Ambulatory Care Use - Washington State Hospital Association

September 2010
Outpatient Series:
Ambulatory Care Use

Washington State Hospital Association
Ambulatory Care Use:
What Can Be Learned from Western
Washington
Developed by WSHA’s Health Information Program
For information contact:
Jim Cannon, Executive Director, Health Information Program
jimc@wsha.org or (206) 216-2551
Jane Feldman, Director, Analytic Services, Health Information Program
janef@wsha.org or (206) 216-2505
September 2010

Table of Contents
1. Introduction
2. Geographic Classification System
3. Utilization Rates: Overall, Urban, and Non-Urban
4. Outpatient Utilization Trends and Utilization by Care Setting
6. Regional Variation by Setting of Care
7. Utilization Rate Variation by Region
8. Variation by Procedure: CT Scan
9. Variation by Procedure: MRI and Nuclear Medicine
10. Variation by Procedure: Musculoskeletal and Arthroscopy
11. Variation by Procedure: Digestive System and Colonoscopy
13. Conclusion
Appendix 1: Methodology
Appendix 2: CPT Codes
Appendix 3. Data Suppliers
Appendix 4. Zip Codes

Introduction
WSHA Ambulatory Care Report
The Outpatient Series
Ambulatory care service use is growing, but data about it are in short supply. Changes in outpatient services
are causing hospitals to shift resources to adapt to changing care delivery. Currently, hospitals have few tools
to plan for outpatient services or determine market share. To date there has not been a reliable source for
ambulatory use rates in Washington State.
For several years, at the request of its members, the Washington State Hospital Association’s Health Information
Program (HIP) has worked to develop sources of outpatient information. This report is a result of those
efforts and summarizes the association’s first successful acquisition of ambulatory use information. Currently,
there is no outpatient equivalent to the state’s inpatient data set. The association, however, was able to secure
ambulatory care utilization data through a request to the Puget Sound Health Alliance. The Alliance is a regional
partnership working to improve quality and efficiency of health care in five western Washington counties (King,
Kitsap, Pierce, Snohomish and Thurston). Alliance members include employers, patients, health plans, physicians,
hospitals, and government.
This fi rst report is limited to only a portion of the state due to limitations of the data source. In the coming
months, HIP will release statewide reports on outpatient use by the Medicare population and on the use of
emergency department services. To ensure that future reports meet your needs, please take a few minutes to
complete the six question online survey at https://www.surveymonkey.com/s/outpatientreport1.
This Report
For this initial report, summary information is discussed from the Alliance data set for three broad service lines:
total radiology services, digestive system procedures, and musculoskeletal procedures. Within these service
lines, five specific services are discussed: computed tomography (CT), magnetic resonance imaging (MRI),
and nuclear medicine for radiology services, colonoscopies for digestive system procedures, and arthroscopies
for musculoskeletal services. These services were selected because many of them are provided in non-hospital
ambulatory settings and they represent a wide array of outpatient services. Service lines were defined by CPT
code, as listed in Appendix 2.
Based on the association’s request, the Alliance provided a series of detailed data reports. The claims data set
used in this analysis includes all paid claims from fourteen health insurers and large, self-funded employers
from January 1, 2006 through June 30, 2008. It is the only source of local information about outpatient use
currently available to providers, payers, and the public. The data represent complete utilization profiles for
more than two million residents of western Washington. The data set includes 2.26 million lives in 2006, 2.30
million in 2007, and 2.08 million in 2008.
September 2010 1

WSHA Ambulatory Care Report
An important caveat must be kept in mind when examining this report’s findings. Since Medicare claims are
not included in the data set, the information primarily reflects an under age 65 population. Only about five percent
of the data is from people age 65 and above.
Even without the Medicare population, the information is a rich resource for planning and policy purposes. It
represents the first-ever analyses of local ambulatory care utilization rates and trends, and gives a much more
precise and valid picture of these rates and trends than has been possible using national data sources or data
from a single insurer. Further, the level of local area detail allows examination of in- and out-migration patterns
for specific service lines, in both hospital-based and non-hospital outpatient care.
This report includes an overview analysis of the data available. In the coming weeks, HIP will make the detailed
data tables available for further analysis through the WSHA web site.
Geographic Classification System
Rates presented in this report are defined per 1,000 covered lives, with a reminder that these lives are almost
all in the under-age 65 population. Rates are based upon the residence of the beneficiary, not where service is
provided. Each ambulatory care service is linked both to the area in which it was provided and to the health
service area of the patient receiving the service. Health service areas are aggregated into five regions, as illustrated
in the map below. This report is limited to the five region area as a result of limitations of the data source.
It focuses on these regions, though more detailed information is available by county and by sub-county areas.
Statewide reports from other data sources will be produced in the coming months.
San
Juan
Whatcom
Skagit
Everett Region
Clallam
Snohomish
Seattle Region
Jefferson
Kitsap
King
Tacoma Region
Grays
Harbor
Mason
Olympia Region
Thurston
Pierce
Other Western Washington
Pacific
Lewis
September 2010 2

