In 1991, the Institute of Medicine published a report "The Computer-Based Patient Record: An Essential Technology for Health Care."

Since then, massive efforts have been focused on building a functional electronic health (or medical) records (EHR or EMR). This was accelerated in 2004 when President Bush announced a comprehensive initiative to digitize the health care system. Today every hospital and/or physician is either in the process of using, installing or actively preparing for an EHR.

At the same time providers are striving to automate their health data, an alternative concept is emerging. The personal health record, or PHR, is a health record being focused on the consumer (rather than the provider) and many argue it represents the best chance to transform the delivery of health care.

PHR's mean different things to different people. Typically, a PHR is some form of electronic repository in which a person can store their health-related information securely and privately and possibly share that information with other providers, individuals or entities at their discretion. The key difference from an EHR is that the individual controls the PHR.

It is estimated there are nearly 200 mature PHR products available in the market today. They vary widely in terms of architecture, format, features, functions and business models. Some are being sold by proprietary vendors, others are offered by insurers, hospitals, employers or advocacy groups.

At the heart of all these products is the premise that the individual will benefit by being able to collect, organize and regularly contribute to a record of their interactions with a fragmented health care system. Many are web-based and offer providers a consistent opportunity to access, and even contribute, data.

PHR's generally fall into one of two categories — tethered and untethered. Tethered products are often affiliated with a provider organization, health plan or employer and are integrated (i.e. tethered) to the information system of the organization. If you have such a PHR from your local hospital, for example, you can often access an abstract of your medical record, see test results, message with physicians and possibly schedule appointments. If tethered to an insurance company, you are likely able to view your claims history and/or pharmacy data. If tethered to your employer, you probably are able to access information from your health risk assessment and view activity in our HSA.

Untethered PHRs are stand-alone records that require the individual to type, scan or download relevant data such as diagnoses, treatments, medications, allergies, and observations regarding health and treatment plans.

It's hard to argue against the value of having a consolidated source for your lifelong health data. Anyone who has been a patient or helped navigate care for a loved one between multiple physicians and hospitals wishes they all had access to the same data. But why haven't PHR's taken off in the market?

With such a wide variety of PHR options available, critics of PHR's note that individual products struggle to capture market share and be sustainable options for a large part of the population. The largest barrier to widespread PHR adoption has been the absence of health information technology standards that allow different information systems to easily integrate data.

Proponents of PHRs are confident that these tools will someday dominate the market. With mega-supporters like Wal-Mart, Microsoft and Google now developing PHR products, I think you'll see PHR's emerge that can seamlessly link to your provider's electronic record while incorporating a host of useful educational, home-monitoring and alert components. Medicare recently announced plans for a PHR pilot program that links seniors to their providers.

I think the key determinant of PHR viability is whether individuals will see them as part of taking accountability for their own health. Who knows, it could be the next trend in blogging.