The objective of this study was to investigate the relationship between intensive racing and training schedules and risk of either @entity85 ( @entity85 ) or lay-up from racing in California Thoroughbreds. Thoroughbred racehorses that sustained a @entity85 during racing or training and either were subsequently euthanized or died on a California racetrack during 1991 and 1992 were studied using a case-crossover study design. Each study subject (case) provided its own self-matched control information in the form of 'typical' exposure frequency, determined or estimated from historic information. Periods of rapid average daily accumulation of high-speed exercise distance were identified for each @entity1641 from official race and training histories with a sliding 60-day window. Those window frames containing an average daily rate of distance accumulation exceeding 75th percentile cutoff values were classified as exposed frames followed by 30 days of increased risk, or hazard periods. All remaining days (excluding periods of layoff from racing) were considered non-hazard time at risk. The relative risk (RR) of @entity85 within 30 days following a period of rapid accumulation of high-speed exercise distance (during a hazard period) was 4.2 (95% confidence interval [CI] = 3.0, 5.8). Of these 214 cases, 84 (39%) were injured during a hazard period whereas on average only 22% of total career time at risk was hazard time for these @entity1641 . A second analysis was performed for @entity1641 with at least 1 lay-up period from racing of > or = 60 days. RR for a lay-up beginning during a hazard period was estimated for the last lay-up experienced by each @entity1641 . The RR for lay-up beginning during a hazard period was 4.8 (95% CI = 2.9, 8.1). Of these 98 cases, 32 (33%) of the lay-ups began during a hazard period whereas on average, only 22% of at-risk time up to last lay-up was hazard time for these @entity1641 .

A case-crossover study of intensive racing and training schedules and risk of XXXX and lay-up in California thoroughbred racehorses.

@entity85 :: ('MESH:D009140', 'Disease') :: ['catastrophic musculoskeletal injury', 'CMI'] @entity1641 :: ('9796', 'Species') :: ['horses', 'horse']
@entity85 :: (MESH:D009140,Disease) :: ['catastrophic musculoskeletal injury']