Findings
WSHA Ambulatory Care Report
Overall Rates
This chart summarizes the 2008 use rates for the eight services discussed in this report. In several areas the
range between highest and lowest regional rate is relatively small; it is more significant in CT scans and
digestive system procedures.
Utilization Rates for All Ambulatory Care Settings
per 1,000 Covered Lives - 2008
Western WA Lowest Regional
Rate
Highest Regional
Rate
Total Radiology 655.0 648.0 (Tacoma) 679.1 (Everett)
CT Scans 81.0 67.6 (Olympia) 86.8 (Everett)
MRIs 41.7 38.6 (Olympia) 46.0 (Everett)
Nuclear Medicine 16.9 16.2 (Seattle) 20.0 (Tacoma)
Digestive System 71.0 55.4 (Everett) 73.4 (Seattle)
Colonoscopies 19.8 17.9 (Tacoma) 20.6 (Seattle)
Musculoskeletal System 64.6 61.6 (Seattle) 74.2 (Olympia)
Arthroscopies 1.8 1.6 (Olympia) 2.0 (Everett)
Urban Rates
The rates and findings presented above may be applicable to other urban regions in Washington State as the
findings are based on Washington practices and may be more relevant than other estimates including the publicly
available utilization estimates derived from Medicare data (such as the Dartmouth Atlas).
Non-Urban Rates
Currently, there is limited information available through the Alliance that relates specifically to non-urban
areas. Of the four regions studied, Everett and Olympia include large non-urban areas, although the bulk of
the population is concentrated in the urban area for which the region is named. However, a few key findings for
non-urban areas are noteworthy:
• Use rates for ambulatory care services are not dramatically different for non-urban areas compared to
more urbanized areas. It should be reassuring to non-urban providers that most local residents remain
local for outpatient services. For common service lines, if there is service availability, individuals tend to
stay close to home.
• More-urban areas have a higher percentage of hospital-based procedures than less-urban areas for the
eight service lines examined in this report. This is somewhat surprising, as the local hospital is often
the major service provider in non-urban areas.
• There is out-migration to urban areas for more complex services, often because the service is not
offered in non-urban areas.
September 2010 3

Outpatient Utilization Trends
WSHA Ambulatory Care Report
While rates of change varied among specific service lines, all had modest increases in 2007 and considerably
higher rates for the first half of 2008. This was true for annual use rates in all service lines and nearly all
geographic areas. This finding was consistent across the eight service lines examined.
An example of the considerable increase seen in 2008 is demonstrated in the graph below. For total
ambulatory radiology, there was a slight increase observed in 2007 (up 2.6 percent from 2006 use rates),
followed by a much larger increase in the first half of 2008 (where use rates were 16.1 percent higher than in
2007). Use rates for selected ambulatory surgical procedures also increased over time, but the increases were
not as large as for radiology. This finding is consistent with national data showing hospitals gaining market
share in diagnostic imaging, especially MRIs. One study of Medicare claims data showed a tripling of MRI
procedures between 1995 and 2005. The study also found CT procedures more than doubled over the same
time period.
Rate per 1,000 Covered Lives
680
660
640
620
600
580
560
540
520
500
480
Total Ambulatory Care Radiology Use Rate
Change Over Time - Puget Sound Region
2006 2007 2008 (est.)
Outpatient Utilization by Setting of Care
In the Western Washington area, more outpatient care in the services examined is being provided in hospitals
than in non-hospital settings. The one exception is colonoscopies where more services were provided in
non-hospital settings. Some regional exceptions to this finding are probably based on service capacity. The
chart on the next page summarizes the 2008 distribution of hospital versus non-hospital settings by service line.
These findings appear to be very stable over time.
September 2010 4

