Article, Emergency Medicine

Racial and ethnic disparities in the management of acute pain in US emergency departments: Meta-analysis and systematic review

a b s t r a c t

Objective: This review aims to quantify the effect of minority status on analgesia use for acute pain management in US Emergency Department (ED) settings.

Methods: We used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) method- ology to perform a review of studies from 1990 to 2018 comparing racial and ethnic differences in the adminis- tration of analgesia for acute pain. Studies were included if they measurED analgesia use in white patients compared to a racial minority in the ED and studies were excluded if they focused primarily on chronic pain, case reports and survey studies. Following data abstraction, a meta-analysis was performed using fixed and random-effect models to determine primary outcome of analgesia administration stratified by racial and ethnic classification.

Results: 763 articles were screened for eligibility and fourteen studies met inclusion criteria for qualitative syn-

thesis. The total study population included 7070 non-Hispanic White patients, 1538 Hispanic, 3125 Black, and 50.3% female. black patients were less likely than white to receive analgesia for acute pain: OR 0.60 [95%-CI, 0.43-0.83, random effects model]. Hispanics were also less likely to receive analgesia: OR 0.75 [95%-CI, 0.52-1.09].

Conclusion: This study demonstrates the presence of racial disparities in analgesia use for the management of acute pain in US EDs. Further research is needed to examine patient reported outcomes in addition to the pres- ence of disparities in other groups besides Black and Hispanic. Trial registration: Registration number CRD42018104697 in PROSPERO.

(C) 2019

Introduction

ED provision of care is weighted toward traditionally vulnerable populations such as racial and Ethnic minorities [1]. Administering anal- gesia for painful illness and injury is critical to many clinical encounters in the ED and multiple prior studies have shown that race and ethnicity may be associated with adequacy of analgesia administered [2-10]. Prior systematic reviews have examined the provision of analgesia in ethnic minorities in chronic cancer pain, post-operative pain, and palli- ative pain [11-13]. This is the first systematic review to address the as- sociation of relative analgesic administration to racial and ethnic minorities with acute pain in the ED.

* Corresponding author at: 2120 L Street NW, Suite 450, Washington, DC 20037, United States of America.

E-mail addresses: [email protected] (P. Lee), [email protected] (M. Le Saux), [email protected] (M. Goyal), [email protected] (C. Chen), [email protected] (Y. Ma), [email protected] (A.C. Meltzer).

Methods

We used the PRISMA (Preferred Reporting Items for Systematic Re- views and Meta-Analyses) methodology to perform this systematic re- view [14]. With librarian assistance, we used electronic search engine centered on the following key terms: minority, minorities, race, racial, ethnic, ethnicity, pain treatment, pain management, pain medication, analgesia, acute, and acute services (full search strategy available in the Appendix section). Inclusion criteria include research conducted be- tween 1990 and 2018, US-based ED or urgent care settings, adult pa- tients, and studies that compared white patients to an ethnic or racial minority for acute pain. Exclusion criteria included research that fo- cused primarily on chronic pain, chest pain, post-operative pain, case re- ports or survey studies (Table 1). The title and abstract of all identified studies were screened for relevance to study aims. Abstracts were then screened to identify inclusion criteria. Finally, the full text of the re- maining potentially eligible articles were reviewed and appraised in

https://doi.org/10.1016/j.ajem.2019.06.014

0735-6757/(C) 2019

Table 1

Inclusion and exclusion criteria.

Inclusion Exclusion

  • United States based Emergency Departments or Acute care settings o Non-United States studies
  • United States studies in English (conducted in the US) o Published before 1990
  • Published between 1990 and June 2018 o Single race studies or comparison with minority groups only
  • At least one aim or analysis comparing Administration of analgesia for pain between a racial or ethnic minority and majority (white group)
  • Children
    • Adults o Non-analgesic pain treatment
    • Analgesic pain treatment o Literature reviews, systematic reviews, surveys, database studies, vignettes, experimental studies
    • Primary studies, electronic medical records, chart reviews o Pain experiences without treatment
    • Acute pain o Studies limited to chronic pain or condition
      • Post-op pain
      • Chest pain
      • No match with study goals
      • Eligible, but outcomes do not accumulate across studies or insufficient information to calculate effect size

detail for final selection. Data was abstracted with structured data sheets. Acute pain was categorized by traumatic or non-Traumatic causes and analgesia was categorized by opiate or non-opiate class. We attempted to contact first authors if data were missing in any pub- lished material. For the meta-analysis, we compared the odds for receiv- ing any analgesia between individual ethnic minorities and the index group of Whites. Two independent reviewers were involved in each stage of review and in data selection. Any discrepancies were resolved by consultation with a third reviewer. (See Table 2.)

