Carmen R. Green

Racial and Ethnic Disparities in Pain: Causes and Consequences of Unequal Care

UNLABELLED The purpose of our review is to evaluate critically the recent literature on racial and ethnic disparities in pain and to determine how far we have come toward reducing and eliminating disparities in pain. We examined peer-reviewed research articles published between 1990 and early 2009 that focused on racial and ethnic disparities in pain in the United States. The databases used were PubMed, Medline, Scopus, CINAHL, and PsycInfo. The probable causes of minority group disparities in pain are discussed, along with suggested strategies for eliminating pain-related disparities. This review reveals the persistence of racial and ethnic disparities in acute, chronic, cancer, and palliative pain care across the lifespan and treatment settings, with minorities receiving lesser quality pain care than non-Hispanic whites. Although health and health care disparities attract local, state, and federal attention, disparities in pain care continue to be missing from publicized public health agendas and health care reform plans. Ensuring optimal pain care for all is critically important from a public health and policy perspective. A robust research program on disparities in pain is needed, and the results must be successfully translated into practices and policies specifically designed to reduce and eliminate disparities in care. PERSPECTIVE This review evaluates the recent literature on racial and ethnic disparities in pain and pain treatment. Racial and ethnic disparities in acute pain, chronic cancer pain, and palliative pain care continue to persist. Rigorous research is needed to develop interventions, practices, and policies for eliminating disparities in pain.

Cancer-related chronic pain

Disparities in cancer survival and pain rates negatively impact quality of life (QOL). This study examines cancer‐related chronic pain (CP) and its impact on QOL in diverse cancer survivors.

Race and chronic pain: a comparative study of young black and white Americans presenting for management

Chronic pain is a debilitating problem for many Americans. It affects physical, social, and emotional health. This study addresses the potential differential effects of chronic pain cross-culturally in younger Americans. A retrospective analysis of persons younger than 50 years of age presenting for chronic pain management in a multidisciplinary pain center was done. White and black American adults aged 18 to 50 years (N = 3669) were compared to determine whether there were differences in (1) psychologic functioning, (2) pain characteristics, (3) pain disability, and (4) comorbidities. Our results suggest that black Americans had more depressive symptoms and symptoms consistent with post-traumatic stress disorder when compared to white Americans. These results showed that on initial assessment, black Americans with chronic pain report significantly more pain and sleep disturbance as well as more symptoms consistent with post-traumatic stress disorder and depression than white Americans. They also experience a higher prevalence of self-identified comorbidities, including dizziness, chest pain, and high blood pressure. In conclusion, considerable diminution in the overall physical and emotional health of black Americans 18 to 50 years of age with chronic pain was noted. These data support the need for further study of the chronic pain experiences of racial and ethnicity minority persons.

Socioeconomic disadvantage and pain

Socioeconomic disadvantage (SED) and its contribution to the pain experience is of growing interest and relevance. This review will provide a brief overview of definitional and measurement issues related to SED. Selected literature considering the relationships between SED and pain will then be summarized, and several possible mechanisms to explain the relationships will be considered. Last, future directions for research and practice will be discussed.

Do Physical And Sexual Abuse Differentially Affect Chronic Pain States in Women

To evaluate the role of physical and/or sexual abuse on chronic pain symptoms and health care utilization in women, 104 consecutive female patients presenting to a multidisciplinary pain center for management of chronic pain were surveyed. Outcomes included a measure of sexual or physical abuse history (Drossman Sexual-Physical Abuse Survey), and measures of anxiety, health care utilization, substance abuse, and somatic symptoms. Forty-eight percent of the sample reported a history of physical abuse (PA) or sexual abuse (SA). Forty percent of the abused patients reported both PA and SA and the remainder reported SA (37%) or PA (23%) alone. The women who reported abuse had increased pain, physical symptoms, anxiety symptoms, and mental health care utilization compared to nonabused women. The women who reported abuse were also more likely to smoke and abuse street drugs. Women who reported both PA and SA were more likely to report head pain when compared to those who reported only PA or SA. Given the impact of abuse, particularly SA, on the presentation of chronic pain, queries regarding abuse should become a routine component of the patient interview. Abused patients should be referred to mental health care practitioners as a component of successful pain management if unresolved issues persist.

