In the United States, "Opt-Out" States Show No Increase in Access to Anesthesia Services for Medicare Beneficiaries Compared with Non-"Opt-Out" States.

In the United States, anesthesia care can be provided by anesthesiologists or nurse anesthetists. Since 2001, 17 states have exercised their right to "opt-out" of the federal requirement that a physician supervise the administration of anesthesia by a nurse anesthetist, with the majority citing increased access to anesthesia care as the rationale for their decision. By using Medicare data, we found that most (4 of 5) cohorts of "opt-out" states likely experienced smaller growth in anesthesia utilization rates compared with non-"opt-out" states, suggesting that opt-out was not associated with an increase in access to anesthesia care.