Researchers looked at the 250 drugs with the greatest Medicare Part D spending in 2016, and found 46 percent of them did not have a cost-effectiveness analysis. Those 115 drugs with absent cost-effectiveness analyses represent 33 percent of all Medicare Part D spending.
For the 135 drugs with available cost-effectiveness analyses, many of the studies failed to meet minimum quality standards, according to the report.
Ninety-one of the drugs included in the study had a generic equivalent, and 159 had some exclusivity.
