AUSTIN, Texas -- A top Texas health official is stepping down after co-authoring a study that drew strong backlash from Republican leaders for suggesting that cuts to Planned Parenthood are restricting access to women's health care statewide.

Rick Allgeyer, director of research at the Texas Health and Human Services Commission, was facing possible discipline for the study published this month in the New England Journal of Medicine. He was eligible for retirement and will leave in March, agency spokesman Bryan Black said Thursday.

Black said that Allgeyer -- who has worked in Texas government for more than 20 years -- broke policy by working on the study on taxpayer time. Other co-authors included one of Allgeyer's subordinates at the health commission, University of Texas researchers and an Austin attorney who represented Planned Parenthood in lawsuits over being excluded from the program the study examined.

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"He should have never been putting in time on this study during the normal business day, he was paid to perform state business," Black said in an email.

Published in one of the nation's most prominent medical journals, the study found that fewer women in Texas have obtained long-acting birth control, such as intrauterine devices, after the GOP-controlled Legislature barred the nation's largest abortion provider from a state women's health program in 2013. Births paid for under Medicaid also increased among some women.

Republicans who were behind Planned Parenthood's ouster rebuked the study and have demanded that Texas Health Commissioner Chris Traylor explain why Allgeyer and another state employee were involved. Black did not address the status of Imelda Flores-Vazquez, a program specialist, who worked under Allgeyer and joined the agency in 2014. Black said neither state employee told superiors they were working on the study, which Black has said was a violation at the 55,000-person agency.

Allgeyer did not immediately return a phone message seeking comment.

Leading the backlash to the study is Republican state Sen. Jane Nelson, a powerful state budget-writer and architect of Texas' current women's health program. She dismissed the findings as biased and invalid, in part because the research was funded by the nonprofit Susan T. Buffet Foundation, which is a major supporter of Planned Parenthood and other abortion rights groups.

Nelson has said the study ignored other state health services for women and says more Texas women filed claims for long-acting contraceptives in 2014 than 2012, when Planned Parenthood was still part of the state program. She wrote a letter to Traylor last week that ordered his agency to review the study and provide an analysis on Medicaid births.

"Critical evaluation is essential to good government, but women should not be misled into thinking the services they need are not available to them," Nelson wrote.

Planned Parenthood officials have said the study showed the impact of "politically motivated" decisions.

Texas barred Planned Parenthood from state planning services the same year that then-Gov. Rick Perry signed tough abortion restrictions that shuttered clinics across the state.

Those restrictions will go before the U.S. Supreme Court next month in a major abortion rights case that could impact similar measures adopted in other GOP-controlled states.