Study Population 
 
 Using the Centers for Medicare and Medicaid Services carrier files for a 20% random sample of beneficiaries from January 1, 2008, through December 31, 2011, we identified index emergency department visits at acute care hospitals by Medicare beneficiaries.
– Scientists trying to better understand the nation's rising opioid addictions have uncovered an interesting wrinkle: A patient's risk of getting hooked might depend on which ER doctor they happen to get. In a New England Journal of Medicine study, researchers found that patients whose ER doctors are more likely to prescribe opioids are more likely to develop an addiction compared to the patients of ER doctors who prescribe less frequently. It may sound like an obvious chain of events, but it remains unclear why two patients given the same opioid prescription after similar complaints have different addiction risks depending on their ER doc. The takeaway is "not that high-intensity prescribers are necessarily irresponsible in prescribing opioids to certain patients," the lead author tells the New York Times. But "their patients have worse outcomes that we weren’t aware of before." After tracking 375,000 Medicare patients in ERs between 2008 and 2011, researchers found that one in every 48 patients prescribed opioids ends up using them long-term, or more than half a year. But when comparing "high-intensity" prescribing docs (who gave opioids to one in four patients) to "low-intensity" prescribers (one in 14), patients of the first group had a 30% greater risk of turning into long-time users. It may be a simple numbers game, as observed in a post at Pacific Standard: "The more prescriptions doctors give out, the more likely they'll end up handing a script to someone who will have a serious problem later." But one doctor sees a larger issue: Among ER doctors, there's no consensus "about when to prescribe opioids and what dose to give." (This is how long it takes to become dependent.)