Hawaiʻi Island Has Enough Mammography Machines. What It Does Not Have Is a Way to Reach Them.

Hawaiʻi Island has more certified mammography facilities per resident than Oʻahu. It has 28 times fewer per square mile. Five facilities, three towns, 4,028 square miles. The shortage is reach.

HHTF Staff · 2026-08-11

Hawaiʻi Healthcare Task Force · Op-Ed

By David Isei, MPH, MAOL, PMP Executive Director, Hawaiʻi Healthcare Task Force

Published August 11, 2026. Written against the Task Force's v5 evidence brief, the first analysis of this question measured on Hawaiʻi Island rather than borrowed from the mainland.

The instinct in Hawaiʻi, when a rural health number looks bad, is to reach for the words we already have. Shortage. Underserved. Health desert. Those words are not wrong, but they are imprecise, and the imprecision costs us at the Legislature every session. Breast cancer screening on Hawaiʻi Island is a good example of why the specific version of the story matters more than the general one.

Here is the specific version, measured against the actual county.

2.49 facilities per 100,000 residents on Hawaiʻi Island, versus 2.07 on Oʻahu

28x fewer facilities per square mile than Oʻahu

5 certified facilities for the entire county, in three towns

26 communities measured, covering 199,855 residents

The facility paradox

Hawaiʻi Island has more federally certified mammography facilities per resident than Oʻahu does. On a facilities-per-100,000 basis, the county's figure is 2.49. Oʻahu's is 2.07. On the standard measure, the machines are not the problem.

They become the problem when you measure them against geography instead of against people. Hawaiʻi Island has 1.24 certified facilities per 1,000 square miles. Oʻahu has 34.96. That is a twenty-eight-fold difference in reachability, and the ratio understates the gap, because two of Oʻahu's facilities sit on military installations and are not open to the general public.

Figure 1 · The same five facilities, measured two ways

Per person, Hawaiʻi Island looks adequate. Per square mile, it does not.

Certified facilities per 100,000 residents

Hawaiʻi Island 2.49

Oʻahu 2.07

Certified facilities per 1,000 square miles

Hawaiʻi Island 1.24

Oʻahu 34.96

Source: complete enumeration of FDA Mammography Quality Standards Act certified facilities in Hawaiʻi, retrieved by direct query of the FDA Mammography Facility Database on August 11, 2026. Statewide total 33: Oʻahu 21, Hawaiʻi Island 5, Maui County 5, Kauaʻi 2. Denominators are 2020 Census land area and resident population. The FDA list counts facilities, not imaging units or annual throughput.

Five facilities serve the entire county. Two in Hilo, two in Kailua-Kona, and one in Kamuela. Every other community on 4,028 square miles of island drives to one of those three towns.

The shortage is not machines. It is reachable machines.

The first Hawaiʻi measurement of what distance does

Until now, every quantified estimate of how much distance depresses mammography participation came from continental United States Medicare claims or from a Danish national screening programme. Hawaiʻi advocacy has borrowed those figures for a decade. The Task Force can now report the first measurement taken in Hawaiʻi.

Across all 26 ZIP Code Tabulation Areas on Hawaiʻi Island, using CDC PLACES small-area estimates of screening participation and great-circle distance from each community's population centroid to the nearest certified facility, screening falls as distance rises. The correlation is r = -0.50 (p = 0.010). The slope is 0.068 percentage points of screening lost per additional mile, and 0.088 points per mile when weighted by population (p = 0.005).

Figure 2 · Every community on Hawaiʻi Island, plotted

Circle size is population. Colour is what the community actually has. Hover any circle for its name and numbers.

