services) and survival among members of the same managed care plan (Yood, Johnson, and Blount, 1999).

When individuals who live in the same general area and share many socioeconomic characteristics other than race or ethnicity receive different patterns of care, explanations for these differences are likely to be found in the dynamics of physician decision making, doctor-patient interaction, individual attitudes and beliefs about illness and treatment, or organizational characteristics of health care systems (Grantmakers in Health, 2000).

There have been some studies documenting differences in physician recommendations or referral patterns for cardiac surgery as a function of patient race or gender, even when other characteristics were controlled (Grantmakers in Health, 2002). Studies of disparities in dose of adjuvant chemotherapy for women with breast cancer have also identified individual physician decision making as a key factor (LaVeist, Morgan, and Arthur, 2002). When the causal factors related to disparities cannot be identified so closely with specific individuals, though, there are a number of characteristics of organizations or health care systems that have been linked to either the current existence of disparities or their potential reduction or elimination. These factors include institutional racism (Williams and Rucker, 2000) cultural competence (Cohen and Goode, 1999), or “patient-centeredness (Picker Institute).”

As research and health policy attention shifts from the documentation of disparities to the testing of initiatives to reduce disparities, the role of organizations such as hospitals, health plans, and medical groups will be crucial. Each currently plays an important role in quality measurement, quality improvement, and establishing the norms, values, and systems for accountability of medical care. If we follow the recommendation of a recent IOM panel and view disparities as an important quality of care problem (IOM, 2003), then it is important to understand how hospitals, health plans, and medical groups can play a role in reducing disparities.

In the domains of quality measurement and quality improvement, these organizations already play important roles, as indicated below.

Hospitals:

• Responsible for assessing and ensuring quality for inpatient care

• Able to establish and enforce clinical policies and guidelines

• Able to produce clinician profiles for quality and cost of care

• Able to grant or rescind privileges

• Subject to external review for both accreditation and licensing purposes

Health plans:

• Accountable to public and private purchasers for achieving stan-