Results

Our initial search produced 586 titles and abstracts, of which 66 appeared potentially relevant. Of these, 35 met our inclusion criteria. Our supplemental search strategies added 20 studies meeting our inclusion criteria, resulting in a total of 55 included studies: 17 for service patterns, 36 for concordance, and two for trust in health care. We were not able to identify any empirical studies addressing the hypothesis that greater health professions diversity results in greater advocacy or implementation of programs and policies targeting health care for minority or other disadvantaged populations.

Service Patterns

Racial and Ethnic Minority Health Professionals. We identified 17 studies addressing the service patterns of racial and ethnic minority health professionals. Of these, 16 examined physicians’ and one reported dentists’ service patterns. These studies were overwhelmingly consistent in supporting the hypotheses that minority health professionals are more likely than non-minorities to serve both minority and other underserved populations, including the poor and uninsured (Table 2, Appendix A).

Thirteen separate studies have documented that minority physicians tend to provide a disproportionately large share of health care for patients from their own racial and ethnic backgrounds.(18-30) In one recent study, Bach and colleagues found that in a national sample of Medicare beneficiaries, 22 percent of African-American patients’ visits in 2001 were to African- American physicians, who make up roughly 4.5 percent of the Nation’s physicians.(18) Notably, this disproportionate pairing appears to be a result of both African-American physicians locating their practices in African-American communities, and of African-American patients’ preferentially seeking out African-American physicians. Bach at al. found that African-Americans physicians comprised 12.5 percent of physicians in the service areas where African-American patients sought care, well above the representation of African-Americans in the physician workforce, but well below the proportion of race concordant visits between African-American patients and physicians.(18) In another study, Saha and colleagues found that African-American patients tended to choose African-American physicians, independent of the convenience of the physicians’ office location.(29) This disproportionate pairing of patients and physicians of the same race is true not only for African-Americans but also for other racial and ethnic minorities. In a national survey from 2001, 24.5 percent of African-Americans, 27.6 percent of Latinos, and 45.3 percent of Asians reported having a regular physician from their own racial group, figures that are all well above the proportion of each of these racial groups in the U.S. physician workforce.(28) Finally, it should be noted that minority physicians not only disproportionately serve patients from their own racial and ethnic groups, but they also disproportionately serve other minority patients as well.(20, 24, 31)

In addition to serving minority populations, minority health professionals tend to serve other disadvantaged populations to a greater extent than non-minority professionals do.(19, 21-24, 26, 27, 30-34) Studies have provided compelling evidence that minority physicians are more likely than non-minority physicians to care for poor patients,(19, 21, 23, 24, 30, 33) those insured by
Medicaid (19, 22-24, 30-33), those without health insurance,(19, 23, 24, 31, 33) and those living in areas with health professional shortages.(22, 23, 33) In the one study we identified that examined service patterns for minority health professionals other than physicians, Mofidi et al. found that among dentists who had served in the National Health Service Corps (NHSC)—a program providing loan repayment to health professionals in exchange for a period of service in an underserved community—African-American race was the strongest predictor of continuing to work in the underserved community beyond the NHSC obligation period.(34)

Some of the studies cited above have addressed key issues relevant to minority providers’ service of the underserved. First, some may argue that minority professionals serve in minority and underserved communities not by choice but because they are less able, possibly due to lower academic performance, to compete for positions in more affluent communities. Two studies, however, examined service patterns at the University of California, San Francisco, and the University of California, San Diego, both ranked among the most prestigious medical schools in the Nation.(35) These studies revealed that even among students from these elite institutions, whose graduates likely have substantial choice regarding practice type and location, minority physicians were substantially more likely than their non-minority classmates to serve minority and underserved communities.(23, 27)

Second, several studies have demonstrated that race is a stronger predictor than socioeconomic background of serving the underserved.(19, 31, 33) For instance, Brotherton et al. demonstrated in a national sample of pediatricians that URM physicians cared for more Medicaid and uninsured patients than non-URM physicians, regardless of socioeconomic background. In fact, URM pediatricians from relatively privileged backgrounds, as measured by having parents who were professionals or had at least a college degree, cared for more uninsured and Medicaid patients than non-URM physicians from underprivileged backgrounds.(31) Findings such as this indicate that, with regard to increasing the number of health professionals caring for underserved populations, diversity programs targeting only individuals from socioeconomically disadvantaged backgrounds will likely be less effective than programs that explicitly consider race and ethnicity.