Study quality

Study quality was assessed per the Downs and Black criteria, which has been used for both randomized and nonrandomized observational studies [11,15]. Individual studies were assessed on a 13-item scale

(Appendix) that analyzed study design, sample size, clarity of reporting, and adjustment of confounding variables. An assignment of high-quality was given if a study fulfilled 76% or more of the criteria, moderate-qual- ity if a study fulfilled 51-75%, and low-quality if a study fulfilled b50%.

Results

Database search by key terms yielded 756 articles, and eleven other potentially relevant articles were identified by reference search of dis- covered articles. Following the removal of duplicates and application of inclusion and exclusion criteria (Table 1), seventeen full-text articles were evaluated. Out of these seventeen full-text articles, fourteen contained information on analgesic prescription patterns (Fig. 1) and thirteen contained quantitative information appropriate to answering the primary objective. Ten of the fourteen studies were retrospective

Table 2

Summary of studies.

Source

Relevant outcome (s)

Racial and ethnic groups

Design

Setting

Pain type

Data period

Study quality

Adjustment for confounders

Bartfield et al. (1997)

Any analgesia

C, NC

P

ED

LBP

1994

L

No statistical adjustment

Bijur et al. (2008)

Bijur et al. (2008)

Any analgesia, opioids

Any analgesia,

AA, H, W

AA, H, W

P

R

ED

ED

LBF

LBF

2002-2006

2000-2002

H

H

Age, sex, education, insurance, base-line

patient-rated pain, hospital, whether accompanied to ED

Age, sex, marital status, insurance, mechanism of

Fuentes et al. (2002)

opioids

Any analgesia

AA, H, AS, W

R

ED

LBF

1998-1999

H

injury, mode of arrival, reduction, fracture type, disposition

Sex, bone fractured, need for reduction

Heins et al. (2006)

Infinger et al. (2014)

Any analgesia, opioids

Any analgesia

B, W, O

B, W, O

R

R

ED

EMS

MSP

PF

2004

2011

M

M

Age, sex, insurance status, chronic pain, trauma, provider training, Provider experience

Age, sex, Pain severity, injury location, distance of

Karpman et al. (1997)

Any analgesia

H, W

R

ED

LBF

1992

M

fall

No statistical adjustment

Miner et al. (2006)

Any analgesia

AA, H, NA, AS, W

P

ED

PRV

2003-2004

M

Age, sex, income, education, occupation, subjective

Minick et al. (2012)

Any analgesia,

B, W, O

R

ED

LBF

2010

M

pain severity, time under pre-hospital care

Age, sex, severity of pain, fracture location

Stover et al. (2006)

opioids

Opioids

H, W, O

P

WC

BP

2002-2003

M

Age, sex, BMI, pain intensity, height, education,

Todd et al. (1990)

Any analgesia

H, W

R

ED

LBF

1990-1991

H

Household income, Tobacco use

Age, sex, insurance status, primary language, type

of fracture, mechanism of injury, occupational

Todd et al. (2000)

Any analgesia,

B, W

R

ED

LBF

1992-1995

H

injury, reduction, time of presentation, total time in ED, admitted

Time since injury, total time in ED, time of

Ware et al. (2012)

opioids

Any analgesia

AA, C

R

ED

LBF

NR

L

presentation, payer status, need for reduction

Age, gender, fracture location, type of analgesia,

Young et al. (2013)

Any analgesia

C, AA, AS, H, O

R

EMS

BTI

2009

H

route of dose, pain instrument used, pain score Age, sex, pain score, prehospital time

Racial and ethnic groups: AA = African American, AS = Asian, B = Black, C = Caucasian, H = Hispanic, NA = Native American, NC = non-Caucasian, O = Other, W = White. Design: P = prospective, R = retrospective. Setting: ED = Emergency Department, EMS = Emergency Medical Services, WC = Worker’s Compensation. Pain type: BP = back pain, BTI = blunt trauma injury, LBF = long bone fracture, LBP = low back pain, MSP = Musculoskeletal pain, PF = post fall pain, PRV = pain related visit. NR = not reported. Study quality: Downs and Black criteria adapted, Low = 0-50%; Medium = 51-75%; High = 76-100% [15].

