Global Inequities in Pain Treatment: How Future Research Can Address This Better

Inequities in pain treatment occur globally[6]. Pain Inequities exist between high-income countries and low- and middle-income countries, as well as within countries based on factors such as race, sex, gender, ethnicity, socioeconomic status, and age[5,20,25,32]. Inequities in pain treatment are more salient in lower income countries due to the disproportionate access to and use of established pain treatments and inadequate pain education[7,11]. These barriers to pain care become more complex with consideration of how socioeconomic factors and sociocultural context impact the pain experience[2,18,30,32,35,36] and contribute to individual differences in pain among populations that are highly affected by the burden of pain.

To date, most clinical, basic science and preclinical pain research has also studied pain and pain treatments in male humans and animals until relatively recently[24,28], yet we now know there are significant sex and gender differences in pain[14]. This has all led to challenges in translating research into practice, particularly in underrepresented and historically excluded populations[15], as well as challenges translating research conducted largely in high-income countries into practice in low- and middle-income countries[17,34].  

Examples of Inequities Include:

• Sex and/or gender differences in the experience and treatment of pain and differences in response to treatment, such as to medications, where women are disadvantaged[5]
• Disparities in pain perception, experience, assessment, and treatment based on patients’ race, ethnicity, and/or age[1,2,21]
• Undertreatment of pain of racialized and minoritized people is more common than in Non-Hispanic White people[1,29]
• Inequities in access, attendance, and outcomes at tertiary chronic pain services[22,31]
• Lack of access to essential analgesics, particularly opioids, in low- and middle-income countries that account for 85% of the world’s population[8]. This includes for patients with cancer pain or non-oncological terminal illnesses, end-of-life care, and post cesarean analgesia [19,23,25]
• The excess of available opioids in some higher income countries has negatively influenced opioid access in middle and low-income countries, especially where opioids are not broadly available[23]
• The burden of the disease is higher, and the probability of effective treatment is lower, in middle and low-income countries (up to 34% in the general population, and 62% in women)[14]

What Contributes to Pain Inequities?

• Discrimination and racism influence access and quality of pain care, as well as outcomes [26]
• False beliefs among medical trainees, such as false beliefs among medical trainees that Black people have thicker skin with fewer nerve endings, and feel less pain, which echo narratives used throughout US history as justification for painful abuse during and after slavery[13] 
• Lack of culturally appropriate pain care that respects the diverse needs of patients[9]
• Stigma. Patients are often stigmatized (by health professionals, the general public, or family members) when there is a lack of objective findings or their pain persists despite treatment [33]
• Governmental policies (or lack thereof) and healthcare systems influences on the availability of and accessibility to pain treatments[10]
• Insufficient pain education and training for medical and allied health professions, which is even greater in LMIC countries[7]. This contributes to poor pain service delivery at all levels
• As a result of insufficient training and limited resources and funding in low- and middle-income countries, there is less research being done. For example, in the Clinicaltrials.gov database, of the 22,461 registered “complete” “pain” studies, only 39 were registered in Colombia, 73 in Mexico, and 619 in BrazilData Catalog, worldbank.org (Data Catalog, worldbank.org)

What to do Next to Increase Equity in Pain Research and Care

Things to Consider Moving Forward

To address the global problem of pain inequities, and increase equity in pain care, we must reflect on how power, racist beliefs, and oppression towards members of a minoritized or racialized groups have contributed to inequities in the experience and treatment of pain around the world. Future research should consider or examine how caste systems, classism, colorism, racism, ageism, sexism, stigma, and discrimination and/or biases based on race, ethnicity, color, age, sex, gender, sexual identity, religion, income, geographic region, and disability status contribute to inequities in pain research and treatment. It is also important to examine and overcome biases and inequities that exist regarding research conducted in low- and middle-income countries[12].

Actions we can take:

• Recognize that inequities exist. When ethnic and racial differences in pain treatment are identified, they should be addressed to achieve health equity.
• Make pain research more inclusive by conducting studies that include underserved, diverse populations to help generalize study findings[9].
• Partner with people living with pain in pain research, education, and treatment. Include patient partners from populations that have been historically, socially, or economically excluded, such as minoritized and racialized communities [4,16] (See Partnering with People with Lived Experience in Pain Research Global Year fact sheet).
• Develop culturally appropriate/sensitive pain assessments and treatments in partnership with patients and practitioners to contribute to the successful translation and implementation of the latest evidence-based practices [9,15,37].
• Develop or use existing technology where appropriate and feasible to improve access to pain treatment, especially in remote areas. Include community leaders, health experts, and technology experts in the development and implementation[9].
• Collaborate with local communities to identify and prioritize research, education, treatments, and support that meet their needs[9].
• Use anti-racism, intersectional, and equity-oriented frameworks for pain research[3].
• Build research capacity in low- and middle-income countries.
• Promote and support global collaboration between research groups from high-income, low-income and middle-income countries.
• Promote and support the exchange of short academic visits of professors between high- and low-income countries.
• Facilitate clinical rotations of medical students from low- and middle-income countries to academic centers in high-income countries
• Facilitate contact and collaboration between patient groups in high-income countries and similar groups in low and middle-income countries, such as through IASP’s Global Alliance of Partners for Pain Advocacy (GAPPA)
• Acknowledge and study the impacts of colonization and colonial medicine that are still present in the beliefs, attitudes, policies, and practices of medicine and research today.
• Finally, it is of high priority that high-income countries support low and middle-income countries in achieving these steps, including access to resources, education, and funding

