Opioid prescribing little affected by state laws: study

State laws to tighten controls on opioid prescribing have raised concerns among some pain experts and patient advocates about these laws’ impact on patients with noncancer chronic pain and increase the use of deadlier synthetic opioids such as fentanyl. But a new study finds these laws have done little to reduce the number of opioid or nonopioid pain treatments doctors prescribe.

The study, published in Annals of Internal Medicine, looked at 13 states that have implemented one of four types of opioid prescribing laws beginning in 2010 while enacting no potentially confounding laws in a four-year period. These prescribing laws include:

• Laws limiting the dose and/or duration of opioid prescriptions,
• “pill mill” laws preventing pain management clinics from issuing opioid prescriptions without medical indication,
• Laws requiring opioid prescribers to check their state’s prescription drug monitoring program (PDMP) before prescribing an opioid, and
• Laws requiring prescribers to enroll in their state’s PDMP

The patient population in the study consisted of about 2 million commercially insured adults diagnosed with low back pain, headache, fibromyalgia, and/or neuropathic pain who were receiving any form of monthly opioid prescription or guideline-concordant nonopioid pain treatment. 

For each of the 13 states, researchers identified a set of “control states,”—states that did not have the same law of interest and had not changed any other opioid prescribing law during the four-year study period. In the two years following implementation, the 13 state laws were each associated with a change of less than one percentage point in the monthly proportion of patients receiving any opioid prescription in both the overall adult and chronic noncancer pain samples compared with the control states.

Similarly, opioid prescribing laws resulted in a change of less than one day’s supply of opioid prescriptions per month for both sample populations, and a change of less than four in the average monthly morphine milligram equivalents prescribed per day per patient.

The proportion of patients with chronic noncancer pain receiving any kind of guideline-concordant nonopioid pain medication or procedure in the 13 states studied changed by less than two percentage points. “Across the 13 states that implemented laws, the change in treatment attributable to the law was consistently small in magnitude and not statistically significant,” the authors write.

The researchers offer several possible explanations for their findings. One is implementation challenges, such as a lack of health information technology capacity, that might prevent the laws from having their intended effect. Another is loopholes in the laws, such as “professional judgment exemptions” that allow clinicians to override limits on an opioid prescription’s dose or duration, or the absence of provisions in the PDMP laws to allow law enforcement to access PDMP data without a warrant, subpoena, or active investigation.

The authors note that while opioid prescribing has declined in recent years, the trend is due more to changes in clinical guidelines, professional norms and other factors than to the effects of state laws.

The study, “Effects of State Opioid Prescribing Laws on Use of Opioid and Other Pain Treatments Among Commercially Insured U.S. Adults,” was published online March 15 at Annals.org.