HARRISBURG — The number of medical malpractice lawsuits filed against doctors and hospitals in Pennsylvania dropped last year for the sixth year in a row.

A total of 1,491 malpractice lawsuits were filed in 2010, according to a report released last week by the Administrative Office of Pennsylvania Courts. Court officials reported that 163 cases reached a jury, and 133 verdicts — 81 percent — favored the defense.

Chief Justice Ronald Castille said there’s been a 45 percent decline in cases since the early part of the decade, when the state made legal changes intended to weed out frivolous cases.

Among the rules that took effect in 2002 — when malpractice lawsuits peaked at 2,904 — is a requirement that plaintiffs get another doctor in the same field to sign off on the claims. Another requires malpractice claims to be filed in the county where the alleged malpractice occurred, preventing lawyers from “forum shopping” or filing cases in counties where they believe juries will be more sympathetic.

Attorneys also attributed the drop statewide to an increase in litigants using private mediators.

“Over the past 10 years, private mediation has definitely increased,” said attorney Bryan Neft, an officer in the civil litigation section of the Allegheny County Bar Association.

Pittsburgh attorney George Kontos, said malpractice lawsuits are “not as prolific as people think,” and he probably rejects about 90 percent of the people seeking one.

“There’s not a medical malpractice crisis in this state. There hasn’t been for many years,” Kontos said. “A plaintiff’s attorney can’t afford to take a frivolous lawsuit.”