A substantial proportion of Medicare beneficiaries, between 25 and 42 percent, are affected by the utilization of low-value services, including low-value imaging and cancer screening, according to a study published online May 12 in JAMA Internal Medicine.

While the study sheds some light on the utilization of low-value services, senior author J. Michael McWilliams, MD, PhD, of Harvard Medical School in Boston, and colleagues said the work also underscores the limitations of a direct approach to measuring wasteful care.

“Despite their imperfections, claims-based measures of low-value care could be useful for tracking overuse and evaluating programs to reduce it. However, many direct claims-based measures of overuse may be insufficiently accurate to support targeted coverage or payment policies that have a meaningful effect on use without resulting in unintended consequences,” they wrote.

McWilliams and colleagues consulted evidence-based lists of services that provide minimal clinical benefit, such as the American Board of Internal Medicine Foundation’s Choosing Wisely program, as well broader medical literature to create a list of 26 measures of low-value services. Included in the imaging category were:

• Imaging for nonspecific low back pain;
• Preoperative radiography;
• Head imaging for headache;
• Head imaging for syncope; and
• CT for rhinosinusitis.

The authors created claims-based measures of these services, and used 2009 claims for more than 1.3 million Medicare beneficiaries to assess the proportion of beneficiaries receiving these services as well as the associated spending.

The authors noted the challenge in trying to track the use of low-value services stems from the fact that the value of services depends on the specific clinical situation, and administrative claims data generally lack the clinical detail necessary to distinguish appropriate from inappropriate use.

As such, McWilliams and colleagues used estimates that ranged from being more sensitive to those that traded off sensitivity for specificity. More sensitive measures found that low-value services affected 42 percent of beneficiaries and constituted 2.7 percent ($8.5 billion) of overall annual spending, while specific versions of the measures found 25 percent of beneficiaries were affected and constituted 0.6 percent ($1.9 billion) of overall spending.

“For example, our more sensitive measure of low-value imaging for low back pain captured more inappropriate use of imaging studies at the expense of including some appropriate use. Our more specific measure was less likely to include appropriate use but probably excluded many low-value studies, as suggested by the 3-fold reduction in the number of studies captured,” wrote the authors.

One of the larger gaps between measures was seen in colon cancer screening for older elderly patients, which according to the more sensitive measure accounted for $573 million compared with $7 million for the more specific measure.

McWilliams and colleagues also found that, while spending on low-value services varied across regions, spending on such services was substantial. This occurred even in regions where it was lowest, suggesting direct measurements are superior to relative spending comparisons for detecting overuse as it may be substantial even for relatively efficient providers.

Bundled payment models and other broader payment reforms, as opposed to rigid rules derived from incomplete clinical data, could result in greater provider discretion in targeting low-value services while still discouraging their use, concluded the authors.