To provide good care for people with chronic illness, clinicians need access to timely, clinically relevant information about each patient in the practice, as well as the population of patients as a whole. Useful information includes recommended services (e.g., an Asthma Action Plan), key outcome measures (e.g., symptom-free days, ER visits), patient contact information, and patient encounter history (e.g., how often patient accesses care; last time seen).

A system that records all relevant patient care information is often referred to as a "registry." Providers can use the registry to record critical elements of the care plan, produce quick care summaries at the time of a visit, and enter data to alter the care plan as needed. A patient registry is most useful when patient data is available to the provider at the point of the patient visit when decision support is most needed.

The registry can remind providers of needed services, represent feedback on performance of both the clinic and the provider, and serve as a source of up-to-date information for encounters. Health care teams can also use the registry to contact groups of patients with similar care needs and deliver planned care and educational sessions.