We rigorously evaluated strategies to improve the quality of care for racial/ethnic minority patients in a select group of studies. Almost all the interventions occurred in the primary care setting, and most focused on the provision of preventive services. Only two of the studies were specifically targeted at the needs of racial/ethnic minority patients [18, 34]; the remaining studies were generic quality improvement strategies. Despite this, there is excellent evidence that provider tracking/reminder systems are effective in improving quality of care for racial/ethnic minority patients (Evidence Grade A), fair evidence that multifaceted interventions, provider education interventions, and interventions that bypass the physician to offer screening services to racial/ethnic minority patients can improve quality of care (Evidence Grade C), and poor evidence for the use of any other of the studied intervention strategies (Evidence Grade D).
Tracking and reminder systems were effective in improving rates of standardized services such as cancer screening [10, 15, 19, 21, 25, 35] and advance directive completion . Although these do not represent all clinical areas for which disparities in care have been documented and thus may hold little potential for addressing overall disparities, the strategy appears effective in improving the process of care for racial/ethnic minorities. In some studies, though, some of the processes of care targeted by tracking and reminder systems were not evidence-based practices for any patient population (for example, oral cavity exams or breast self-examinations for cancer screening) and would therefore be unlikely to improve the quality of care or reduce disparities for racial/ethnic minority patients.
Our review identifies important gaps in knowledge that provide a focus for future research. Regarding strategies worthy of further study, there were several types of interventions with favorable results, but employed in only one or two studies each, thus receiving a grade of either D or C. These are: (1) bypassing the physician to offer standardized services directly to patients [12, 23], (2) use of remote simultaneous translation for patients with limited English proficiency  and (3) the use of a structured questionnaire (Safe Times Questionnaire) for health behaviors risk assessment in adolescents . Of these, the study that evaluated remote simultaneous translation is particularly germane to the needs of some racial/ethnic minorities, and could have widespread impact if the results are replicated in other studies. Also, both of the studies evaluating provider education yielded favorable results [17, 32]; however, other studies have suggested that passive educational interventions are not optimal .
We found poor evidence to determine which strategies are most effective in reducing disparities between minority and white populations (Evidence Grade D). The only study that was specifically designed to do this had mixed results; with improvements in only one of the two outcomes assessed . This represents a critical gap in the literature. More research is needed that is designed specifically to reduce disparities in healthcare quality, for example, research that targets specific diseases (e.g. cardiovascular disease, diabetes, HIV) and healthcare processes known to be a source of racial/ethnic disparities. It may be necessary to distinguish between interventions aimed at improving the quality of care for all persons and those aimed at improving quality of care for racial/ethnic minority populations specifically (such as reducing provider bias or improving intercultural communication skills). When generic quality improvement interventions are done in diverse populations, subgroup analyses that evaluate the effect of the interventions in racial/ethnic minority patients would increase our understanding the effect on equity of treatment.
Many organizations have limited resources to accomplish the goal of improving minority health care quality. Our review found poor evidence to determine the costs of strategies to improve care and reduce disparities for minority populations (Evidence Grade D). Only one study included an estimate of cost. In order to make resource allocation decisions for ethnic minority patient populations in the future, data on the costs of these interventions will be critical.
Additional knowledge gaps to be filled by future research were related to targeted groups, settings, and health outcome assessments. First, there are very few quality improvement interventions that were completed in Hispanic populations and none in American Indians/Alaska Natives or in Asians/Pacific Islanders. Second, almost all studies were done in the primary care setting. Insofar as disparities have been documented in other settings, more studies may be needed in acute care and specialty settings. Finally, few studies measured patient outcomes; most measured healthcare process. This limitation would not be as important if all studies had targeted processes of care that were evidence-based and more closely linked to patient outcomes. Studies need to include patient outcomes, have longer follow-up to determine the sustainability of intervention effects, and link process of care to health outcomes.
There were some challenges in synthesizing this body of literature. First, studies that used multifaceted interventions and did not examine separate components, making it difficult to know exactly what resulted in the beneficial effect observed. Second, each study used slightly different intervention methods, making generalizations across studies difficult. Because no two studies used exactly the same intervention and evaluation strategy, there is a need to replicate and evaluate promising intervention strategies in different healthcare settings and organizations. In addition, multifaceted interventions should be evaluated in such a way so as to distinguish which specific piece of the intervention was most effective.
This review has several limitations. First, eligibility was limited to English language and to published reports of studies. Although our resources did not permit extensive searching of the non-English language and unpublished literature, recent work has suggested that results of reviews with these limits do not differ substantially from reviews with no such limits . There is, however, a possibility of publication bias, in that studies with demonstrated benefit are more likely to be published than those with no benefit. This is a limitation of any systematic review.
Eligibility was also limited to articles published after 1980, and to studies conducted in the United States. There may have been other promising interventions conducted in other countries that are not reflected in this report. Only randomized controlled trials and concurrent controlled trials were included. Although researchers have recommended the use of experimental designs with control groups to evaluate interventions to reduce disparities whenever possible , there have been other worthwhile interventions that have been evaluated with other study designs . Our review, which found a paucity of rigorous clinical trials, suggests that other types of studies should be considered by those interested in designing interventions to reduce disparities. To the extent that other QI strategies are used without a sound evidence base, it may be unfair to hold interventions designed to reduce disparities to a different standard. On the other hand, it is a worthwhile goal that all QI interventions have demonstrated effectiveness. Our review only included interventions targeting providers; interventions directly targeting patients may also be promising strategies to improve the quality of care and reduce racial/ethnic disparities, but they are not reflected in this report.