Comparison of Opioid Prescribing Patterns in the United States and Japan: Primary Care Physicians' Attitudes and Perceptions

Discussion

Few studies have compared beliefs about and attitudes toward opioid prescribing among physicians from countries with sharply contrasting rates of opioid use. It seems that US respondents consider opioids to be the standard of care for both acute and chronic pain more often than their Japanese counterparts. For acute pain in particular, US respondents were more likely than those in Japan to see opioid treatment as both medically indicated and the standard of care.

Part of the international difference is likely related to different health care systems. Japan has a national insurance system, and indications for each medication are strictly followed because insurance plans will not provide coverage otherwise. For example, insurance covers the use of oxycodone only for cancer pain, so it cannot be prescribed for other types of pain. In addition, a tramadol-acetaminophen combination is covered only for noncancer pain and tooth extraction. While codeine, morphine, fentanyl patches, and buprenorphine are covered for both cancer and noncancer pain,¹⁴ physician prescribing for chronic noncancer pain must meet several criteria¹⁵:

1. The physician must have completed lengthy E-learning modules for each specific opioid.

2. Both physician and patient must sign a contractual agreement upon initiating opioid treatment.

3. The patient must be taking nonopioid analgesics before opioids are initiated.

4. The patient must undergo trial use of a challenge opioid to ensure effectiveness before advancing to chronic use.

It is burdensome to store opioids in clinics and pharmacies because Japan has strict storage rules under the Narcotics and Psychotropic Control Law. This, combined with the rare use of opioids, means that many clinics and pharmacies choose not to stock them at all. Driving is strictly prohibited while under the influence of opioids under Japan's Road Traffic Act. Given the current epidemic of opioid misuse and overuse in the United States, such regulations may suggest useful strategies.¹⁶ Another factor is that, in Japan, opioids are frowned on both culturally and socially. Chronic opioid use is viewed as a criminal act by some.¹⁷ Furthermore, Japanese patients may be less likely to complain about pain because of strong cultural mores regarding self-attention—a dynamic far less pervasive in the United States.^18⇓–20 Ironically, however, benzodiazepines are more frequently prescribed in Japan than in any other country.^21,22

While reporting lower overall opioid use, Japanese respondents were more likely than US respondents to suggest that opioids are indicated for chronic pain. They were also more likely than US respondents to believe opioids are underused. US respondents seemed to have mixed views on prescribing opioids for chronic pain. Though only 58.7% of US respondents believed that opioids are indicated for chronic pain, 75.6% indicated that they have prescribed opioids in a chronic pain scenario. This may be the result of awareness by US clinicians of controversy regarding the use of opioids for chronic pain and growing concerns about their efficacy and safety in this setting. These concerns may result in uncertainty regarding optimal opioid prescribing.

Despite system differences, respondents in both the United States and Japan seemed eager to respond to patient requests for pain relief. Respondents in both countries indicated that patient expectations and satisfaction influenced opioid prescribing, especially for chronic pain. Patient satisfaction is a pillar of patient-centered care, and patient satisfaction surveys can be a driving force behind treatment patterns.²³ However, patient dissatisfaction may not always reflect lower-quality care, especially regarding opioid prescribing.²³ Educating the public about acute and chronic pain management and increasing awareness of the serious side effects of long-term opioid therapy may be important priorities. Patients and clinicians should be aware that alternatives such as physical therapy, cognitive-behavioral therapy, and lifestyle modification can be effective for chronic pain.^24,25

Less enthusiasm among Japanese prescribers for treating acute pain with opioids may lead to lower initial opioid exposure and thereby contribute to lower rates of long-term use or misuse. Other investigators are exploring strategies that minimize opioid use for acute pain (after surgery) while maintaining good pain control.²⁶ A new guideline from the Centers for Disease Control and Prevention notes that long-term opioid use often begins with treatment of acute pain.²⁷ Thus, there may be value in greater attention to and better guidelines for optimal opioid prescribing in acute pain.

Limitations of our study include a relatively small sample size, limitation to only one US state (Oregon), focus on a single specialty (Family Medicine), and a relatively low survey response rate. These may limit the generalizability of our results. Unfortunately, we were unable to increase the sample size or response rates (eg, with incentives) because of resource constraints. However, the key findings in our study are congruent with known differences in prescribing rates between the United States and Japan.⁸ Physician survey responses generally tend to be low, averaging only 50% even under ideal conditions.²⁸

The survey design also had limitations. We were unable to conduct conventional psychometric testing because of limited resources, which were devoted to pilot testing, translation, and back translation. We specified the setting in the survey questionnaire as “clinical outpatient,” which may have been interpreted variously to refer to a clinic, an urgent care facility, or even an emergency setting; varying interpretations could have affected responses. Our questions on the frequency of opioid use did not quantify the frequency, though most clinicians could only intuitively estimate their frequency of prescribing in any event.

Our findings may contribute to developing more effective US guidelines and policies on opioid use, especially for acute pain. Conversely, Japanese physicians may want to heed caution from the experiences of their counterparts in the United States, where overdose rates and addiction treatment have increased substantially in parallel with increased opioid prescribing.