As Barack Obama begins his first term as president, many US minorities will be watching to see what action he takes to improve healthcare.

Although there are persistent racial and ethnic inequalities in services such as education and housing, inequalities in health - described by Martin Luther King as "the worst injustice of all" - are seen as a high priority. In a few decades, the US will be a majority non-white nation. Without reform, millions will continue to experience substandard healthcare services.

Reducing racial "disparities" (as inequalities are called here in the US) in health and healthcare featured in President Obama's election healthcare plan. Of course, extending healthcare coverage is critical: African American and Hispanic people are more likely than white Americans to be uninsured or underinsured. But extending access is unlikely to end disparities on its own and President Obama has promised evidence based interventions, such as health navigators, as well.

Also in the plan is a radical suggestion to enable resources to be targeted more effectively. Hospitals and health plans will be required to "collect, analyse and report quality data about disparity populations" and be held accountable for any differences found. Even though the US has good macro-level data about ethnic groups (for example, death certificates include racial or ethnic group), routine racial and ethnic data about healthcare use and quality is mostly absent at a primary care or hospital level.

Good data is at the heart of effective action to reduce disparities. Much interest has been generated by the example of Chicago's breast cancer
task force, which was set up after research found that a huge disparity had opened up in mortality rates between white and African American patients since the 1980s, when there had been no difference. Amid much media interest, academics, clinicians and city and community representatives volunteered their time to gather local data (including the views of local women) to investigate the disparity.

The root causes, published in 2007, were found to be lack of access to mammography (free in principle but a long bus journey for low income women), poor quality mammographies and poor quality treatment. Some causes were uniquely American - hospitals avoiding treating uninsured women - but others were more universal, such as lack of patient trust, difficulties with access and poor knowledge. The task force plans to collect race and ethnicity data on breast cancer care quality from all Chicago hospitals (public and private) and publish it on the web.

If Barack Obama's presidency can bring about better data collection it will make efforts like Chicago's much easier. While it is easy to dismiss this as a US problem, could any large British city say with any confidence that access to cancer services was equitable? With no routine ethnicity data about mortality, screening, referral rates or waiting times, we had better hope that these sorts of disparities are indeed a uniquely US problem.