Finally, findings from several studies have countered the notion that providing health professionals with financial incentives to serve underserved populations may substitute for diversity programs as a way to ensure adequate access to care for the underserved.(30, 31, 33) These studies have examined the primary financial incentive program used for this purpose, the National Health Service Corps (NHSC). In each of these studies, while NHSC participation was associated with a higher likelihood of going on to care for underserved populations, URM race was always a stronger predictor than NHSC participation.(30, 31, 33) In fact, URM physicians without NHSC obligations were more likely to serve the underserved than non-URM physician with NHSC obligations.(30, 31) This suggests that diversity programs might be a more effective long-term investment than the NHSC, in terms of providing access to health professionals for the medically underserved.

Health Professionals from Socioeconomically Disadvantaged Backgrounds. As noted above, several studies have examined physician service patterns as a function of socioeconomic background.(19, 31, 33) Rabinowitz et al. surveyed a national sample of physicians and asked about their family income during childhood. The authors found that this measure of socioeconomic background, stratified into quintiles, was not associated with care for underserved populations, designated as: working in a federally designated Health Professional Shortage Area or Medically Underserved Area; or having a practice in which over 40 percent of patients were either uninsured, or on Medicaid or poor.(33) Similarly, Brotherton et al. did not find an association between socioeconomic background, as measured by parental education and occupation, and the proportion of pediatricians’ patients who were from racial or ethnic minorities or were uninsured or on Medicaid.(31) Cantor et al. did find an association between disadvantaged socioeconomic background and care of underserved groups, though the association was relatively weak, and as noted above, was small in comparison to the effect of URM race.(19)

Concordance

We identified 36 studies addressing the effects of patient-practitioner racial, ethnic, and/or language concordance on health care access/utilization, quality, and outcomes. We defined a study as addressing race concordance when individuals were categorized according to the major racial/ethnic categories used by the U.S. Census Bureau: White/Caucasian, Black/African-American, Hispanic/Latino, Asian, Pacific Islander, and American Indian/Alaska Native. We labeled studies as addressing ethnic concordance if they considered concordance as being present between people who were from more specific subgroups, based on nationality or other affiliations. For instance, if a patient and practitioner who were both Latino were categorized as concordant, we considered this to represent race concordance. If concordance was considered present when patient and practitioner were both of Mexican origin, we considered this to represent ethnic concordance.

Most of the studies we identified examined concordance between patients and physicians, or between mental health clients and their therapists (Table 3). These studies addressed three different categories of outcome measures: access to care or utilization of health services, quality of care, and health care outcomes.

Racial/Ethnic Concordance

Studies addressing the effects of patient-practitioner racial or ethnic concordance on access to care and use of health services, quality of care, and health outcomes provided mixed results (Table 4, Appendix B).

Access/Utilization. Four studies assessed the effect of patient-physician race concordance on access to care and use of health services.(28, 36-38) In a national survey conducted in 1994, Saha and colleagues found that race concordance was associated with a lower likelihood of having unmet health needs and a greater likelihood of self-reported receipt of preventive care for African-Americans, but not for Latinos.(36) In two other studies, race concordance was not associated with receipt of appropriate preventive care or disease management services among African-Americans, Latinos, or Asians,(28) or with care seeking delays, emergency department use, or medication adherence among African-Americans with hypertension.(37) In the fourth study, Chen et al. tested the association between race concordance and use of coronary angiography among Medicare beneficiaries hospitalized for acute myocardial infarction (AMI).(38) This was an important study, in that it examined the role of patient-physician race discordance in explaining one of the most well-documented racial disparities in health care (i.e., disparities in the use of coronary angiography).(39) The authors found that race concordance was not associated with use of coronary angiography, in both unadjusted analyses and analyses accounting for patient, physician, and hospital characteristics. It should be noted, however, that the physician whose race was determined to be concordant or discordant with the patient’s in this study was the attending physician for the hospital stay. This may or may not have been a physician with whom the patient had a relationship pre-dating the hospitalization or the physician who served as the patient’s principal agent in guiding decision making.

Eleven studies examined the effect of client-therapist racial or ethnic matching on utilization of mental health services.(40-50) All but one of the studies were conducted in the context of county mental health agencies in California, many of them taking advantage of administrative databases maintained by those counties.(40-49) Therapists included a broad array of health professionals, including social workers, psychiatrists, psychologists, clinical nurse specialists, and unlicensed mental health workers. The studies examined the effect of client-therapist racial or ethnic concordance on measures intended to capture adherence to outpatient mental health therapy, including the total number of visits attended and dropout from therapy. In general, the studies demonstrated that racial and ethnic concordance was associated with greater use of mental health services and lower dropout rates,(40, 42, 43, 45-50) as well as lower use of emergency services. (47) Two studies found mixed or null results.(41, 44)

