The study, which focused on anti-hypertensive drugs, found that benefit-plan members subject to step therapy incurred $99 more in quarterly health care expenditures than a comparable group. Moreover, plan members in step therapy programs also had more inpatient admissions and emergency room visits, the study found.
"When step therapy is implemented, there is an associated increase in inpatient and ER visits and a reduction in prescription drug use," said Tami L. Mark, lead author of the study and director of analytic strategies at Thomson Reuters Healthcare in Washington.
She suggested this might be caused by patients not filling their prescriptions.
"You go to a doctor and the doctor prescribes a drug—not knowing that it has to be a generic—and you find out it's not covered or more expensive than you had expected, so you don't fill the prescription," Mark said.
To prevent this unintended consequence from occurring, she advised employers to make sure doctors know about step therapy requirements.
"I think you have to evaluate how it's actually being implemented and what the overall impact is. Maybe the way it's being implemented is not as intended and needs to be reconsidered," she said.
The study compared the health care costs of 11,851 employees and dependents at two companies with benefit plans that required step therapy with 30,882 employees and dependents of two companies that did not.
Data for 2003 through 2006 came from MarketScan Research Databases kept by Thomson Reuters.
The study, "The Effects of Antihypertensive Step Therapy Protocols on Pharmaceutical and Medical Utilization and Expenditures," was published in the February issue of the American Journal of Managed Care.