Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois.
Sports Health. 2009 May;1(3):231-5. doi: 10.1177/1941738109334274.
There have been no large-scale epidemiologic studies designed to determine the risk factors related to medical withdrawal in United States Tennis Association junior national tennis tournaments.
Risk of medical withdrawal will increase on the basis of cumulative match volume within a tournament.
A retrospective, cross-sectional analysis was performed of data collected for every match of all 4 United States Tennis Association supernational tournaments (spring, summer, fall, winter) for the boys and girls divisions and for all age divisions (12, 14, 16, 18) during a single year (2005). Logistic regression analysis was performed to determine relative risk of all risk factors. Additional analysis was performed to determine the threshold (ie, match number) at which a player would substantially increase his or her risk of medical withdrawal.
A total of 28336 match exposures were analyzed, with an even distribution with respect to sex and age. The total medical withdrawal rate was 15.6 per 1000 match exposures. Every factor of interest was highly significant in predicting a higher rate of medical withdrawal per 1000 match exposures. The medical withdrawal rate was significantly higher in the fifth match or greater (26.3/1000) versus the first 4 matches (12.7/1000; P < .0001), even when analyzing main draw and singles matches.
In United States Tennis Association national junior tennis tournaments, there is a significant increase in risk of medical withdrawals directly related to older age divisions, boys, singles matches, and main draw matches. Specifically, there is a significant increase in medical withdrawal rate beyond the fourth match in the tournament regardless of whether it is a main draw, consolation, or singles match.
Recommendations can be made to exercise caution in tournaments that involve boys, older age divisions, and singles. In addition, there may be sufficient evidence to suggest intervention within a tournament when players play beyond their fourth match.
目前尚无大规模的流行病学研究旨在确定与美国网球协会青少年全国网球锦标赛中医疗退出相关的风险因素。
在锦标赛中，基于累积比赛量，医疗退出的风险将会增加。
对 2005 年一年中所有男女组别和所有年龄组（12、14、16、18 岁）的四个美国网球协会超级国家锦标赛（春季、夏季、秋季、冬季）的每场比赛的数据进行回顾性、横断面分析。使用逻辑回归分析确定所有风险因素的相对风险。进行了额外的分析以确定运动员将大大增加其医疗退出风险的比赛次数（即比赛次数）。
共分析了 28336 次比赛暴露，在性别和年龄方面分布均匀。总的医疗退出率为每 1000 次比赛暴露 15.6 次。每一个感兴趣的因素都高度显著地预测了每 1000 次比赛暴露的医疗退出率更高。第五次或更多次比赛（26.3/1000）的医疗退出率明显高于前 4 次比赛（12.7/1000；P<.0001），即使在分析主赛和单打比赛时也是如此。
在美国网球协会青少年全国网球锦标赛中，与年龄较大、男孩、单打比赛和主赛比赛直接相关的医疗退出风险显著增加。具体来说，无论是否为主赛、安慰赛或单打赛，在锦标赛中参加第四场比赛后，医疗退出率会显著增加。
可以建议在涉及男孩、较大年龄组和单打比赛的锦标赛中谨慎行事。此外，当运动员参加第四场比赛后，可能有足够的证据表明在锦标赛中进行干预。
