The mission of any medical system ought to be timely delivery of care needed to maintain or restore good health. A recent change in procedure by the state’s largest health insurer raises concern, and patients need assurance that this objective can be met.

The Hawaii Medical Service Association, which insures 720,000 members statewide, nearly two months ago started requiring a Phoenix-based company called National Imaging Associates Inc. to provide preapproval of diagnostic imaging exams before coverage for them can be authorized.

These exams include MRI scans, computerized tomography (CT) scans, and some cardiac-related tests. In a story reported by Honolulu Star-Advertiser writer Kristen Consillio, doctors and administrative staffers on the front lines said the result has been delays of up to a few weeks between the time the tests are ordered and the time they often get approval.

HMSA executives emphasized that this general policy has been in place for several years, but added that many of its doctors had received waivers from that requirement, enabling them to order the tests readily. Effective Dec. 1, those waivers were canceled.

Although tests can be ordered without preapproval in emergency situations, they said, the tests aren’t always justified or effective in pinpointing the medical problem and needlessly expose patients to risks and drive up costs.

Since the issue came to light Sunday, HMSA executives have countered by saying that the policy change is temporary. It’s needed now to investigate why Hawaii doctors order these tests at a rate higher than the national average, said Dr. Mark Mugiishi, HMSA’s chief medical officer, adding that the company aims to begin reinstating waivers in a few months.

That reinstatement is a commitment the insurer must fulfill. HMSA must work to minimize the burden of the no-waiver period on many doctors and their administrative staffers — and, above all, the impact on patients.

Mugiishi said that Hawaii has long exceeded national averages on tests ordered. HMSA initiated the waivers in an effort to shield doctors who order tests at a rate closer to national averages, he said, and examine more closely those who didn’t. However, he said, more recent studies show the higher-than-average usage rate persists for Hawaii. That prompted HMSA to take a closer look at records for all doctors to find the reason.

If the patients served by a medical practice were sicker than average, that could explain it, Mugiishi said; otherwise, HMSA wanted to ensure that the physicians are observing national standards of care in ordering their tests.

Without a doubt, controlling such costs is a key objective in keeping health care affordable; if they excessively pad doctor medical bills that the insurer must cover, the costs do get passed on in the form of higher premiums.

However, these controls can have unintended consequences, too. Frustrated doctors might direct patients to emergency rooms for faster — but more expensive — care.

Further, according to a 2013 study published in the Journal of the American Board of Family Medicine, prior authorization requirements add significantly to physicians’ costs for office staff, in the range of $2,161 to $3,430 per full-time equivalent physician.

Dr. Christopher Marsh, a Honolulu internist, said his staff often spends 30 to 60 minutes on the phone, answering questions about a claim. And his staff reports that, although the initial online submission of the claim takes only a few minutes, it’s the back-and-forth supplying information that compounds the delay.

Mugiishi said there was training offered starting last October, before the waivers were canceled, and that each provider is assigned a support person to help them run interference on the claim, should technical or other problems arise.

That should ease any logjam, as long as HMSA ensures it has enough staff assigned to keep the communication channels clear for providers.

The company should return to more targeted oversight of medical practices as quickly as possible. HMSA certainly needs to manage health resources effectively, but its first obligation is to maintain good access to medical services for its members.