Early lessons from four 'aligning forces for quality' communities bolster the case for patient-centered care.

The practice of patient-centered care remains in its developmental stages-hampered, in part, by limited evidence of its effectiveness. In this article we first review available evidence on patient-centered care, such as the positive effects of engaging patients in quality improvement activities. We also point out the existence of a research gap that makes it difficult to quantify the effect of "culture change" in health care, and to attribute improvements specifically to patients' involvement.