REFERENCE

[1] Anderson KO, Green CR, Payne R. Racial and Ethnic Disparities in Pain: Causes and Consequences of Unequal Care. Journal of Pain 2009;10:1187–1204.

[2] Arthur L, Rolan P. A systematic review of western medicine’s understanding of pain experience, expression, assessment, and management for Australian Aboriginal and Torres Strait Islander Peoples. Pain Reports 2019;4.

[3] Befus DR, Irby MB, Coeytaux RR, Penzien DB. A Critical Exploration of Migraine as a Health Disparity: the Imperative of an Equity-Oriented, Intersectional Approach. Current Pain and Headache Reports 2018;22.

[4] Belton J, Hoens A, Scott A, Ardern CL. Patients as partners in research: It’s the right thing to do. Journal of Orthopaedic and Sports Physical Therapy 2019;49:623–626.

[5] Bimpong K, Thomson K, Mcnamara CL, Balaj M, Akhter N, Bambra C, Todd A. The Gender Pain Gap: gender inequalities in pain across 19 European countries. Scandinavian Journal of Public Health 2021.

[6] Blyth FM, Schneider CH. Global burden of pain and global pain policy-creating a purposeful body of evidence. Pain 2018;159:S43–S48.

[7] Bond M, Frcs D, Frce F, Kb F. Pain education issues in developing countries and responses to them by the International Association for the Study of Pain PROBLEMS ASSOCIATED WITH THE TREATMENT OF PAIN IN DEVELOPING COUNTRIES. n.d. Available: http://palliumindia.org.

[8] Clark J, Gnanapragasam S, Greenley S, Pearce J, Johnson M. Perceptions and experiences of laws and regulations governing access to opioids in South, Southeast, East and Central Asia: A systematic review, critical interpretative synthesis and development of a conceptual framework. Palliative Medicine 2021;35:59–75.

[9] Devan H, Perry MA, Yaghoubi M, Hale L. “A coalition of the willing”: experiences of co-designing an online pain management programme (iSelf-help) for people with persistent pain. Research Involvement and Engagement 2021;7.

[10] Gilson AM, Maurer MA, LeBaron VT, Ryan KM, Cleary JF. Multivariate analysis of countries’ government and health-care system influences on opioid availability for cancer pain relief and palliative care: More than a function of human development. Palliative Medicine 2013;27:105–114.

[11] Goucke CR, Chaudakshetrin P. Pain: A neglected problem in the low-resource setting. Anesthesia and Analgesia 2018;126:1283–1286.

[12] Harris M, Macinko J, Jimenez G, Mullachery P. Measuring the bias against low-income country research: An Implicit Association Test. Globalization and Health 2017;13.

[13] Hoffman KM, Trawalter S, Axt JR, Oliver MN. Racial bias in pain assessment and treatment recommendations, and false beliefs about biological differences between blacks and whites. Proceedings of the National Academy of Sciences of the United States of America 2016;113:4296–4301.

[14] Jackson T, Thomas S, Stabile V, Shotwell M, Han X, McQueen K. A Systematic Review and Meta-Analysis of the Global Burden of Chronic Pain Without Clear Etiology in Low- and Middle-Income Countries: Trends in Heterogeneous Data and a Proposal for New Assessment Methods. Anesthesia and Analgesia. Lippincott Williams and Wilkins, 2016, Vol. 123. pp. 739–748.

[15] Janevic MR, Mathur VA, Booker SQ, Morais C, Meints SM, Yeager KA, Meghani SH. Making Pain Research More Inclusive: Why and How. Journal of Pain 2021.

[16] Janevic MR, Mathur VA, Booker SQ, Morais C, Meints SM, Yeager KA, Meghani SH. Making Pain Research More Inclusive: Why and How. Journal of Pain 2021.

[17] Kalbarczyk A, Rodriguez DC, Mahendradhata Y, Sarker M, Seme A, Majumdar P, Akinyemi OO, Kayembe P, Alonge OO. Barriers and facilitators to knowledge translation activities within academic institutions in low- And middle-income countries. Health Policy and Planning 2021;36:728–739.