Predictors of Complementary and Alternative Medicine Use in Chronic Pain Patients

OBJECTIVE We used Andersens behavioral model of healthcare utilization to assess the relationship between sociodemographic, physical and psychosocial factors, and Complementary and Alternative Medicine (CAM) use among chronic pain patients. Three practitioner-based alternative therapies were considered: acupuncture, biofeedback/relaxation training, and manipulation services. DESIGN A retrospective analysis of self-reported clinical data with 5,750 black and white adults presenting for initial assessment between 1994 and 2000 at the University of Michigan Multidisciplinary Pain Center was performed. RESULTS CAM therapies were used in high frequencies, with 34.7% users. Specifically 8.3% used acupuncture, 13.0% used biofeedback/relaxation, and 24.9% used manipulation techniques. Race and age were predisposing factors associated with CAM use. Blacks used less biofeedback/relaxation and manipulation services than whites. Aging was related to more acupuncture, but less biofeedback/relaxation use. Women marginally used more biofeedback/relaxation services than men, and education was positively associated with all three CAM use. Perceived pain control was a consistent enabling factor positively correlated with the use of all three CAM services. Among need factors, pain characteristics and physical health were positively associated with at least one of the modalities. Depressive symptoms were not related to CAM services use. CONCLUSION This study identifies variable patterns of CAM usage based on sociodemographic and health factors in chronic pain patients. Overall, who uses CAM depends on the modality; however, education, pain severity, and pain duration are persistent correlates of CAM usage regardless of the therapy considered. We found that mental health, as measured by depressive symptoms, had no noticeable impact on CAM usage among chronic pain patients. The clinical, policy, and research implications of CAM use are discussed.

The role of childhood and adulthood abuse among women presenting for chronic pain management

ObjectiveThis study investigated the association between repeated childhood and adulthood abuse and somatic symptom reporting, mental health care use, and substance use among women with chronic pain. DesignA survey of a consecutive sample. PatientsNinety consecutive women patients presenting for chronic pain management at a multidisciplinary pain management center. Outcome MeasuresThe authors assessed the presence or absence of physical or sexual abuse (using the Drossman Physical-Sexual Abuse Survey), period of abuse, demographics, mental health care use, drug or alcohol use and substance abuse, and the presence or absence of physical, pain, and anxiety (somatic) symptoms. ResultsThe response rate among patients surveyed was 64%. Of the 43 respondents (48%) who reported abuse, 17 (40%) cited childhood abuse, 12 (28%) cited adulthood abuse, and 14 (33%) cited repeated abuse. Women describing long-term abuse reported a significantly greater number of physical, pain, and anxiety symptoms and were more likely to report a history of substance abuse than women reporting abuse during childhood or adulthood alone. ConclusionsThese data indicate a significant association between health status and reported abuse among women presenting to a multidisciplinary pain center for pain management. This finding is consistent with those of previous investigators, and emphasizes the importance of routine evaluation of the presence of long-term abuse as a possible predictor of the onset of chronic pain states.

Consistent and breakthrough pain in diverse advanced cancer patients: a longitudinal examination.

Although cancer pain, both consistent and breakthrough pain ([BTP]; pain flares interrupting well-controlled baseline pain), is common among cancer patients, its prevalence, characteristics, etiology, and impact on health-related quality of life (HRQOL) are poorly understood. This longitudinal study examined the experience and treatment of cancer-related pain over six months, including an evaluation of ethnic differences. Patients with Stage III or IV breast, prostate, colorectal, or lung cancer, or Stage II-IV multiple myeloma with BTP completed surveys on initial assessment and at three and six months. Each survey assessed consistent pain, BTP, depressed affect, active coping ability, and HRQOL. Among the respondents (n=96), 70% were white, 66% were female, and had a mean age of 56+/-10 years. Nonwhites reported significantly greater severity for consistent pain at its worst (P = 0.009), least (P < or = 0.001), on average (P = 0.004), and upon initial assessment (P = 0.04), and greater severity for BTP at its worst (P = 0.03), least (P = 0.02), and at initial assessment (P = 0.008). Women also had higher levels of some BTP measures. Ethnic disparities persisted when data estimation techniques were used. Examined longitudinally, consistent pain on average and several BTP measures reduced over time, although not greatly, indicating the persistence of pain in the cancer experience. These data provide evidence for the significant toll of cancer pain, while demonstrating further health care disparities in the cancer pain experience.

