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One of the first considerations is the storage location. Often an administrator’s first instinct is to store the archives on a storage area network (SAN). However, this is not always the best idea.
Technically, there is nothing wrong with storing archives on a SAN, but doing so is not usually going to be the most cost-effective solution. SANs are almost always designed for high performance and also provide a high degree of redundancy. As such, the cost per gigabit tends to be much higher than that of other types of storage.
The other thing to remember is that, when data is moved to a medical image archive, that data is typically old and is accessed very infrequently. As such, it does not usually make sense to use high-cost, high-performance storage for archived data. It is often better to store archive data on a high capacity storage device made of commodity hardware.
Another big part of designing an archiving system is capacity planning. It isn’t enough to simply estimate the amount of data that currently needs to be archived. Capacity planning involves examining the entire data lifecycle. Administrators must consider the rate at which data is expected to accumulate each year, as well as the length of time for which data will be retained in the archives.
Retention requirements are perhaps the biggest thing a health care organization should take into account when planning for archiving data. The IT department will have to consider both the organization’s own retention requirements, as well as those mandated by HIPAA as well as state statutes.
It is common for health care organizations to have multiple data retention requirements, as not every type of data is treated equally. Different state and federal data retention laws may require an organization to keep data for a length of time ranging from a few years to more than two decades. Consult your organization's compliance or legal department if you are not sure.
Another part of the planning process involves deciding how and when data will be moved to the archives. Although some organizations opt to manually archive data, it is generally considered to be a better practice to use workflows to automate data lifecycle management.
Workflow analysis requires a lot of planning, since workflows are usually specific to individual data types. For example, a Microsoft SharePoint workflow might be perfectly adequate for moving old Microsoft Office documents to an archive, but such a workflow would not work for archiving e-mail messages.
In addition, when designing an archive system, it is important to consider your reasons for archiving data in the first place. For example, some organizations only archive data as a way of satisfying HIPPA retention requirements. In all likelihood, accessibility is not a concern, as nobody will ever look at the archived data again. Other organizations archive data as a way of freeing up space on their primary storage volumes.
An organization's reasons for archiving data should play heavily into the design of the medical image archive. For example, if your organization is only archiving data to satisfy regulatory mandates, then the archives should probably be designed in a way that prevents access to anyone other than auditors. If, on the other hand, your goal is to free up space on your main storage volumes, then you might want to design the medical image archive in a way that grants users read access to their archived data.
Even though archival data is unlikely to be accessed on a regular basis, fault tolerance should not be ignored, as the medical image archive needs to be reliable enough that data can be stored or retrieved on an as-needed basis. The only way to achieve this requirement for high availability is through the use of redundant hardware.
Likewise, archival data needs to be protected against loss. The federal government can impose stiff penalties for a health care data breach. As such, it's necessary to create a backup. While a tape backup strategy might seem like the obvious solution to backing up archive data, there are at least a couple of downsides to backing up your archives to tape.
First, health care organizations almost always purge archive data after a predetermined expiration period. This aspect of data lifecycle management is done in an effort to protect the organization. After all, data cannot be subpoenaed if it has been legally deleted after the required retention period expires. However, backing up the archives to tape can undermine the legal destruction of data, since data that has been purged may continue to exist on backup tapes.
Another down side to using tape backup is that there is a potential for data loss if tapes are lost or damaged. Data loss can also occur if the archive system is damaged before data can be backed up to tape.
Because tape backups are not an ideal solution for protecting archive systems, you might be better off replicating your archives to one or more off-site servers. That way, the archives are protected in real time, and you don’t have to deal with the hassles of tape.
In conclusion, designing an on-site medical archive is not a process to be taken lightly. The most effective way to design an archival system is to have a clear understanding of your goals and then work through the design process with those goals in mind.
Brien M. Posey, MCSE, is a Microsoft Most Valuable Professional for his work with Windows 2000 Server and IIS. He has served as CIO for a nationwide chain of hospitals and was once in charge of IT security for Fort Knox. Write to him at firstname.lastname@example.org contact @SearchHealthIT on Twitter.
This was first published in March 2012