A new study, published in May in JAMA Internal Medicine, found that Medicare spent $1.9 billion in 2009 for patients to get 26 tests and procedures—including several laboratory tests—that research has shown are not effective. It is the first large-scale research of its type to look into Medicare’s wasteful spending.

The researchers developed a list of 26 “low-value” services, drawing from existing evidence. They examined claims for 1,360,908 Medicare beneficiaries from 2009, looking into the proportion of beneficiaries who received those services, as well as mean per-beneficiary service use and the proportion of total spending on those services. “We compared the amount of use and spending detected by versions of these measures with different sensitivity and specificity. We also estimated correlations between use of different services within geographic areas, adjusting for beneficiaries’ sociodemographic and clinical characteristics,” the authors wrote.

The researchers grouped services into six categories: low-value cancer screening, low-value diagnostic and preventive testing, low-value preoperative testing, low-value imaging, low-value cardiovascular testing and procedures, and other low-value surgical procedures. This included several laboratory tests, such as parathyroid testing in early cardiovascular disease, prostate-specific antigen screening for men older than age 75, cervical cancer screening for women older than age 65, and hypercoagulability testing after deep vein thrombosis.

Based on their research, the authors concluded that “services detected by a limited number of measures of low-value care constituted modest proportions of overall spending but affected substantial proportions of beneficiaries and may be reflective of overuse more broadly. Performance of claims-based measures in supporting targeted payment or coverage policies to reduce overuse may depend heavily on how the measures are defined.”

“We were surprised that these wasteful services were so prevalent,” lead author Aaron Schwartz, an MD/PhD student in the Harvard Medical School Department of Health Care Policy, said in a statement. “Even just looking at a fraction of wasteful services and using our narrowest definitions of waste, we found that one quarter of Medicare beneficiaries undergo procedures or tests that don’t tend to help them get better.”

Read the study online.