Trend data play a valuable role in quality improvement. Results of our formative research showed that communities that publicly report trend data are using it as a quality improvement indicator and tool. While its usefulness to consumers is uncertain at best, trend data can help providers (e.g., hospitals, physician offices) monitor their progress, compare their progress with their peers, and share best practices to facilitate improvement.

Physicians—interviewed as part of related research on displaying cost and resource use information—reported that trends in costs, resource use, and quality measures provide valuable information and insights regarding the results of new initiatives, changes, or reforms at the physician, office, and community levels. For example, trend data can show whether current practices or new initiatives are effective at controlling diabetics' HbA1c levels. One physician described how trend data serve as better indicators of provider performance because a single patient can skew results when only a single year of data is available.

Just as providers can use trend data to inform quality improvement efforts, other stakeholders can use the data to guide policy and program-level decisions. Website administrators reported health care purchasers use trend data to inform purchasing decisions, payment negotiations, and pay-for-performance programs. Another website administrator shared anecdotal evidence indicating policy-makers use trend information for resource planning and other types of decisions.

Given the utility of trend data for these professional audiences, it may make sense to display trend data in an area of the website intended for such audiences, rather than with information targeting consumers.