrelated to this study. Study concept and design were contributed by Katz, White, and Blumberg, along with Coutinho and Yeung. Coutinho took the lead in data collection, assisted by the other authors. Data interpretation was performed by Blumberg, Katz, and Gajria, along with the other authors. The manuscript was written by Gajria, Yeung, Coutinho, and Blumberg, along with Katz and White, and revised by Gajria, Blumberg, Katz, and Coutinho, along with Yeung and White.