Racial Differences in Primary Care Opioid Risk Reduction Strategies

INTRODUCTION

Studies in varied health care settings including primary care practices report that physicians are less likely to prescribe opioid analgesics to treat pain in black compared with white patients, even after adjusting for severity of illness and other clinically relevant factors.^1–4 This inequity in pain management is not based on evidence of greater opioid misuse among black patients; in fact, studies find that whites are more likely than blacks to misuse prescription opioids^5,6 or that race is not a factor.^7,8 Researchers hypothesize that differential opioid prescribing may reflect a lack of physician training and confidence in managing pain in minority groups as well as limited evidence-based protocols for managing pain with opioids, leading physicians to rely on stereotypes to guide decision making.^9,10

Most chronic pain management occurs in primary care settings, where physicians must decide whether to prescribe opioids and, if these medications are prescribed, how to monitor patients for misuse. Given the increasing rates of opioid misuse and diversion, and their serious consequences including overdose and death,^11–13 as well as physicians’ inability to judge risk of opioid misuse accurately,¹⁴ it is important for all patients taking opioids to be monitored for safety. Recently, the American Academy of Pain Medicine and the American Pain Society¹⁵ and other experts¹⁶ have recommended that physicians should implement a structured treatment monitoring plan to reduce the risks associated with long-term opioid use. Few primary care physicians appear to have adopted recommended strategies, however.^17–19

In light of reports of racial disparities in physician management of pain with more restrictive use of opioids for black compared with white patients,^1–4 we hypothesized that racial differences exist in the opioid risk reduction strategies used for patients prescribed opioids long term for chronic pain. Specifically, we hypothesized that black patients would be more likely than white patients to receive urine drug testing, regular office visits, and restricted early refills.

METHODS

RESULTS

The 8 primary care practices had a total of 4,057 patients who had 3 or more opioid prescriptions, of whom 1,612 (40%) met our inclusion criteria ( Figure 1⇓). Most patients were excluded because they had not been prescribed opioids long term (ie, had <3 opioid prescriptions at least 21 days apart within 6 months).

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Figure 1.

Patient flow diagram

In each practice, a median of 24 physicians (interquartile range, 6–47) treated at least 1 study patient. Among these physicians, the median number of study patients treated was 2 (interquartile range, 1–8) with a maximum of 163. In the final study cohort, 8.0% of patients received urine drug testing, 49.8% had regular office visits, and 76.6% had restricted early refills.

Nearly two-thirds of the 1,612 study patients were black, and black patients were more likely to receive each opioid risk reduction strategy when compared with white patients (Table 1⇓). Black patients were more likely than white patients to be female and to live in neighborhoods having a low-income zip code. In regard to factors associated with greater risk of misuse, black patients were more likely to have diagnosed problem substance use and tobacco use, but were not more likely to have a diagnosed mental health disorder. The pain-related conditions osteoarthritis and lumbago were more common in blacks than in whites. In addition, black patients had more medical comorbidities.

The mean duration of opioid treatment in the cohort was nearly 2 years and did not differ by race (Table 1⇑). Blacks had more primary care visits but poorer adherence to scheduled appointments. The 2 practices excluded from the urine drug testing models had significantly smaller proportions of black patients when compared with the remainder of the cohort (6.6% vs 73.5%; P <.001).

Table 2⇓ displays the effect of additively adjusting for sets of patient, clinical, and health care variables on the odds of black patients receiving opioid risk reduction strategies when compared with their white counterparts. The far left column shows the unadjusted association of black race with each strategy. Subsequent columns moving to the right show the change in this association with sequential addition of each set of variables to the model. The far right column shows the odds ratios in the fully adjusted model.

In the unadjusted model, black patients were 1.63 times more likely to receive urine drug tests; however, after adjustment for clustering of patients within physicians, the odds ratio was no longer significant (Table 2⇑). After adjustment for all sets of covariates, the odds of urine drug testing for blacks vs whites remained nonsignificant. The adjusted odds of regular office visits were 2.03-fold greater for black vs white patients and did not diminish with adjustment for clustering of patients within physician. The association of black race with regular office visits was progressively attenuated by adding patient, clinical, and health care factors, but the odds of having regular office visits were still 51% higher for black vs white patients in the fully adjusted model. Similarly, the unadjusted association of black race with restricted early refills was significant, with an odds ratio of 1.48. In the fully adjusted model, black race remained significantly associated with 1.55-fold higher odds of restricted early refills.

DISCUSSION

In this large cohort of primary care patients treated for an average of 2 years with opioid analgesics for chronic noncancer pain, black patients were significantly more likely to receive recommended opioid risk reduction strategies than white patients. The adjusted odds of receiving regular office visits and restricted early opioid refills remained increased for black vs white patients after adjustment for diverse patient and health care factors. Approximately 10% of black patients received urine drug testing compared with only 4% of their white counterparts; after adjustment, the odds were still higher for black patients but no longer significantly so. Use of the other 2 risk reduction strategies was also low, with only one-half of the cohort receiving regular office visits and roughly 25% prescribed multiple early opioid refills. This poor performance of long-term opioid treatment monitoring supports widespread calls for improved quality of care to promote safe prescribing of these potentially dangerous medications.²⁶

To our knowledge, this is the first study to examine racial differences in the use of risk reduction strategies for patients treated long term with opioids for chronic noncancer pain. Our novel findings extend those of several related studies. For example, Kunins and colleagues²⁷ found pregnant black women were 1.5 times more likely to undergo urine screening for illicit drug use at prenatal visits than white women, but race was not associated with a positive test result. Our results also complement studies reporting that physicians underestimate the severity of pain in black patients²⁸ and prescribe opioids for pain more commonly to white than to black patients.^29–31 Taken together, these data indicate physicians are more cautious about initiating opioid therapy in black patients and, once the medication is started, monitor black patients more closely than whites.

