Factors Influencing Long-Term Opioid Use Among Opioid Naive Patients: An Examination of Initial Prescription Characteristics and Pain Etiologies

The relationships between the initial opioid prescription characteristics and pain etiology with the probability of opioid discontinuation were explored in this retrospective cohort study using health insurance claims data from a nationally representative database of commercially insured patients in the United States. We identified 1,353,902 persons aged 14 years and older with no history of cancer or substance abuse, with new opioid use episodes and categorized them into 11 mutually exclusive pain etiologies. Cox proportional hazards models were estimated to identify factors associated with time to opioid discontinuation. After accounting for losses to follow-up, the probability of continued opioid use at 1 year was 5.3% across all subjects. Patients with chronic pain had the highest probability for continued opioid use followed by patients with inpatient admissions. Patients prescribed doses morphine milligram equivalents (hazard ratio [HR] = .91; 95% confidence interval [CI], .91.92), initiated with tramadol (HR = .89; 95% CI, .89.90) or long-acting opioids (HR = .79; 95% CI, .77.82) were less likely to discontinue opioids. Increasing days' supply of the first prescription was consistently associated with a lower likelihood of opioid discontinuation (HRs, CIs: 3-4 days' supply = .70, .70-.71; 5-7 days' supply = .48,.47-.48; 8-10 days' supply = .37, .37-.38; 11-14 days' supply = .32, .31-.33; 15-21 days' supply = .29, .28-.29; >= 22 days supplied = .20, .19-.20). The direction of this relationship was consistent across all pain etiologies. Clinicians should initiate patients with the lowest supply of opioids to mitigate unintentional long-term opioid use. Perspective: This study shows that characteristics of the first opioid prescription, particularly duration of the prescription, are significant predictors of continued opioid use irrespective of the indication for an opioid prescription. These data should encourage prescribers to initiate patients using the minimum effective opioid dose and duration to reduce unintended long-term use and could motivate policies that restrict the initial supply of opioids. (C) 2017 by the American Pain Society