Four studies assessed whether race concordance between substance abuse clients and counselors was associated with greater attendance or participation in therapy.(51-54) With the exception of one isolated finding from two separate studies by the same authors, these studies found no effect of concordance on utilization patterns among substance abuse clients. In the two studies with significant findings, African-American clients with African-American counselors were less likely to use substance abuse treatment after therapy ended.(53, 54)

Quality. Thirteen studies evaluated the association between patient-physician race concordance and quality of care.(28, 36, 37, 55-63) Most of the studies used patients’ ratings of interpersonal care (e.g., patient satisfaction) as the principal measure of quality. The majority of these studies found that race concordance was associated with better interpersonal care.(36, 55-58, 60, 61, 63) Another study found a similar association between patient-counselor race concordance and empathy for substance abuse clients.(51)

Three of the studies went beyond interpersonal care to evaluate the impact of concordance on other measures of quality.(28, 59, 62) One study found no association between patient-physician race concordance and parents’ evaluations of both interpersonal and technical aspects of their children’s primary care.(62) In another study, race concordance was not associated with patients’ self-reported receipt of appropriate primary care services, such as cholesterol screening or diabetes management for eligible patients.(28) In the third study, King and colleagues examined the quality of care for patients with human immunodeficiency virus (HIV) infection in a large national cohort. They found that patient-provider race concordance among African-Americans was associated with shorter time to receipt of protease inhibitors—medications known to reduce progression to the acquired immunodeficiency syndrome (AIDS) and to prolong life (64, 65) —even after accounting for other patient and provider characteristics.(59) Moreover, the authors found that in the cohort overall, White patients received protease inhibitors earlier than African-Americans, but that among patients with race concordant providers, this disparity was eliminated.

This study is important for two reasons. First, it is one of only two studies that examined the effects of race concordance on the use of health care services proven to reduce morbidity and mortality.(28, 59) Second, the study demonstrated that race concordance was associated with elimination of disparities in an important aspect of treating HIV/AIDS, a disease known to disproportionately affect African-Americans. These two facets of the study suggest that patient-physician race concordance has the capacity to reduce racial disparities not only in health care, but in health and mortality.

Another noteworthy study examined the impact of race concordance on the quality of patients’ communication with their primary care providers.(56) In this study, Cooper and colleagues audiotaped doctor-patient encounters and analyzed the content of the encounters. They found that doctor-patient race concordance was associated with longer visits and measurably better communication.(56) They also found that patients were more satisfied with the visit and rated the doctor as fostering more doctor-patient partnership in race concordant encounters. Notably, however, the authors found that the differences in communication and the differences in patients’ ratings of the visit were independent of each other; i.e., accounting for the differences in communication did not explain any of the differences in patients’ ratings of their doctors. This finding is important in that it illustrates that race concordance is associated not only with better communication but also with other unmeasured aspects of the doctor-patient encounter that give rise to higher patient ratings of health care quality. This suggests that while communication training for health professionals may improve the quality of care for minority patients, it is unlikely to serve as a substitute for increasing the number of minority health professionals, which would increase minority patients’ ability to see race concordant providers if they choose to.

Outcomes. Twelve studies tested for associations between patient-practitioner racial or ethnic concordance and health outcomes.(38, 41-44, 48-51, 53, 54, 63) In most of these studies, the outcome of interest was improvement in global mental health status after a course of mental health counseling or therapy.(41-44, 48-50) These studies produced mixed results, with no clear pattern for patients from any specific racial or ethnic group or with any specific mental health condition. Four of the seven studies did find some evidence of a positive effect of racial or ethnic concordance on mental health outcomes.(43, 44, 48, 50)

In a study comparing adjustment to disability among African-American patients with vitiligo, a disfiguring skin condition, Porter and Beuf found that patients treated at a clinic with predominantly African-American physicians and staff expressed better adjustment than those treated at a clinic with predominantly White physicians and staff.(63) This study was unique in examining race concordance with not only a single health care provider but with the majority of the clinic staff. The study was limited, however, in that it only examined two different health care settings.

Three studies examined the association between patient-counselor race concordance and substance abuse treatment outcomes.(51, 53, 54) One study assessed abstinence from substance use and found that race concordance was not associated with abstinence for any individual racial group, but that women with race concordant counselors were more likely to remain abstinent.(51) In the other two studies, which were conducted by the same group of authors, results were conflicting.(53, 54) Both studies examined cohorts of African-American patients in cocaine treatment programs. In one study, patient-counselor race concordance was associated with more medical and legal problems nine months after treatment.(53) In the other study, race concordance was associated with a lower likelihood of having been jailed within nine months of treatment.(54) Notably, in both studies, the authors tested for multiple treatment outcomes, such that the statistically significant findings mentioned above may have occurred by chance.