WSHA Ambulatory Care Report
Ambulatory Utilization Rates by Service Line, Setting, and Year
Procedures per 1,000 covered lives (under 65 population) - total Western Washington
Service Line 2006 2007 Estimated 2008
Hospital
Nonhospital
Total Hospital Nonhospital
Total Hospital Nonhospital
Musculoskeletal 29.39 28.31 57.52 29.89 28.22 58.11 34.76 29.81 64.57
System
Arthroscopies 0.82 0.66 1.48 0.79 0.75 1.54 1.02 0.77 1.79
Digestive System 42.44 18.46 60.91 44.09 19.52 63.61 48.83 22.17 71
Colonoscopies 6.87 9.56 16.42 6.94 10.46 17.41 7.85 11.91 19.76
Total Radiology 361.68 188.16 549.85 371.25 192.93 564.18 440.97 214.02 654.99
CT Scans 54.74 11.07 65.81 57.84 11.75 69.59 68.24 12.8 81.04
MRIs 21.04 14.25 35.3 21.43 15.04 36.47 25.12 16.54 41.66
Nuclear Medicine 11.48 3.53 15.01 11.42 3.74 15.16 12.82 4.1 16.92
Total
The split between hospital and non-hospital use rates varies by type of procedure. Almost half (46 percent) of
all ambulatory care musculoskeletal procedures are performed in non-hospital settings, while more than two
thirds of ambulatory care digestive system procedures are performed in hospitals. The chart above presents
rates over time and by setting for specific service lines.
The complexity and capital demands of a procedure appear to factor into the setting where a procedure is
performed. While the bulk of digestive system procedures are performed in hospital-based settings,
colonoscopies, a relatively simple procedure with low capital requirements, were more likely to occur in nonhospital
settings. Conversely, the majority of radiology services were provided in hospital-based settings,
particularly for the services requiring high cost radiology equipment such as CT or MRI.
Three radiology service lines (CT scans, MRIs, and nuclear medicine) account for about 24 percent of the
hospital-based total radiology services. These three service lines make up only 15 percent of the total nonhospital
ambulatory radiology services, where less capital-intensive radiology services (simple x-rays, for
example) are the bulk of radiology services performed. While this finding is expected, the number of
capital-intensive services performed in non-hospital settings is somewhat surprising.
September 2010 5

WSHA Ambulatory Care Report
90%
Percent of Ambulatory Care Procedures That Were Hospital Based - 2008
80%
70%
60%
50%
40%
30%
20%
10%
0%
Total Radiology CT Scans MRIs
Nuclear
Medicine
Musculoskeleta
l System
Arthroscopies
Digestive
System
Colonoscopies
Percent 67% 84% 60% 76% 54% 57% 69% 40%
Differences in percentage of services by setting can be seen graphically on the chart above. The data graphed
are for 2008, but there was almost no change over time in these hospital-based percentages.
Regional Variation by Setting of Care
While there was consistency over time in percent of procedures performed in a hospital versus a non-hospital
setting, there was considerable variation among regions. More urbanized areas had a higher percentage of
hospital based procedures.
90%
Percent of Ambulatory Care Procedures Which Were Hospital-Based - by Region, 2006
80%
70%
60%
50%
40%
30%
20%
10%
0%
Total Radiology CT Scans MRIs Nuclear
Medicine
Musculoskeletal
System
Arthroscopies Digestive System Colonoscopies
Overall Everett Olympia Seattle Tacoma
September 2010 6

Utilization Rate Variation by Region
WSHA Ambulatory Care Report
Across all regions, the use of ambulatory services is increasing. However, use rates varied among regions.
For radiology services, regional variation has increased between 2006 and 2008. In 2006, minimal variation
existed in CT procedures, MRI or nuclear medicine.
• For CT procedures in 2008, the Olympia region use rate was 16 percent lower than the overall average,
and 22 percent lower than the Everett and Tacoma regions.
• The Everett region’s MRI use rate was 10 percent higher than the average and 18 percent higher than the
Olympia and Tacoma regions in 2008.
• The Tacoma region’s use of nuclear medicine for 2008 was 18 percent higher than the overall average and
23 percent higher than the Seattle region.
In surgical procedures, regional variation appeared across time and procedures.
• In 2006, the Olympia musculoskeletal procedures rate was 30 percent higher than the overall average,
and the variation remained fairly consistent over the two year period.
• The Everett region had a 12 percent higher than average use rate of arthroscopy procedures. The region’s
use rate was 25 percent higher than the Olympia region.
• In 2008, the use rate for digestive system procedures in Seattle was 32 percent higher than in Everett and
15 percent higher than in Olympia or Tacoma.
A number of factors could account for this variation, including the opening of new facilities or differences in
availability of a service in a region.
Patient Migration Analysis - Sample
One of the strengths of these data is the ability to extract detailed information on patient migration across areas.
Patient migration would show where the patients from a given geographic area go to receive services. One
example, using Pierce County, is shown below. For 2007, only two thirds of Pierce County residents received
outpatient radiology in Pierce County.
Where Tacoma Health Service Area Residents
Dispersion of Ambulatory Care Radiology Services
Received
Tacoma
Ambulatory
Health Service
Care
Area
Radiology
Residents
Services
- 2007
- 2007
3%
3% 3% 6%
4%
14%
67%
Tacoma
Federal Way
Puyallup
Seattle North
Seattle Central
Olympia
All Other
September 2010 7