Fig. 1. PRISMA diagram describing search strategy.

studies and four were prospective. Eleven of the fourteen studies were conducted in a traditional ED while three were conducted in urgent care-like settings. Eight studies examined analgesia use for pain from long bone fractures, two for back pain, and single studies examined an- algesic administration for blunt trauma injury, musculoskeletal pain, post-fall pain, and pain related visits. Five studies also included data on opioid-specific analgesia in addition to total analgesia. One study fo- cused solely on Opioid analgesia and did not report on administration of other analgesia classes. In terms of racial categorization, all fourteen ar- ticles included data from “Whites” (also referred to as “Caucasian” or “non-Hispanic Whites”). Six studies included the terms “non-Cauca- sian” or “Other” when grouping racial and ethnic subgroups.

Black patients were 36% less likely to receive any analgesia com- pared to white patients in the fixed effect model, OR 0.64 [95%-CI: 0.55-0.75] and 40% less likely in the random effects model, OR 0.60 [95%-CI, 0.43-0.83] (Fig. 2A). Hispanic patients were 30% less likely to receive analgesia compared to non-Hispanic White patients in the fixed effects model, OR 0.70 [95%-CI, 0.57-0.87] and 25% less likely with a random effects model, 0.75 [95%-CI, 0.52-1.09] (Fig. 2B). We also analyzed the likelihood of receiving opioid analgesia between Black and White patients and between Hispanic and non-Hispanic White patients (Fig. 3A-B). Black patients were 35% less likely to receive opioids for acute pain in the fixed effects model, OR 0.65 [95%-CI,

0.46-0.91] and 34% less likely to receive opioids in the random effects model, OR 0.66 [95%-CI, 0.42-1.02]. Hispanic patients were 23% less likely to receive opioids in the fixed effects model, OR 0.77 [95%-CI, 0.59-1.01] and 13% less likely in the random effects model, OR 0.87 [95%-CI, 0.51-1.51]. The effect of pain type was also stratified by cate- gory of acute pain: long bone fracture or traumatic pain versus no frac- ture or non-traumatic pain (Fig. 4A-B). In Long-bone fracture or traumatic pain, Black patients were significantly less likely to receive analgesia, OR 0.59 [95%-CI, 0.42-0.82]; in those with no fracture or non-traumatic pain, Black patients were also less likely to receive anal- gesia although the CI was not significant, OR 0.51 [95%-CI, 0.15-1.72]. Although we also ran analysis for Asian and “Other” racial and ethnic categories that yielded decreased odds ratios, the study populations were small and therefore less robust (Fig. 2C-D).

Discussion

This study aimed to synthesize the mixed results of prior ED-based studies to determine if a discrepancy in analgesia use exists for White patients versus Black and Hispanic. Prior small studies on acute pain that have examined the association between race, ethnicity and analge- sia use have produced mixed results. For example, Todd et al. reported that non-Hispanic White patients were twice as likely as Hispanic

patients to receive pain medication for isolated long-bone fractures in the ED [10]. Likewise, another study by Todd on long bone fractures in the ED demonstrated that White patients were more likely than Black patients to receive analgesia despite similar pain complaints [9]. How- ever, five other studies on long bone fractures found no significant asso- ciation between analgesia use and the race or ethnicity of the patients [16-20]. When we analyzed the studies as a function of time, we did not discern a trend that the disparity is getting better or worse. In this meta-analysis of all available literature, analgesia was prescribed less commonly to Black and Hispanic patients treated for acute pain. This difference was most pronounced in the prescription of opioid analgesia for Black patients who sustained a long bone fracture or traumatic pain. The magnitude of analgesia disparity may be underestimated in

Hispanic patients as some studies excluded patients who were non- English speaking.