Hilo: 73.0% screened, 0 miles to a facility, 46,615 residents, physician and health centre Kailua-Kona: 74.0% screened, 0 miles to a facility, 38,234 residents, physician and health centre Waimea: 75.0% screened, 0 miles to a facility, 13,339 residents, physician and health centre Hōlualoa: 75.1% screened, 3 miles to a facility, 4,094 residents, private physician only Papaʻikou: 72.3% screened, 5 miles to a facility, 1,670 residents, physician and health centre Keaʻau: 71.8% screened, 8 miles to a facility, 20,503 residents, physician and health centre Pepeʻekeo: 70.6% screened, 8 miles to a facility, 2,222 residents, no physician, no health centre, no billing Kurtistown: 71.5% screened, 8 miles to a facility, 3,923 residents, no physician, no health centre, no billing Kealakekua: 73.8% screened, 9 miles to a facility, 3,806 residents, physician and health centre Waikoloa: 75.5% screened, 10 miles to a facility, 7,447 residents, health centre only Captain Cook: 74.2% screened, 11 miles to a facility, 6,818 residents, physician and health centre Mountain View: 71.2% screened, 12 miles to a facility, 8,483 residents, no physician, no health centre, no billing Hakalau: 71.8% screened, 13 miles to a facility, 650 residents, no physician, no health centre, no billing Honokaʻa: 72.8% screened, 14 miles to a facility, 4,990 residents, physician and health centre Nīnole: 73.9% screened, 16 miles to a facility, 412 residents, private physician only Kapaʻau: 73.5% screened, 17 miles to a facility, 3,613 residents, physician and health centre Pāhoa: 68.8% screened, 18 miles to a facility, 14,687 residents, physician and health centre Hāwī: 74.5% screened, 18 miles to a facility, 2,020 residents, private physician only Papaʻaloa: 71.7% screened, 19 miles to a facility, 548 residents, no physician, no health centre, no billing Paʻauilo: 71.5% screened, 20 miles to a facility, 1,782 residents, no physician, no health centre, no billing Laupāhoehoe: 72.0% screened, 20 miles to a facility, 649 residents, health centre only Volcano: 71.6% screened, 21 miles to a facility, 4,125 residents, no physician, no health centre, no billing ʻOʻōkala: 71.2% screened, 24 miles to a facility, 281 residents, no physician, no health centre, no billing Ocean View: 71.4% screened, 40 miles to a facility, 4,806 residents, mobile unit only Pāhala: 69.5% screened, 44 miles to a facility, 1,559 residents, physician and health centre Nāʻālehu: 71.8% screened, 48 miles to a facility, 2,579 residents, physician and health centre Waikoloa Pāhoa Ocean View Hilo Kailua-Kona Nāʻālehu 68% 70% 72% 74% 76% 0 10 20 30 40 50 Miles to nearest FDA-certified mammography facility Women 50 to 74 screened in past 2 years (%)

No care of any kind Mobile unit only Private physician only Health centre only Both

Cross-sectional ecological analysis, n = 26 ZCTAs. Outcome is the CDC PLACES 2024 MAMMOUSE measure. The shaded band is the 95% confidence interval on the fitted slope. This describes communities and not individuals, and no causal claim is made.

Read plainly: a community 40 miles from the nearest facility sits about 2.7 percentage points lower in screening participation than an otherwise similar community next door to one. Ocean View is that community. Pāhoa is the community that shows what happens when a shortage of primary care compounds it, at 68.8 percent screening participation, the lowest recorded rate for any named place on the island.

Both barriers are real, and they are independent

The other thing our earlier work could not say cleanly is now sayable. When distance and the presence of any local primary care are entered into the same statistical model, neither one absorbs the other.

Figure 3 · Adjusted model, both terms entered together

Each bar is the estimated effect. The line through it is the 95% confidence interval. Neither crosses zero.

Each additional mile of distance

-0.067 percentage points · 95% CI -0.112 to -0.023 · p = 0.005

no effect

Having any local primary care, versus none

+1.55 percentage points · 95% CI +0.37 to +2.72 · p = 0.012

no effect

43%

of the variation in screening participation across the county, explained by these two variables together

The important word in that finding is additive . The two barriers are separate, and the communities carrying both carry both independently. This is a smaller and more honest claim than the multiplicative "cascade" language that health advocacy tends to reach for, and it is the version that will survive scrutiny.

What the federal government already says

The entire county is designated by HRSA as a single geographic primary care Health Professional Shortage Area, record 1153185595, designated in 2019 and last reviewed in September 2025.

Figure 4 · Hawaiʻi County against the federal target

The county carries 1,510 more residents per primary care clinician than the federal goal allows.

Hawaiʻi County, actual 5,010 : 1

Federal target ratio 3,500 : 1

Residents per available primary care clinician. Lower is better.