WSHA Ambulatory Care Report
Of the out-migrants, the most common destination was the Federal Way health service area, with the remainder
spread among destinations east, north, and south. Referral patterns for the two large health systems based in
the Tacoma region may be driving some of the observed out-migration, particularly to the Federal Way and
Puyallup health service areas. The above analysis also demonstrates the artificiality of county boundaries in
defining and evaluating patient migration patterns for receiving health services.
The Health Information Program can use the Alliance reports to create many permutations of this type of
analysis − information can be varied by year, service line, procedure, hospital-based versus non-hospital
settings, and health service area source and destination. The many options result in a very large number of
in- and out-migration analyses − a number far too large for inclusion in this overview. The example on the
previous page, however, is an indication of the unique power of the resource, providing an unprecedented
ability look at ambulatory care utilization patterns in western Washington. Similar analysis can be created using
the detailed data tables that will be available to members in the coming weeks.
Variation by Procedure
Radiology
CT Procedures
There was minimal variation in outpatient computerized tomography (CT) scan utilization rates among regions
in 2006, but by 2008 there was noticeable variation, especially in the Olympia region, where the use rate was 16
percent lower than the overall average and 22 percent lower than the Everett and Tacoma regions. The slower
growth in the Olympia region may be due to capacity constraints or other local factors. The other regions all
have similar use rates and similar growth patterns, suggesting the overall rate is the best one to use for planning.
Ambulatory Care CT Scan Utilization Rates
Variation by Region Over Time
Rate per 1,000 Covered Lives
100
90
80
70
60
50
40
30
20
10
0
2006 2007 2008 (est)
Overall
Everett
Olympia
Seattle
Tacoma
September 2010 8

WSHA Ambulatory Care Report
MRI Procedures
Again there was minimal variation in outpatient medical resonance imaging (MRI) utilization rates among
regions in 2006, by 2008 there was noticeable variation, especially the Everett region, where the use rate was
ten percent higher than the overall average and 18 percent higher than the Olympia and Tacoma regions.
Rate per 1,000 Covered Lives
50
45
40
35
30
25
20
15
10
5
0
Ambulatory Care MRI Utilization Rates
Variation by Region Over Time
2006 2007 2008 (est)
Overall
Everett
Olympia
Seattle
Tacoma
Nuclear Medicine Procedures
Some variation in outpatient nuclear medicine utilization rates was observed among regions, but the relatively
small number of procedures makes this variation appear larger than it actually is. By 2008, the Tacoma region
use rate was 18 percent higher than the overall average and 23 percent higher than the Seattle region. This
faster growth in the Tacoma region may be due to the opening of a new facility in the region.
25
Ambulatory Care Care Nuclear MedicineUtilization Utilitzation Rates
Variation by Region Over Time
Rate per 1,000 Covered Lives
20
15
10
5
Overall
Everett
Olympia
Seattle
Tacoma
0
2006 2007 2008 (est)
September 2010 9