[18] Kawi J, Reyes AT, Arenas RA. Exploring Pain Management Among Asian Immigrants with Chronic Pain: Self-Management and Resilience. Journal of Immigrant and Minority Health 2019;21:1123–1136.

[19] Kintu A, Abdulla S, Lubikire A, Nabukenya MT, Igaga E, Bulamba F, Semakula D, Olufolabi AJ. Postoperative pain after cesarean section: Assessment and management in a tertiary hospital in a low-income country. BMC Health Services Research 2019;19.

[20] Lee P, le Saux M, Siegel R, Goyal M, Chen C, Ma Y, Meltzer AC. Racial and ethnic disparities in the management of acute pain in US emergency departments: Meta-analysis and systematic review. American Journal of Emergency Medicine 2019;37:1770–1777.

[21] Lewis GN, Borotkanics R, Upsdell A. Inequity in outcomes from New Zealand chronic pain services. 2021;134:1533. Available: www.nzma.org.nz/journal.

[22] Lewis GN, Upsdell A. Ethnic disparities in attendance at New Zealand’s chronic pain services. NZMJ 2018;131:1472. Available: www.nzma.org.nz/journal.

[23] Marchetti Calônego MA, Sikandar S, Ferris FD, Moreira de Barros GA. Spread the Word: There Are Two Opioid Crises! Drugs 2020;80:1147–1154.

[24] Mazure CM, Jones DP. Twenty years and still counting: Including women as participants and studying sex and gender in biomedical research. BMC Women’s Health 2015;15.

[25] Meghani SH, Byun E, Gallagher RM. Time to Take Stock: A Meta-Analysis and Systematic Review of Analgesic Treatment Disparities for Pain in the United Statesp me_1310 150..174. n.d. Available: https://academic.oup.com/painmedicine/article/13/2/150/1935962.

[26] Meints SM, Cortes A, Morais CA, Edwards RR. Racial and ethnic differences in the experience and treatment of noncancer pain. Pain management 2019;9:317–334.

[27] Mogil JS. Qualitative sex differences in pain processing: emerging evidence of a biased literature. Nature Reviews Neuroscience 2020;21:353–365.

[28] Mogil JS, Chanda ML. The case for the inclusion of female subjects in basic science studies of pain. Pain 2005;117:1–5.

[29] Morales ME, Yong RJ. Racial and Ethnic Disparities in the Treatment of Chronic Pain. Pain medicine (Malden, Mass) 2021;22:75–90.

[30] Mustafa N, Einstein G, MacNeill M, Watt-Watson J. The lived experiences of chronic pain among immigrant Indian-Canadian women: A phenomenological analysis. Canadian Journal of Pain 2020;4:40–50.

[31] Nguyen M, Ugarte C, Fuller I, Haas G, Portenoy RK. Access to care for chronic pain: Racial and ethnic differences. Journal of Pain 2005;6:301–314.

[32] Quiton RL, Leibel DK, Boyd EL, Waldstein SR, Evans MK, Zonderman AB. Sociodemographic patterns of pain in an urban community sample: an examination of intersectional effects of sex, race, age, and poverty status. Pain 2020;161:1044–1051.

[33] de Ruddere L, Craig KD. Understanding stigma and chronic pain: A-state-of-the-art review. Pain 2016;157:1607–1610.

[34] Sharma S, Jensen MP, Pathak A, Sharma S, Pokharel M, Abbott JH. State of clinical pain research in Nepal: A systematic scoping review. Pain Reports 2019;4.

[35] Thompson KA, Terry EL, Sibille KT, Gossett EW, Ross EN, Bartley EJ, Glover TL, Vaughn IA, Cardoso JS, Sotolongo A, Staud R, Hughes LB, Edberg JC, Redden DT, Bradley LA, Fillingim RB, Goodin BR. At the Intersection of Ethnicity/Race and Poverty: Knee Pain and Physical Function. Journal of Racial and Ethnic Health Disparities 2019;6:1131–1143.

[36] Torres CA, Thorn BE, Kapoor S, DeMonte C. An examination of cultural values and pain management in foreign-born Spanish-speaking Hispanics seeking care at a federally qualified health center. Pain Medicine (United States) 2017;18:2058–2069.

[37] Tuck NL, Khuvtsagaan B, Rashid U, Aamir T, Goucke R, Regjii B, Dorjbal EA, Lundeg G, Bean DJ. The Adaptation of Pain Assessment Tools from High-Income to Low- and Middle-Income Countries: Psychometric Properties of a Set of Chronic Pain Questionnaires in Mongolian and New Zealand Patient Samples. Pain medicine (Malden, Mass) 2021;22:948–960.

AUTHORS

The authors would like to acknowledge the feedback and improvements from reviewers:

Frank Keefe PhD, Duke University Medical School, USA
Ramakrishnan Mani DAc BPhty MPhty PhD, University of Otago, NZ
Guilherme Barros MD PhD, Botucatu Medical School-UNSEP, Brazil