HRSA Health Professional Shortage Area record 1153185595, retrieved August 11, 2026. Designation population 200,968. Estimated underserved population 60,583. Additional clinicians needed to lift the designation, 17.31 full-time equivalents.

Field Value

Designation type Geographic HPSA, single county, rural

HPSA score 15

Designation population 200,968

Population to provider ratio 5,010 : 1

Federal target ratio 3,500 : 1

Estimated underserved population 60,583

Additional clinicians needed 17.31 full-time equivalents

Percent of need met 69.9%

One piece of arithmetic discipline is worth naming, because it comes up in advocacy material all the time. The statewide figure for percent-of-need-met is 66.6 percent. Hawaiʻi County's own figure is 69.9 percent, which is better than the statewide number. Quoting the scarier statewide figure as though it described this county is the kind of small error that costs a coalition its credibility the first time a legislator's staff checks it. The case does not rest on that number. It rests on the ratio, 5,010 residents per available primary care clinician against a federal goal of 3,500 to 1, and on the fact that the entire county carries the designation.

The blind spot we now know how to size

Any claims-based provider count in this state is a floor rather than a total, because Medicare Advantage encounters do not appear in the public claims file. That limitation used to be a qualitative footnote. It can now be sized.

Figure 5 · How much of Hawaiʻi County's Medicare population the public claims file cannot see

Calendar year 2025. Each block is roughly 531 beneficiaries.

48.4% of beneficiaries the public claims file cannot see 53,142 Medicare beneficiaries, Hawaiʻi County, 2025 In Medicare Advantage, invisible to public claims (25,735) Original Medicare, visible (27,407)

CMS Medicare Monthly Enrollment, calendar year 2025. Hawaiʻi County penetration 48.4 percent. For comparison, Honolulu 54.6 percent, Maui 56.5 percent, Kauaʻi 49.1 percent.

Nearly half. Every activity-based provider count in this state's advocacy work should be read with that caveat sitting on the page rather than buried in a footnote.

The remedies are not what "shortage" usually implies

The facility paradox splits the policy ask cleanly, because capital and transport are different remedies.

The county does not need more mammography machines. It needs mobile capacity, screening transport, and, above all, more primary care clinicians positioned in the communities that currently have none. Nationally, women with a personal health care provider are screened at 79.1 percent versus 42.2 percent for those without, and our own model confirms the direction of that finding on this island at the community level. A referral requires someone to write it.

Three levers deserve intent this session, all of them already existing federal or state instruments.

1 Prioritize Hawaiʻi County placements in the National Health Service Corps Loan Repayment Program

The whole county is HPSA-designated. The eligibility is not the question. The intensity of placement is.

2 Fund a rural residency training program through HRSA's Rural Residency Planning and Development grant, sited on Hawaiʻi Island

Family medicine is the specialty most directly upstream of the mechanism this brief describes. The state has never hosted an RRPD-funded program on a neighbor island.

3 Establish a primary care spending floor in state law

Benchmarked against the Milbank State Primary Care Investment framework. The United States spends 5 to 7 percent of health care dollars on primary care. The OECD average is 14 percent. Rhode Island, Oregon, and Delaware have written a floor into statute. Hawaiʻi has not.

The honest close

Everything above was measured on the ground, in this county, using public federal data and published methodology. The full brief with the plots, the confidence intervals, the query dates, and the community-by-community data table is available to any legislator, journalist, or clinician who wants to check the work.

The Task Force is not asking the Legislature to accept a projection. It is asking the Legislature to accept an arithmetic that is now, for the first time, taken in the place it applies to. Hawaiʻi Island has enough mammography facilities per resident. It does not have enough of them within reach, and it does not have the primary care clinicians positioned to send women to the ones that exist. Those are two different problems and both are now measured.

The evidence base does not have to be argued anymore. It only has to be acted on.

Truth in the data. Care in the community.

HHIP

Hawaiʻi Healthcare Intelligence Platform

Every measurement in this article was produced on HHIP, the Task Force's data platform, at hawaiihip.org . Evidence brief v5 was published August 11, 2026. Every figure comes from a public federal source queried on a stated date, and every computation is scripted, reproducible, and available to anyone who ask