NEWS
Fatality statistics inconclusive on racetrack surfaces
Posted: Monday, June 28, 2010 11:50 AM
by Frank Angst
A long-awaited industry study of a year’s worth of catastrophic equine injuries in North American racing determined no statistically significant difference between racing on traditional dirt tracks compared with synthetic surfaces.
While races studied in the first full year of the Equine Injury Database did determine the catastrophic injury rate on synthetic racing surfaces was 16.8% lower than on dirt surfaces, the epidemiologist who studied the numbers, Tim Parkin of the University of Glasgow, said the difference was not statistically significant because of a limited sample size for synthetic starts.
The study determined an injury rate of 1.78 catastrophic injuries per 1,000 starts on synthetic surfaces and 2.14 per 1,000 dirt starts. The study also found a rate of 1.78 on turf starts for an overall catastrophic breakdown rate of 2.03 per 1,000 starts. Races examined were contested from November 1, 2008 through October 2009.
Kentucky Equine Medical Director Mary Scollay-Ward, D.V.M., who helped create the Equine Injury Database, said more study is needed on the two types of surfaces.
“It tells us the debate goes on. Opinions are probably not going to be changed based on the information we’ve presented,” Scollay-Ward said. “Further analysis will give us better, clearer information. Right now, we’re not able to say with certainty. We need more time; we need more data. We do not have the answer to the $64,000 question.”
The study’s numbers were unveiled on the first day of the third Welfare of the Racehorse Summit on Monday at the Keeneland Race Course sales pavilion.
The relatively low number of synthethic races studied in the first year of the Equine Injury Database was the biggest reason Parkin determined the 16.8% difference in catastrophic injury rates was statistically insignificant. Because of the few races studied, the synthetic statistic had a larger possible variation listed between 1.47 per 1,000 starts and 2.16 per 1,000 starts.
Because more dirt starts were available, there was a smaller margin of error. It ranged from 1.97 to 2.32 per 1,000 starts. Parkin expects two more years of study to provide a clearer picture on the issue. A similar difference in breakdown rates at that time probably would be significant because variation would be reduced.
“More data provides us with better certainty of what we’re looking at,” Parkin said. “We’ll have much more certainty on this in two years, three years. … Basically, the more starts you have, the greater the certainty about the numbers you’ll have. The dirt starts are much tighter. With turf and synthetic, we’re less certain. We have to wait for those numbers.”
The surface issue was one of five areas Parkin examined in his statistical analysis. He found statistical evidence that males break down more often than females and that two-year-olds break down less often than older horses. He did not find an increased injury risk for females racing against males or a fluctuation in breakdown rates based on the condition of the various surfaces.
In looking at the gender issue, Parkin found non-gelded males broke down at a rate of 3.37 times per 1,000 starts, nearly twice as often as the female rate of 1.79.
“It’s been demonstrated before in a couple of different studies but probably not as dramatically as that,” Parkin said. “I’d be wary of speculating on the reasons behind it until we take into account all of the variables.”
Scollay-Ward pointed out that owners may be more cautious with their female horses, showing a willingness to retire them to broodmare careers if they suffer minor injuries.
“She’s not going to have the opportunity to sustain a catastrophic injury down the road,” Scollay-Ward said. “There’s an influence beyond any musculoskeletal makeup inherent in the horse.”
Parkin also found two-year-olds to have a relatively low breakdown rate of 1.36 per 1,000 starts, a rate that increased each year to 2.59 for five-year-olds before going back down below 2.0 per 1,000 starts for six-year-olds and older. He concluded that starts made by two-year-olds are less likely to end in fatality than starts by older horses.
Parkin and Scollay-Ward said statistics gathered in a preliminary study before the Equine Injury Database was created were not used because of concerns about differences in how that information was collected, compared with the consistent format now in place. That information found a similar breakdown rate for dirt starts, 2.04 per 1,000 starts, but a lower rate for synthetic surfaces, 1.47, when compared with the current study.
Parkin said it will be easier to assemble the information in future years now that spreadsheets are in place. He said the study will revisit all of the current issues but will move toward more multi-variable models.
The summit also provided updates from the Racing Medication and Testing Consortium, National Thoroughbred Racing Association Safety and Integrity Alliance, and Thoroughbred Safety Committee. In the afternoon, industry leaders participated on panels discussing racing equipment and safety, training practices, and transitioning Thoroughbreds to post-racing careers.
The summit continues on Tuesday with private panel meetings in the morning before a public presentation at 11 a.m. EDT on implementation of some of the ideas that were discussed on Monday. The summit is presented by Grayson-Jockey Club Research Foundation and The Jockey Club.
Frank Angst is senior writer for Thoroughbred Times