The reasons for differences in analgesia use are likely to be multifold. Pain is a complex topic that involves biology, culture, and psychology, and may not be adequately described by the commonly used “0 to 10” pain intensity score [20]. It is possible that the disparity reflects cultural differences regarding the perception or communication of pain [13,21]. For example, it has been suggested that some groups in the African American community may place more value on stoicism than on relief of discomfort with reluctance to complain of pain [3,22]. Another study looked at the Mexican American veteran population and how the role of “machismo” influenced the expression and daily experience of pain with the conclusion that strict gender standards and pain

Fig. 2. A. Analgesia: Black and White. B Analgesia: Hispanic and White. C Analgesia: Asian and White. D Analgesia: Other and White.

Fig. 2 (continued).

expression was influenced by their ethnic identity [23]. There was also no evidence to suggest that racial or ethnic minorities requested analge- sia more or less than non-Hispanic white patients. Only one study re- ported rates of opioid request in addition to overall consumption. This study was a prospective cohort study of patients with work-related back injury [6]. It is also possible that the disparities do not exist on an individual doctor-patient level which would suggest individual physi- cian bias but reflect practice differences in EDs as all studies were in urban settings that treat predominately White versus Black or Hispanic patients. Physician provider race may also influence analgesia adminis- tration, but this was reported in only two studies where neither re- ported a relative risk of differential analgesia administration [9,10]. Moreover, the lack of patient-centered outcomes in our analysis regard- ing pain relief means that we must infer that less analgesia equals less pain relief but, in reality, those parameters may not be equivalent. In ad- dition, while relief of pain is a well-established quality measure in med- icine, the use of more opioid analgesia for acute pain may not signal better quality care as many Negative outcomes are associated with opi- oid use [24].

We took several steps to account for the heterogeneity seen in our studies. First, we grouped similar outcomes and analyzed each outcome in the context of defined racial and ethnic groups. Second, we analyzed with a random effects model and a fixed effects model and included a measurement of heterogeneity for each analysis. Third, we limited our review to only primary studies that addressed acute pain in the ED.

Conclusion

This meta-analysis synthesizes all available primary studies on anal- gesia use in the ED broken down by race and ethnicity. In the meta- analysis, we have shown that Black and Hispanic patients are less likely to receive the equivalent analgesia medication as non-Hispanic White patients. In the future, more research is needed to understand dispar- ities of care and institute effective corrective interventions for all US ED patients.

Meetings

  • March 30, 2019 — Lightning Oral Abstract Presentation at Mid- Atlantic Society of Academic Emergency Medicine in Washington, DC.
  • May 16, 2019 — Oral Abstract Presentation at Society of Academic Emergency Medicine 2019 in Las Vegas, NV.

This research was unfunded.

Declaration of Competing Interests

None.

Fig. 3. A. Opioid specific: Black and White. B. Opioid specific: Hispanic and White.

Author contributions

PL and AM contributed to study concept and design, acquisition of the data.

AM, YM, CC and PL contributed to analysis and interpretation of the data.

YM and CC contributed statistical expertise.

PL, ML, RS, MG, CC, YM and ACM contributed to drafting and critical revision of the manuscript.

ACM takes responsibility for the paper as a whole.

Appendix

Search strategy: (TITLE-ABS-KEY (minority) OR TITLE-ABS-KEY (mi- norities) OR TITLE-ABS-KEY (race) OR TITLE-ABS-KEY (racial) OR TITLE- ABS-KEY (ethnic) OR TITLE-ABS-KEY (ethnicity) AND TITLE-ABS-KEY

(pain AND treatment) OR TITLE-ABS-KEY (pain AND management) OR TITLE-ABS-KEY (pain AND medication) OR TITLE-ABS-KEY (analgesia) AND TITLE-ABS-KEY (acute) OR TITLE-ABS-KEY (acute AND services)) AND (PUBYEAR N 1989) AND (EXCLUDE (DOCTYPE, “cp”)) AND (LIMIT-TO (LANGUAGE, “English”))

Downs and Black checklist adaptation for quality assessment:

What was the study design? 1 point for prospective. 0 for retrospective.
  • Is the hypothesis/aim/objective of the study clearly described? 1 point for yes. 0 for no.
  • Are the main outcomes to be measured clearly described in the In- troduction or Methods section? If the main outcomes are first men- tioned in the Results section, the question should be answered no. 1 point for yes. 0 for no.
  • Is the racial/ethnic group breakdown of the subjects included in the
  • study clearly described? 1 point for yes. 0 for no.

