A state law designed to deter the filing of frivolous medical malpractice lawsuits was declared unconstitutional Tuesday by the Oklahoma Supreme Court.

This is the third time the state Supreme Court has struck down similar legislation.

In each case, the Legislature attempted to deter frivolous negligence lawsuits by requiring the person filing the lawsuit to include an affidavit from an expert witness attesting that the claim has merit.

“The obvious purpose of the affidavit requirement reflects the Legislature’s desire to weed out non-meritorious negligence claims,” the Supreme Court noted.

However, all three rejected versions of the state statute created “a costly, meaningless and arbitrary barrier to court access,” the Court said.

Justices also ruled that the rejected statute was an unconstitutional special law that “impinges on the district court’s adjudicative authority.”

Legislatively removing “the discretionary component in (the) adjudicative process is a usurpation of the courts’ freedom that is essential to the judiciary’s independence from the other two branches,” the Supreme Court said.

Wes Glinsmann, executive director of the Oklahoma State Medical Association, expressed disappointment in the ruling Tuesday.

“We are in the process of reviewing the ruling but, at first glance, it certainly appears to be a disappointing step backward,” Glinsmann said. “We believe the certificate of merit has been an important legal reform that helped prevent baseless lawsuits, and we will look carefully at our options and next steps to address today’s ruling.”

The Supreme Court struck down slightly different versions of the law in 2006 and 2013 before rejecting the latest version of the law Tuesday.

The court first rejected the expert affidavit requirement in 2006 in the case of Zeier vs. Zimmer. The Court ruled that was an unconstitutional special law that placed stiffer pleading requirements on medical malpractice lawsuits than other negligence lawsuits. The courts also said the expert witness requirement created an unconstitutional monetary barrier to court access.

The Legislature came back with a modified law that attempted to satisfy the Court’s objections by making the affidavit a requirement of all professional negligence actions and not just medical malpractice claims. In 2013, the Court ruled in Wall vs. Marouk that was also an unconstitutional special law that placed a greater legal and financial burden on victims of professional negligence than victims of general negligence.

The Legislature tried once again to fix the problem — this time by requiring expert affidavits with the filing of all civil negligence actions in which expert testimony is required to establish a departure from applicable standards of care and resulting harm.

Tuesday, the Supreme Court ruled that effort also fell short of meeting constitutional requirements.