Language Concordance

Studies of patient-practitioner language concordance were generally more consistent than those of racial/ethnic concordance in demonstrating a positive effect of concordance on access, utilization, and quality of care (Table 5, Appendix C). Findings of these studies did not reveal a consistent effect of language concordance on health outcomes.

Access/Utilization. Seven studies assessed the impact of patient-practitioner language concordance on access to care and use of health services.(40-42, 47-49, 66) Most of these studies sought to determine whether client-therapist language concordance was associated with measures intended to capture adherence to outpatient mental health therapy, including the total number of visits attended and dropout from therapy.(40-42, 48, 49) The studies generally found beneficial effects for language concordance on these outcomes among both Latino and Asian mental health clients, though the findings were more consistent for Latinos. Another study found that client-therapist language concordance was associated with less use of emergency services for both Latinos and Asians.(47) Finally, in a study of Spanish-speaking patients with asthma, Manson found that patients in continuous relationships with language concordant primary care physicians were less likely than those in language discordant relationships to miss appointments.(66) He also found non-significant trends suggesting that language concordance was associated with greater medication adherence and fewer emergency department visits.(66)

Quality. Four studies of Latino populations tested the association between patient-physician language concordance and the quality of interpersonal care, particularly communication.(67-70) In three of the studies, language concordance was positively associated with interpersonal quality of care.(67, 68, 70) A fifth study examined the influence of patient-physician language concordance on patients’ comprehension of medical information.(71) In this survey of Californians speaking one of eleven different non-English primary languages, respondents with limited English proficiency were more likely than English-proficient respondents to have problems understanding a medical situation and understanding medication labels.

When limited English-proficient patients with language discordant vs. concordant physicians were examined separately, the former group was much more likely to have problems in both of these areas. The latter group was only modestly more likely than English-proficient patients to have difficulty understanding a medical situation and were no more likely to have difficulty with medication labels. These findings, which took into account differences in demographic factors and access to care, indicate that language concordance was associated with significantly greater medical comprehension among individuals with limited English proficiency.(71)

Outcomes. Seven studies assessed the association between language concordance and health outcomes.(41, 42, 48, 49, 69, 71, 72) Four of the studies examined improvements in global mental health status after a course of mental health counseling or therapy.(41, 42, 48, 49) One study found a positive association between language concordance and improved mental health for Latinos but not for Asians;(48) the other studies found no significant associations. Another study examined a group of Latino patients with diabetes and found a non-significant trend suggesting better glycemic control among those with a language concordant primary care physician, though fewer than half of the language concordant providers were themselves Latino.(72)

Perez-Stable and colleagues found an association between patient-physician language concordance and several dimensions of patients’ self-reported health status, though this was a cross-sectional study; the authors were therefore unable to determine whether language concordance was associated with improvements in health status.(69) Finally, in the study of Californians speaking non-English languages discussed in the previous section, limited English-proficient patients with a language discordant physician were significantly more likely than English-proficient patients to report having had a bad reaction due to problems understanding medication instruction. Limited English-proficient patients with a language concordant physician were no more likely than their English-proficient counterparts to have experienced a bad medication reaction.(71)

Trust in Health Care

We found limited evidence addressing the hypothesis that institutional diversity enhances trust among minority or socioeconomically disadvantaged patient populations. Our search generated only two studies that indirectly addressed this hypothesis.(73, 74) In the first, Mouton and colleagues surveyed women who did not respond to an invitation to participate in a large clinical trial.(73) The authors found that 37 percent of the African-American women in the sample expressed a preference to be treated by an African-American scientist. This finding suggests that increasing the number of minority health scientists might enhance minority participation in clinical trials, which might reduce racial disparities in the benefits of medical research. This study, however, was limited in that only 29 African-American women were surveyed, and it was not clear that lack of diversity among researchers was a principal reason for lack of participation among the women who reported a preference.

In the second study, Reese et al. interviewed African-American pastors to elucidate barriers to hospice participation among terminally ill African-American patients.(74) Pastors identified lack of diversity among health professionals as a significant barrier to hospice enrollment. The authors developed and administered a survey of barriers to hospice participation that incorporated lack of diversity among health professionals as a potential barrier. While the authors found that African-Americans were more likely to endorse barriers to participation, they did not report findings for each specific barrier. It was thus not possible to determine whether lack of diversity among health care workers represented a significant barrier in their quantitative analysis.

Professional Advocacy

Insufficient evidence exists as to whether greater health professions diversity leads to greater advocacy for disadvantaged populations. While health professionals from racial and ethnic minority and socioeconomically disadvantaged backgrounds would seem more likely than others to advocate for and implement policies and programs to improve health care for disadvantaged populations, we could find no studies testing this hypothesis.