    Are the distributions of principal confounders in each group of sub- jects to be compared clearly described? A list of principal con- founders is provided. 1 point for yes. 0 for no.
  • Are the main findings of the effect of race/ethnicity on the pain Treatment outcome clearly described? 1 point for yes. 0 for no.
  • Have actual probability values been reported (e.g., 0.035 rather than b0.05) for the main outcomes except where the probability value is b0.001? 1 point for yes. 0 for no.
  • Were the subjects asked to participate in the study representative of the entire population from which they were recruited? The study must identify the source population for patients and describe how the patients were selected. Patients would be representative if they comprised the entire source population, an unselected sample of consecutive patients, or a random sample. 1 point for yes. 0 for no. 0 for unable to determine.
  • Were the statistical tests used to assess the main outcomes appro- priate? The statistical techniques used must be appropriate to the data. For example non-parametric methods should be used for small sample sizes. Where little statistical analysis has been under- taken but where there is no evidence of bias, the question should be answered yes. If the distribution of the data (normal or not) is not
  • Fig. 4. A. Analgesia: Black and White. B. Analgesia: Hispanic and White.

    described it must be assumed that the estimates used were appro- priate and the question should be answered yes. 1 point for yes. 0 for no. 0 for unable to determine.

    How was race/ethnicity used in the analysis? 1 point for anal- ysis presented by subgroups. 0 for lumping of Racial/ethnic groups.
  • Were the racial/ethnic subgroups recruited from the same popula- tion? For example, patients for all comparison groups should be se- lected from the same hospital (unmeasured characteristics or the setting related to variables). 1 point for yes. 0 for no. 0 for unable to determine.
  • Was there adequate adjustment for confounding in the analyses from which the main findings were drawn? (Inclusion of theoreti- cally significant and statistically significant confounders i.e., those found significant in preliminary analysis). 1 point for yes. 0 for no. 0 for unable to determine.
  • Were the procedures to estimate sample size described? If power analysis provided, did study have at least 80% power to detect the differences. 1 point for adequate power. 0 for no. 0 for unable to determine.
  • References

    1. Marcozzi D, Carr B, Liferidge A, Baehr N, Browne B. Trends in the contribution of emergency departments to the provision of hospital-associated health care in the USA. Int J Health Serv 2018;48(2):267-88 Accessed 19 January 2019 https://doi. org/10.1177/0020731417734498.
    2. Green CR, Anderson KO, Baker TA, et al. The unequal burden of pain: confronting ra- cial and Ethnic disparities in pain. Pain Med 2003;4(3):277-94 Accessed 28 June 2018 https://doi.org/10.1046/j.1526-4637.2003.03034.x.
    3. Anderson KO, Green CR, Payne R. Racial and ethnic disparities in pain: causes and consequences of unequal care. J Pain 2009;10(12):1187-204 Accessed 28 June 2018 https://doi.org/10.1016/j.jpain.2009.10.002.
    4. Al-Hashimi M, Scott S, Griffin-Teall N, Thompson J. Influence of ethnicity on the per- ception and treatment of early post-operative pain. Br J Pain 2015;9(3):167-72 Accessed 28 June 2018 https://doi.org/10.1177/2049463714559254.
    5. Infinger AE, Studnek JR. An assessment of pain management among patients pre- senting to emergency medical services after suffering a fall. Prehospital Disaster Med 2014;29(4):344-9 Accessed 28 June 2018 https://doi.org/10.1017/ S1049023X14000594.
    6. Stover BD, Turner JA, Franklin G, et al. Factors associated with early opioid prescrip- tion among workers with low back injuries. J Pain 2006;7(10):718-25 Accessed 28 June 2018 https://doi.org/10.1016/j.jpain.2006.03.004.
    7. Minick P, Clark PC, Dalton JA, Horne E, Greene D, Brown M. Long-bone fracture pain management in the emergency department. J Emerg Nurs 2012;38(3):211-7 Accessed 31 July 2018 https://doi.org/10.1016/j.jen.2010.11.001.
    8. Young MF, Hern HG, Alter HJ, Barger J, Vahidnia F. Racial differences in receiving morphine among prehospital patients with blunt trauma. J Emerg Med 2013;45

      (1):46-52 Accessed 31 July 2018 https://doi.org/10.1016/j.jemermed.2012.07.088.