Surgical
WSHA Ambulatory Care Report
Musculoskeletal Procedures (tendon repairs, dislocations, fracture repair, etc.)
Noticeable variation in outpatient musculoskeletal procedure utilization was observed among regions,
particularly for the Olympia region. In 2006, the Olympia use rate was 30 percent higher than the overall
average and 39 percent higher than the Seattle region. There was virtually no growth in the Olympia region rate
over the three year, however, and by 2008 growth in the other regions had somewhat reduced the variation.
Rate per 1,000 Covered Lives
80
70
60
50
40
30
20
10
0
Ambulatory Care Musculoskeletal Procedure Rates
Variation by Region Over Time
2006 2007 2008 (est)
Overall
Everett
Olympia
Seattle
Tacoma
Outpatient Arthroscopy Procedures
The utilization rate per 1,000 covered lives for outpatient arthroscopy is much smaller than for the other service
lines, but there were still more than 3,500 procedures in the study area each year. This means the data are
reliable. As seen in the graph, there is variation among the regions in the use rate, particularly for the
Everett region. In 2008, the Everett region use rate was 12 percent higher than the overall average and 25
percent higher than the use rate for arthroscopy procedures in Olympia.
2.5
Ambulatory Care Arthroscopic Procedure Rates
Variation by Region Over Time
Rate per 1,000 Covered Lives
2.0
1.5
1.0
0.5
Overall
Everett
Olympia
Seattle
Tacoma
0.0
2006 2007 2008 (est)
September 2010 10

WSHA Ambulatory Care Report
Outpatient Digestive System Procedures
(esophagus or stomach endoscopy, gallbladder removal, etc.)
Notable regional variation in outpatient digestive system procedure utilization rates was observed, particularly
for Olympia in the first two years and for Seattle and Everett in 2008. In 2008, the use rate in Seattle was 32
percent higher than in Everett and 15 percent higher than in Olympia or Tacoma. The marked reduction in the
Everett region for 2008 is worth further investigation. It is also interesting to note the degree to which the much
larger population in the Seattle region influences the overall average, as seen clearly in the 2008 data.
Rate per 1,000 Covered Lives
80
70
60
50
40
30
20
10
0
Ambulatory Care Digestive System Procedure Rates
Variation by Region Over Time
2006 2007 2008 (est)
Overall
Everett
Olympia
Seattle
Tacoma
Colonoscopy Procedures
There was steady growth in the use rate over time for all regions, but there was some variation in 2006
colonoscopy rates among regions. Over time, the rates for regions converged. By the first half of 2008 there
was only minor observed variation.
25
Ambulatory Care Colonoscopy Procedure Rates
Variation by Region Over Time
Rate per 1,000 Covered Lives
20
15
10
5
Overall
Everett
Olympia
Seattle
Tacoma
0
2006 2007 2008 (est)
September 2010 11

WSHA Ambulatory Care Report
Even where there does not appear to be much regional variation, such as for colonoscopies in 2007, the
underlying data often reveal considerable differences in the setting of care, as illustrated below. This chart
shows hospital-based and non-hospital outpatient utilization rates for colonoscopy procedures. In 2007, nearly
half of the outpatient colonoscopies in the Everett region were hospital-based, compared to only 25 percent in
the Olympia region. (Seattle had 42 percent hospital-based, and Tacoma had 36 percent hospital-based.) These
variations probably reflect the differences in regional service capability.
Rate per 1,000 Covered Lives
20
15
10
5
0
Outpatient Colonoscopy Procedure Rates 2007
Highlighting the Differences in Setting by Region
Everett Olympia Seattle Tacoma
Hospital-based
Non-Hospital
September 2010 12

Conclusion
WSHA Ambulatory Care Report
This report is the first opportunity HIP has had to analyze outpatient data. The Washington State Hospital
Association is continuing to develop additional resources for outpatient information. In the coming months,
statewide reports on outpatient services use by the Medicare population and an analysis of emergency department
use will be published. We hope the analysis presented here is a strong first step into helping members
understand how the residence of Washington are using ambulatory services and provides a powerful tool to plan
for the future.
Detailed data tables for each of the service lines will be made available to members in the coming weeks on the
WSHA web site. For more information about the findings presented in this report, please contact Jim Cannon,
executive director of the Health Information Program, at (206) 216-2551 or via e-mail at jimc@wsha.org. For
technical assistance, please contact Jane Feldman, director of analytic services, at (206) 216-2505 or janef@
wsha.org.
Jim Cannon
Executive Director, Health Information Program
Washington State Hospital Association
Jane Feldman
Director, Analytic Services, Health Information Program
Washington State Hospital Association
Special thanks to Thom Rees and Beth Zborowski for their work in the production of this report.
September 2010 13

