Private Indiana schools that accepted students from low- to middle-income families using state-funded vouchers last year experienced a drop in their passing rates on the state's ISTEP test this year, a newspaper's analysis of test scores shows.

The Journal Gazette of Fort Wayne analyzed the test scores of 189 private schools with voucher students that administered the statewide test and used 2011 data for comparison. The newspaper reported Monday that its analysis showed those schools' passing rates for both math and English fell to 85 percent this year, down from 86 percent the year before.

At the same time, the state's public schools' scores rose slightly, with about 71 percent of students passing both the English and math portions of the test this year, up from about 70 percent last year. Those scores mark an 8-percent gain since the 2008-09 school year.

In 2011, Indiana lawmakers approved the nation's broadest voucher program for low-to-moderate income families. The program, which nearly 4,000 students took advantage of in the 2011-12 school year, allows parents to send their children to private schools using state funding.

School Choice Indiana executive director Lindsey Brown said the group, which supports the voucher law, "fully expected" that some private schools taking on new students would see slight drops in their scores.

"When a school takes on a large number of new students, that's certainly going to impact its scores," she said.

Brown said other choice programs nationwide have shown an initial negative impact before test results grow again.

The Indiana Department of Education has not yet run an aggregate calculation showing how many voucher students passed the test.

But Brown said voucher schools overall performed better than public schools. Specifically, she said 38 percent of voucher schools — or 86 schools — reached the 90-percent pass rate in both subjects, which the state Department of Education set as a goal for every school.

Still, some drops in passing rates at individual private schools were quite large.

For instance, the Ambassador Christian Academy in Gary accepted 110 voucher students at the beginning of the school year. In 2011, 78 percent of the academy's students passed both the math and English portions of the test. That rate dropped to 57 percent this year.

At Blackhawk Christian Jr.-Sr. High in Fort Wayne, 91 percent of students pass the math and English portions last year compared with 83 percent this year. The school's lead administrator, Bill Hartman, said he wasn't shocked at all to see an overall statewide reduction for voucher schools.

"I think there is no question as you broaden the student population your test scores are not going to be as high," he said. "The more you pull the public into the private we will see that."

But he cautioned against blaming the influx of voucher students, saying the majority of Blackhawk's voucher students were in elementary grades.