The role of irrigation in the development of hypothermia during laparoscopic surgery

OBJECTIVES Our purpose was to determine the incidence and etiology of hypothermia during laparoscopic surgery and to evaluate the role of irrigation fluid temperature. STUDY DESIGN A prospective randomized study was performed of 35 women undergoing operative laparoscopy under general anesthesia who received surgical irrigation fluid either at ambient temperature or warmed to 39 degrees C. The core body temperature was determined with use of both an esophageal sensor and a tympanic membrane sensor and was expressed as the change from baseline. Additional data collected included age, height, weight, amount of irrigation fluid and intravenous fluid used, room temperature, length of anesthesia, and amount of carbon dioxide used for pneumoperitoneum. RESULTS Hypothermia occurred in 94% of all patients, with no difference in incidence between the groups. The minimal core temperature was lower in the ambient temperature group (-1.7 degrees +/- 0.2 degrees C) than in the warmed fluid group (-1.0 degrees +/- 0.2 degrees C). Of the variables measured, length of anesthesia and the amount of ambient temperature fluid alone explained the drop in core temperature. CONCLUSION Hypothermia is extremely common in laparoscopic surgery and is related to the length of anesthesia and the use of ambient temperature irrigation fluid. The use of warmed irrigation fluid can decrease, but not eliminate, this drop in core temperature.

Chronic Back Pain Is Associated with Alterations in Dopamine Neurotransmission in the Ventral Striatum.

Back pain is common in the general population, but only a subgroup of back pain patients develops a disabling chronic pain state. The reasons for this are incompletely understood, but recent evidence implies that both preexisting and pain-related variations in the structure and function of the nervous system may contribute significantly to the development of chronic pain. Here, we addressed the role of striatal dopamine (DA) D2/D3 receptor (D2/D3R) function in chronic non-neuropathic back pain (CNBP) by comparing CNBP patients and healthy controls using PET and the D2/D3R-selective radioligand [11C]raclopride. D2/D3R availability was measured at baseline and during a pain challenge, yielding in vivo measures of receptor availability (binding potential, BPND) and DA release (change in BPND from baseline to activated state). At baseline, CNBP patients demonstrated reductions in D2/D3R BPND in the ventral striatum compared with controls. These reductions were associated with greater positive affect scores and pain tolerance measures. The reductions in D2/D3R BPND were also correlated with μ-opioid receptor BPND and pain-induced endogenous opioid system activation in the amygdala, further associated with measures of positive affect, the affective component of back pain and pain tolerance. During the pain challenge, lower magnitudes of DA release, and therefore D2/D3R activation, were also found in the ventral striatum in the CNBP sample compared with controls. Our results show that CNBP is associated with adaptations in ventral striatal D2/D3R function, which, together with endogenous opioid system function, contribute to the sensory and affective-motivational features of CNBP. SIGNIFICANCE STATEMENT The neural systems that underlie chronic pain remain poorly understood. Here, using PET, we provide insight into the molecular mechanisms that regulate sensory and affective dimensions of pain in chronic back pain patients. We found that patients with back pain have alterations in brain dopamine function that are associated with measures of pain sensitivity and affective state, but also with brain endogenous opioid system functional measures. These findings suggest that brain dopamine–opioid interactions are involved in the pathophysiology of chronic pain, which has potential therapeutic implications. Our results may also help to explain individual variation in susceptibility to opioid medication misuse and eventual addiction in the context of chronic pain.