Appendix 1: Methodology
WSHA Ambulatory Care Report
The information in this report is extracted from a set of outpatient utilization reports prepared earlier this
year by the Puget Sound Health Alliance. The Alliance’s reports were done at the request of the Washington
State Hospital Association’s Health Information Program. The outpatient reports were derived from the Alliance’s
comprehensive claims database of all paid claims from over two million residents of western Washington,
representing the claims from the 14 data suppliers (insurers and self-funded employers and trusts — see
Appendix 3).
The Alliance reports consist of detailed counts of ambulatory care services for eight service lines (defined by
ranges of CPT codes), indicating how many services or procedures were delivered each year in 30 health service
areas to residents of the 30 different health service areas. The result — for each year and service line — was a
30 by 30 grid of the count of services in each cell, separated into whether the service was delivered in a hospitalbased
or non-hospital setting. For example, one cell of the colonoscopy table for 2007 would include the number
of procedures performed in Central Seattle for residents of Bellingham, split into counts of hospital-based and
non-hospital procedures.
For any cell with fewer than ten observations in either setting category, the Alliance suppressed the data count in
order to preserve patient anonymity. The suppressed data are included in the Western Washington aggregate totals
for that year and service line. For all years and all service lines except arthroscopy, the suppressed data accounted
for less than 0.1 percent of the totals, meaning the rates calculated overall and by region are essentially unaffected
by data suppression. Due to the small number of arthroscopies, data suppression for this service line was about
one percent of the total in 2006 and 2007. For the half year of 2008, data suppression accounted for 2.5 percent
of the hospital-based services and 5.3 percent of the non-hospital services, for an overall 3.7 percent data suppression
for arthroscopies for the first half of 2008. This means that the actual rates of ambulatory care arthroscopies
are slightly understated at the regional level, especially for the first half of 2008.
September 2010 14

Appendix 2: CPT Codes
WSHA Ambulatory Care Report
Description
Ambulatory Care Outpatient Reports
Puget Sound Health Alliance - CPT Codes in Each Service Line
CPT-4 Code
Ranges
Description
CPT-4 Code
Ranges
Description
CPT-4 Code
Ranges
Musculoskeletal
System
20000-29999 Radiology 70010-79999 CT Scans 70450
70460
Arthroscopy 29805-29807 Nuclear 78000-79999 70470
29819 Medicine
70480-70482
29820 MRI 70336 70486
29822-29827 70540 70487
29834 70543-70545 70490
29835 70547 70491
29837 70548 70492
29838 70551-70553 70496
29846 71550 70498
29848 71555 71250
29862 72141 71260
29863 72142 71270
29870 72146 71275
29873-29384 72148 72125
29886-29888 72149 72126
29891 72156-72158 72128
29895 72195-72197 72129
29897 73218 72131
29898 73220-73223 72132
Digestive System 40490-49999 73718 72191-72194
73720 73200
Colonscopy 44388 73721-73723 73202
74181-74183 73700
44394 74185 73701
45378 75554 73702
45380 75556 74150
45381 76094 74160
45383 76393 74170
45384 76400 74175
45385 75635
45391 76070
45392 76360
76370
76376
76380
September 2010 15

Appendix 3: Data Suppliers
WSHA Ambulatory Care Report
Ambulatory Care Outpatient Reports
Puget Sound Health Alliance - Data Sources
2006 2007 2008
1. Carpenters Trust X X X
2. Community Health Plan X X X
3. City of Seattle X X X
4. DSHS - Medicaid Fee-for-Service X X X
5. First Choice Health Plan X X X
6. Group Health Cooperative X X X
7. Health Care Authority - UMP X X X
8. King County X X X
9. Molina Health Care X X X
10. Premera X X X
11. REI X X X
12. Retail Drugs Trust X X X
13. Snohomish County X X X
14. Teamsters Trust X X X
September 2010 16

