The Need for Overlapping Interventions: Just One Won't Do It

Looking through the MRI

In a prior posting, the Disease Management Care Blog was reminded that the U.S. health care system  is exceptionally complex and non-linear. Thanks to its many overlapping, contradictory, shifting and often non-medical inputs, it defies the simple logic of a single-cause-leading-to-a-single-effect. If economics is the dismal science, health care economics is its dubious spawn.

However, that doesn't mean that multiple coordinated inputs combined with some good luck won't push the health care weather vane in the right direction. For the latest example of this fundamental truism, check out David Lee and Frank Levy's Health Affairs article The Sharp Slowdown In Growth Of Medical Imaging: An Early Analysis Suggests Combination Of Policies Was The Cause.

By way of background, medical imaging has been a high profile issue for policy makers and a headache for insurers because, until recently, the rate of costly "high dollar" imaging studies has been growing much faster than other medical costs.  It has been blamed as one technology-laden driver of health care inflation.  In the meantime, physicians have pointed to a variety of causes (and, by the way, left others unmentioned).  

In this study, the authors examined 10 years' worth of insurance claims for advanced imaging MRI and CAT scans from two multi-state commercial insurance plans and another smaller single state plan.  These data were then pooled with a 5% national random sample of imaging claims from Medicare beneficiaries.  The authors also interviewed radiologists, health administrators, radiology benefit managers and physician recruiters.

The results?  From 2000 through 2005, CT scans grew at a whopping rate of 14.3% but then slowed to 1.4%. MRI slowed in the same periods from 14% to 2.6%. At the same time, starting salaries for radiology specialist physicians significantly declined.
 
What happened?  According to the authors:

1. An industry sprung up.  In another example of the adage that "need is the mother of invention," companies that prior authorize imaging studies for medical necessity (for example) were hired by many commercial insurers.  They had an impact.

2. Skin in the game. Deductibles, co-insurance and co-pays made consumers think twice about agreeing to a study that was going to result in some out-of-pocket spending.

3. Unilaterally imposed fee reductions. Medicare cut the amount it paid for CAT and MRI studies performed in freestanding centers and physicians' offices. Hospitals were left untouched.

4. Glow in the dark.  Media reports on the amount of radiation prompted patients to worry about the long term impact of all those x-rays.

In other words, there was no single lever. Instead, the reduction of high utilization of pricey imaging was due to the confluence of at least four mutually reinforcing trends.

As further evidence of the overlapping trends that extended beyond simple cause-and-effect, Medicare never relied on prior authorization, didn't alter the out of pocket testing expenses for beneficiaries and left the payments for hospital-based imaging untouched. Yet Medicare saw an across-the-board reduction. MRIs don't involve ionizing radiation (they use relatively harmless magnets), but their overall rate went down in concert with CAT scans..

This has important implications for other laudable policy targets.  Based on this experience, waiving out of pocket costs alone are unlikely to increase the use of preventive health care services. Simply paying for the medical home may not make that big a difference.  Quoting the DMCB may not be enough to convince your skeptical friends.  So on and so on.

The obvious implication for the population health management service companies is that if they're going to have a significant impact, the likelihood of a successful outcome is far greater if it is implemented concurrently with other supportive interventions.