One of the many ways health care has changed over the decades has been not only in the way it’s delivered, but by whom.

A national shortage of physicians, especially in rural areas, has, in part, been the propelling force behind this change. By necessity, some categories of care are being handled by providers with credentials that are supportive of, but not equivalent to, an M.D. degree.

Hawaii needs to work within the current reality to close its own gap in care. It’s particularly a concern on the neighbor islands, where the number of specialists and even primary care physicians falls short of what’s needed to meet the needs of a growing population.

That’s why a proposal by state Sen. Josh Green to encourage the local training of physician assistants (PAs) makes sense. There are existing programs with which Hawaii could form a partnership and ramp up quickly.

Green, who represents Kailua-Kona to Naalehu and is himself a practicing physician in West Hawaii, has a built-in preference for establishing the program on Hawaii island. There is an objective logic to that, considering the distances separating rural populations from urban services compound the effect of a provider shortage on the Big Island.

Wherever it’s established, though, having medical providers “home grown” on a neighbor island should help in staffing more remote locations with professionals who prefer neighbor island living, or are acclimated to it.

Green is discussing prospects for such a partnership with the University of Washington, concerning its MEDEX Northwest Physician Assistant Program. Its program, he said, is oriented around recruitment and training PAs with the specific goal of countering the doctor shortage.

He also said he plans to introduce a bill in the next legislative session to offer physicians a tax credit of $50,000 a year for two years when they hire a physician assistant or nurse practitioner to practice primary care. That should reinforce the efforts to lure practitioners to Hawaii, which faces a particularly tough recruitment challenge when competing with communities that have a considerably lower cost of living.

In a separate but complementary development, the University of Hawaii at West Oahu broke ground Monday on its long-awaited administration building.

The $36 million facility, comprising 43,000 square feet of office and classroom space, represents another front in the drive to fulfill Hawaii’s unmet health care needs because it will accommodate the Kapolei campus’ “allied health” programs.

Students working in these new laboratories will be trained for positions in long-term care, community health and other industries. Although not frequently a focus in discussions of provider shortages, these support-service professionals are key to building a more robust system overall.

The success of health-care systems increasingly will depend on better outreach and preventive services of the kind that allied-health programs provide. And long-term care ranks among the most critical needs, as Hawaii, and the rest of the nation, continues to age.

The statistics paint a picture that has policymakers worried, and rightfully so.

According to a report prepared for the 2015 Legislature by the UH medical school’s Hawaii Physician Workforce Assessment Project, a best-case scenario projects that the state will have a full-time equivalent shortage of 800 physicians by 2020.

Another study, by the research institute, the Robert Graham Center, forecasts a shortage of 318 doctors, just in the primary-care category, by 2030.

That is not far in the future at all, and action must be taken swiftly. There are various strategies that all could play a part in the solution. A physician assistant training program should be part of the prescription.