SPRINGFIELD, Ill. (AP) — A federal judge has refused to grant class-action status to a lawsuit alleging wage discrimination against female doctors at Southern Illinois University School of Medicine.

The State Journal-Register in Springfield reports the case, initiated by former SIU surgeon Dr. Sajida Ahad and joined by four other female doctors, will proceed after the ruling by U.S. District Judge Sue Myerscough.

Myerscough said Ahad failed to show there was a “common cause” to produce a “common answer to the questions of whether and why compensation for female physicians was lower than compensation for similarly situated male physicians.”

The lawsuit alleges female physicians at SIU were being paid more than $12,200 per year less than male doctors for similar work.

SIU officials, who have denied Ahad’s allegations in the past, declined to comment on Myerscough’s Sept. 12 ruling.

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