On the other hand, our finding that black patients on chronic opioid therapy were seen in the office more regularly than white patients contrasts with findings of numerous studies reporting that black persons are less likely to use primary care services.^32–34 Lower use of health care has been attributed in part to black patients’ increased mistrust of clinicians and health care systems.³⁵ We can only speculate as to why black patients were seen more regularly than white patients in our study. First, black patients had a greater number of medical comorbidities, which might have prompted more frequent monitoring visits. Second, black patients in our study population were more likely than white patients to have Medicaid insurance, so they might have had a lower or no copayment for visits. Copayments might have presented a greater barrier to frequent visits for white patients, although this seems unlikely given that white patients came from more affluent neighborhoods. Finally, the higher frequency of visits by black patients may reflect greater physician concern about the need to monitor for misuse or may reflect undertreatment of pain³⁶ so that black patients had to return frequently to modify opioid medications.

Our findings suggest a “reverse disparity”³⁷ in the use of these opioid monitoring strategies, whereby traditionally vulnerable groups receive care more consistent with expert recommendations and guidelines. In fact, our results raise the concern that physicians are inappropriately lax in monitoring white patients, who received lower quality of care in regard to these monitoring outcomes. This laxity contradicts evidence that the risk of prescription drug abuse is greater in whites than in other racial/ethnic groups.^5,6

In our cohort, the association of race with urine drug testing was attenuated after adjustment for clustering within physician, suggesting some physicians may have contributed to this disparity more than others. This was the only outcome, however, for which accounting for clustering of patients within physicians diminished the association of race with the outcome. The monitoring practices of the clinician who had 163 patients on opioids long term were similar to the study averages and displayed no difference in monitoring between black and white patients; thus, excluding this high-volume prescriber’s patients would not have changed our conclusions. Future studies should examine the role of variation in the monitoring practices of individual clinicians in contributing to these inequitable practices in monitoring persons on opioid analgesics.

Although we could not investigate the underlying causes for the across-the-board low rates of implementation of risk reduction strategies, lack of physician training, time, and other practice resources are likely to be major barriers. Another factor may be the dearth of evidence demonstrating the effectiveness of risk reduction strategies in improving misuse outcomes.³⁸ With emerging evidence of an increased overdose risk with higher opioid dosages,³⁹ development of safety-driven treatment and monitoring algorithms becomes even more imperative. Systems-based, safety-enhancing approaches, common in the use of coumadin⁴⁰ and insulin,⁴¹ and emerging with opioids,⁴² are needed to improve the overall use of risk reduction strategies and reduce racial differences in monitoring. Indeed, several centers are pilot testing novel approaches such as use of automated monitoring reminders in the medical record,⁴³ medication monitoring programs staffed by midlevel clinicians within primary care clinics,⁴² and multidisciplinary, disease management clinics where monitoring protocols are standardized.⁴⁴

We acknowledge limitations to our study. First, in this observational study, our findings cannot demonstrate causality; however, we were able to control for potential confounding variables, most notably diagnosed substance abuse and mental health disorders, which are associated with an increased risk of misuse. We relied on coded diagnoses to identify comorbidities including substance use disorders, and we may have missed clinical conditions or behaviors that would increase the need to monitor for misuse, or other unmeasured confounders. It is possible that this misclassification was differential, that is, that clinicians were more likely to code substance use disorder for black than white patients, which would bias results toward the null and attenuate the difference in models adjusting for substance use disorders. Second, despite our relatively large cohort, the low prevalence of urine drug testing limited our power to find a significant association. Furthermore, we removed 2 practices from urine drug testing models because they had little or no urine testing; these practices had predominantly white patients, so excluding them may have led to an underestimation of race’s association with urine drug testing. Third, our cohort came from practices in a single, urban, university-affiliated health system, and the findings may therefore not be generalizable to other settings. Fourth, we did not evaluate the dose of opioids prescribed; however, standard of care is that all patients on long-term opioid therapy need to be monitored, regardless of dose. Last, we examined outcomes supported by consensus guidelines and assessable using the electronic health record. We could not ascertain other monitoring practices, such as use of treatment agreements, querying prescription-monitoring databases, and performing pill counts.

Many experts in the field of pain management advocate for a “universal precautions” approach to risk reduction for patients prescribed opioids for chronic noncancer pain.⁴⁵ Our findings show that real-world clinical practice falls far short of this ideal. This evidence of racial differences in the management chronic noncancer pain should stimulate clinical and educational initiatives to ensure all patients are appropriately monitored. Further, physicians should recognize that patient race should not affect their use of their monitoring strategies. Outcomes research is also necessary to determine whether systems-based approaches with standardized monitoring strategies ameliorate these differences and improve overall monitoring rates.