Appendix 4: Zip Codes
WSHA Ambulatory Care Report
Puget Sound Health Alliance - Regions
Dartmouth Atlas Zip Code Definitions
Everett Region
Health
Service Area
Anacortes
10 Zip Codes
Arlington
3 Zip codes
Coupeville
7 Zip Codes
Everett
16 Zip Codes
Zip
Code
98221
98222
98243
98245
98250
98261
98279
98280
98286
98297
98223
98241
98259
98236
98239
98249
98253
98260
98277
98278
98201
98203
98204
98205
98206
Monroe
7 Zip Codes
Mount Vernon
16 Zip Codes
Olympia Region
Health
Service Area
Centralia
17 Zip Codes
98224
98251
98256
98272
98288
98293
98294
98232
98233
98235
98237
98238
98255
98257
98263
98267
98273
98274
98282
98283
98284
98287
98292
Zip
Code
98522
98531
Morton
4 Zip Codes
Olympia
25 Zip Codes
98336
98356
98361
98377
98501
98502
98503
98504
98505
98506
98507
98508
98509
98511
98512
98513
98516
98530
98540
98541
98556
98557
98559
98576
98579
98583
98589
98597
Seattle Region
Health Service
Area
Aberdeen
18 Zip Codes
May be reclassified
into other
western
Washington
(rural)
Auburn
4 Zip codes
Bellevue
18 Zip Codes
Zip
Code
98520
98526
98535
98536
98537
98547
98550
98552
98560
98562
98563
98566
98569
98571
98575
98587
98590
98595
98001
98002
98047
98071
98004
98005
98006
98207
98532
98599
98007
98208
98213
98533
98538
Shelton
4 Zip Codes
98548
98555
98008
98009
98252
98539
98584
98014
98258
98542
98592
98015
98270
98271
98544
98564
South Bend
5 Zip Codes
98527
98554
98024
98027
98275
98565
98561
98029
98290
98568
98577
98039
98291
98570
98586
98045
98296
98572
98050
98582
98053
98585
98065
98591
98074
September 2010
98596
98075

Appendix 4: Zip Codes Continued
WSHA Ambulatory Care Report
Bellingham
18 Zip Codes
May be
reclassified
into other
western
Washington
(rural)
Bremerton
27 Zip Codes
May be reclassified
into other
Western
Washington
(rural)
98220
98225
98226
98227
98228
98229
98230
98231
98240
98244
98247
98248
98262
98264
98266
98276
98281
98295
98310
98311
98312
98314
98315
98322
98337
98340
98342
98345
98346
98353
98364
98366
98367
98370
98378
98380
98383
98384
98386
98392
98393
98524
98528
98546
98588
Edmonds
7 Zip Codes
Enumclaw
4 Zip Codes
Federal Way
5 Zip Codes
Forks
3 Zip Codes
May be
reclassified
Kirkland
8 Zip Codes
Port Angeles
8 Zip Codes
May be
reclassified
into other
Western
Washington
(rural)
Port Townsend
7 Zip Codes
May be
reclassified
into other
western
Washington
(rural)
98020
98026
98036
98037
98043
98046
98087
98010
98022
98051
98092
98003
98023
98054
98063
98093
98305
98331
98350
98019
98033
98034
98052
98072
98073
98077
98083
98324
98326
98343
98357
98362
98363
98381
98382
98320
98325
98339
98358
98365
98368
98376
Renton
13 Zip Codes
Seattle Central
33 Zip Codes
98025
98030
98031
98035
98038
98042
98055
98056
98057
98058
98059
98064
98089
98040
98061
98101
98102
98104
98106
98108
98109
98110
98114
98116
98118
98119
98121
98122
98124
98126
98129
98134
98136
98139
98141
98144
98154
98161
98164
98170
98174
98181
98184
98191
98194
Seattle North
24 Zip Codes
Seattle South
19 Zip Codes
98011
98012
98021
98028
98041
98082
98103
98105
98107
98111
98112
98115
98117
98125
98127
98133
98145
98155
98160
98165
98175
98177
98185
98195
98013
98032
98062
98070
98113
98131
98132
98138
98146
98148
98151
98158
98166
98168
98171
98178
98188
98190
98198
98199
September 2010 18

Appendix 4: Zip Codes Continued
WSHA Ambulatory Care Report
Tacoma Region
Health Service
Area
Zip
Code
Tacoma
49 Zip Codes
98327
98354
98387
98445
98447
98450
Puyallup
23 Zip codes
98304
98321
98388
98401
98455
98460
98323
98402
98464
98328
98403
98465
98330
98404
98466
98338
98405
98467
98344
98406
98471
98348
98407
98477
98352
98408
98481
98355
98409
98492
98360
98411
98493
98371
98412
98497
98372
98413
98498
98373
98415
98499
98374
98416
98558
98375
98418
98580
98385
98421
412 Zip Codes Defined
98390
98422
98391
98424
98396
98430
98397
98431
98398
98433
98446
98438
Gig Harbor
10 Zip Codes
98303
98329
98439
98442
98332
98443
98333
98444
98335
98349
98351
98359
98394
98395
September 2010 19