      Todd KH, Deaton C, D’Adamo AP, Goe L. Ethnicity and analgesic practice. Ann Emerg Med 2000;35(1):11-6 Accessed 31 July 2018 https://doi.org/10.1016/S0196-0644

      (00)70099-0.

      Todd KH, Samaroo N, Hoffman JR. Ethnicity as a risk factor for inadequate emer- gency department analgesia. JAMA 1993;269(12):1537-9 Accessed 31 July 2018 https://doi.org/10.1001/jama.1993.03500120075029.

    9. Meghani SH, Byun E, Gallagher RM. Time to take stock: a meta-analysis and system- atic review of analgesic treatment disparities for pain in the United States. Pain Med (USA) 2012;13(2):150-74 Accessed 31 July 2018 https://doi.org/10.1111/j.1526- 4637.2011.01310.x.
    10. Cintron A, Morrison RS. Pain and ethnicity in the United States: a systematic review. J Palliative Med 2006;9(6):1454-73 Accessed 31 July 2018 https://doi.org/10.1089/ jpm.2006.9.1454.
    11. Booker SQ. African Americans’ perceptions of pain and pain management: a system- atic review. J Transcult Nurs 2016;27(1):73-80 Accessed 31 July 2018 https://doi. org/10.1177/1043659614526250.
    12. Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg 2010;8(5):336-41 Accessed 3 April 2019 https://doi.org/10.1016/j.ijsu.2010.02.007.
    13. Downs SH, Black N. The feasibility of creating a checklist for the assessment of the methodological quality both of randomised and non-randomised studies of health care interventions. J Epidemiol Community Health 1998;52(6):377-84 Accessed 4 August 2018 https://doi.org/10.1136/jech.52.6.377.
    14. Bijur P, Berard A, Nestor J, Calderon Y, Davitt M, Gallagher EJ. No racial or ethnic dis- parity in treatment of long-bone fractures. Am J Emerg Med 2008;26(3):270-4 Accessed 31 July 2018 https://doi.org/10.1016/j.ajem.2007.05.010.
    15. . Bijur P, Berard A, Esses D, Calderon Y, Gallagher EJ. Race, ethnicity, and manage- ment of pain from long-bone fractures: a prospective study of two academic urban emergency departments. Acad Emerg Med. 2008; 15(7): 589-597. Accessed 31 July 2018. doi:https://doi.org/10.1111/j.1553-2712.2008.00149.x.
    16. Fuentes EF, Kohn MA, Neighbor ML. Lack of association between patient ethnicity or race and fracture analgesia. Acad Emerg Med 2002;9(9):910-5 Accessed 31 July 2018 https://doi.org/10.1197/aemj.9.9.910.
    17. Karpman R, Mar ND, Bay C. Analgesia for emergency centers’ orthopaedic patients: does an ethnic bias exist? Clin Orthop Relat Res 1997;334:270-5 [Accessed 30 July 2018].
    18. Ware LJ, Epps CD, Clark J, Chatterjee A. Do ethnic differences still exist in pain assess- ment and treatment in the emergency department? Pain Manage Nurs 2012;13(4): 194-201 Accessed 28 June 2018 https://doi.org/10.1016/j.pmn.2010.06.001.
    19. Campbell CM, Edwards RR, Fillingim RB. Ethnic differences in responses to multiple experimental pain stimuli. Pain 2005;113(1-2):20-6 Accessed 31 July 2018 https:// doi.org/10.1016/j.pain.2004.08.013.
    20. Anderson KO, Richman SP, Hurley J, et al. Cancer pain management among under- served minority outpatients: perceived needs and barriers to optimal control. Can- cer. 2002; 94(8): 2295-2304. Accessed 6 December 2018. doi:https://doi.org/10. 1002/cncr.10414.
    21. Cancio R. Pain and masculinity: a cohort comparison between Mexican American Vietnam and Post-9/11 combat veterans. Men Masculin 2018. https://doi.org/10. 1177/1097184X18761779 Accessed 27 May 2019.
    22. Vijay A, Rhee TG, Ross JS. U.S. prescribing trends of fentanyl, opioids, and other pain medications in outpatient and emergency department visits from 2006 to 2015. Prev Med 2019;123:123-9 Accessed 4 April 2019 https://doi.org/10.1016/j.ypmed.

      2019.03.022.

    Leave a Reply

    Your email address will not be published. Required fields are marked *