One of the hottest debates in the Thoroughbred industry failed to gain much clarity Monday as a year's worth of analysis from an injury database revealed no major statistically significant difference in the rate of fatalities for horses starting on dirt tracks compared to synthetics.

During a presentation from University of Glasgow epidemiologist Tim Parkin on the opening day of the Welfare and Safety of the Racehorse Summit at Keeneland, results from the Equine Industry Database collected Nov. 1, 2008, to Oct. 31, 2009, showed the rate of fatalities on dirt tracks was 2.14 per 1,000 starts while turf and synthetic tracks had a fatality rate of 1.78.

The study doesn't differentiate among different types of synthetic surfaces, such as Polytrack, Pro Ride, Tapeta and Cushion Track.

The data was collected from 73 tracks; the overall fatality rate was 2.04 per 1,000 starts. Included in the data are horses that suffered fatal injuries during races and immediately after races, and those that succumbed to race-related injuries after race day.

"As the number of starts recorded in the database continues to grow, more complex statistical analyses can focus upon multiple variables studied in concert to better understand the myriad of factors which may contribute to fatal and non-fatal injuries," Parkin said.

Considering the early stages of the data and that dirt racing is still more prevalent throughout North America compared to synthetic tracks, Parkin and Dr. Mary Scollay, the equine medical director for the Kentucky Horse Racing Commission and consultant on the Equine Injury Database, cautioned industry insiders not to draw broad conclusions from the first-year report.

"This tells us the debate goes on," said Scollay, who spearheaded the launch of the Equine Injury Database in July 2008. "Opinions are probably not going to be changed based on the information we've presented.

"This is a first step. The lack of statistical significance doesn't mean there is or is not a difference. We don't have the answer to the $64,000 question, and honestly even if there were statistically significant difference at this point, it is not the same as saying one surface is safer than another. There are lots of things that go into what is or is not a safe practice, and to just focus on the surface ... you're missing the boat."

The dirt-versus-synthetic question might be unresolved, but the study did reveal a significant difference when evaluating the data by gender.

According to the database results, female racehorses are about half as likely to make a start that results in fatal injury than intact, or non-gelded, males.

The rate of fatalities for fillies and mares was 1.79 per 1,000 starts compared to 3.37 for intact males. There was no significant data suggesting females are more at risk for fatal injury when racing against males.

"It's been demonstrated before in a couple different studies but probably not as dramatic as this," Parkin said of the gender-based results. "But I'd be wary about speculating the reasons behind it until we take into account the other variables."

One of the factors that probably contributed to the higher fatality rate of intact males is the influence from the commercial side of the industry.

Whereas well-bred fillies have inherent residual breeding value regardless of whether they make it to the races, there is greater pressure for potential stallions to deliver on the track to earn a career in the shed.

"There is an influence independent of muscular, skele tal factors ... in the horse that has reproductive potential," Scollay said. "The decision-making process may be different for the same injury in a horse that has the opportunity to go to the breeding shed as opposed to a horse that doesn't have that opportunity."

During a panel on safe training practices, Neil Howard, trainer of 2003 Horse of the Year Mineshaft, reiterated the demands on conditioners to at times ask more of their horses when they would rather back off.

"Most people cannot afford to wait the time they need to, and sometimes we rush," Howard said. "They need you to fill a race, and you hate to say no. There are a lot of little things that are pushing us a bit."

While there was no major statistical evidence to suggest weight carried or race distance has an influence on the instances of fatalities, it was found that juvenile horses are 30 percent less likely to suffer fatal injuries than runners 3 or older.

The Equine Injury Database has 86 tracks participating, representing 86 percent of the flat racing days in North America. As part of the tracks' agreement to participate, however, the data from individual tracks is not made public.

During the past few years, a handful of racetracks across the country have made a move toward synthetics. California required that all of its major tracks install synthetic surfaces by the beginning of 2008.

Keeneland, which installed its synthetic Polytrack surface in fall 2006, has publicized its fatality rate of 1.01 per 1,000 starts from Jan. 1, 2007, through June 24, 2010.

"I'm confident that when they get more data, these tracks are safer," Keeneland President Nick Nicholson said of the synthetics. "The data we released today is 31/2 years of data, which is more and it far exceeded the threshold for scientific randomness.

"I would encourage every track to release" its fatality rate, he said. "It's not pleasant, but we've got a responsibility to continue to do better and better."

The Welfare and Safety of the Racehorse Summit ends Tuesday, when the agenda includes a meeting of a panel to make recommendations for implementing practices discussed Monday.