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VISN 20 Patient Directory

The following reports on a VISN 20 Patient Directory built from the patient file (2) of 8 VistAs: Anchorage [463], Boise [531], Portland [648], Roseburg [653], Puget Sound [663], Spokane [668], Walla Walla [687], White City [692]. Together they hold 1,438,261 distinct patients using 1,920,002 patient file records.

Patient Breakdown

The directory holds 1,438,261 patients. 84.09% are Male and nearly all have Integration Control Numbers (ICN) and Social Security Numbers (SSN). 34.05% are marked deceased in at least one VistA holding part of their medical records. Note that 5.64% of patients are also VistA users.


The graph below shows the total number of patients in each system as well as a breakdown of whether those patients are unique to that system (exclusive), in some but not every other system (some) or in every other (all) systems in the directory. Unlike the equivalent graph for user directory, this seems to show that systems big and small have similar proportions of unique and shared patients, but they don’t.


The percentage view makes it clearer that smaller systems such as Walla Walla (WWW) through Roseland (ROS) have proportionately far more shared patients than their larger peers such as Puget Sound (PUG) or Portland (POR). This may be due to interfacility-consult work where a larger facility performs care for the patients of a smaller peer or because patients must go to bigger institutions for specialized care.


Patient Additions over Time

The following shows Daily Patient Addition for the last full three months for which data is available with Mondays marked on the X-axis. As expected addition “dances” up on weekdays and down on weekends which show little activity. For every system but Puget (PUG), holidays (1/20, 2/17) act like weekends. In contrast with the User Directory, this directory’s additions mirror system size - Puget exceeds Portland (POR), all the way down the smallest, Walla Walla (WWW).


Here are the yearly trends using a “365 day rolling mean” starting when the directory first gets data to the latest additions. Again, additions follow system size but first in 2000 and then in 2009, Puget and Portland jump up in volume compared to their smaller peers with Puget’s magnitude of increase exceeding Portland’s. Except for Roseland, which seems to follow its own way. The reason for this - new types of care or additional clinics supported in systems? - should be investigated.


A monthly resample from 2018 to the latest common date echo’s the yearly trends - unlike for User Directory, there are no unpredicted peaks or troughs.


Finally, a simple side by side set of totals for the last five years shows all systems adding similar numbers, year after year. It also reiterates that the bigger the system, the more patient additions it has - Puget adds up to 25,000 patients per year while Walla Walla adds less than 4,000.


VistA Clone Details

Data from 8 VistAs was parsed. The VistAs are copies of production VistAs cut on the dates given below …

# VistA Station # Clone Cut Date
1 Anchorage 463 2021-01-06
2 Boise 531 2021-05-08
3 Portland 648 2021-02-12
4 Roseburg 653 2021-05-09
5 Puget Sound 663 2021-02-16
6 Spokane 668 2021-05-10
7 Walla Walla 687 2021-04-18
8 White City 692 2021-05-08