FAIR PLAY AS AN INJURY PREVENTION INTERVENTION: DO YELLOW CARD ACCUMULATION POLICIES REDUCE HIGH SCHOOL SOCCER INJURIES?

Background:

Pediatric sports-related injuries are common, yet prevention efforts too often go unevaluated. Collins et al. studied nine U.S. high school (HS) sports during 2005/06-2006/07, finding boys’ and girls’ soccer had the highest injury rates related to illegal activity. Several states have implemented yellow card accumulation policies (YCPs) in an effort to prevent injuries.

Hypothesis/Purpose:

Purpose: Evaluate the effectiveness of YCPs in reducing HS soccer competition injuries by comparing injury rates and patterns in states with and without YCPs. Hypotheses:

Athlete-athlete contact injury rates are lower in states with YCPs

Methods:

Retrospective cohort study of NHFS member state association HS soccer players injured during competition in 2005/06-2017/18. Athlete exposure (AEs) and injury data collected from a national sports injury surveillance system, High School RIO. Poisson regression assessed the effects of YCPs on injury rates and patterns.

Results:

Of 50 NFHS member states associations, high schools from 47 were represented. Overall, 901 athlete-athlete contact injuries occurred during 352,775 competition AEs in states with YCPs and 3,525 during 1,459,708 AEs in states without YCPs. There was no significant difference in overall contact injury rates (rate ratio [RR] 1.06; 95% confidence interval [CI]: 0.98-1.14) between schools in states with and without YCPs. A small, significant increase in overall contact injury rates was discernable after states’ adoption of YCPs (RR 1.17; 95% CI: 1.03, 1.34), particularly in boys’ soccer (RR 1.32; 95% CI 1.08-1.62). A significantly lower proportion of injuries resulting in > 3 weeks’ time loss occurred in states with YCPs (injury proportion ratio [IPR] 0.81; p=0.047), while other severe injuries did not differ. There were no significant differences in YCPs’ effect by gender (p=0.319).

Conclusion:

Among HS boys’ and girls’ soccer players, playing in states with YCPs did not lower athlete-athlete contact injury rates, although injuries resulting in > 3 weeks’ time loss were less prevalent in states with YCPs. Athlete-athlete contact injury rates were slightly higher in states following adoption of YCPs, particularly in boys’ soccer. Enactment of YCPs alone, without proper enforcement, may not be a sufficient injury prevention strategy. Further studies assessing the impact of HS soccer YCPs need to consider the effects of state level YCP enforcement, documented illegal activity/foul play, and Fair Play education.

Tables/Figures:

Table 1.

Rate of Athlete-Athlete Contact Injuries Sustained During Soccer Competition in High Schools in States with and without Yellow Card Policies, National High School Sports-Related Injury Surveillance Study, USA, 2005/06-2017/18

	# Injuries	# Competition AEs	Rate per 10,000 AE	RR (95% CI) a
Overall
With YCP	901	352775	25.5	1.06 (0.98, 1.14)
Without YCP	3525	1459708	24.1	Ref
Boys’ Soccer
With YCP	430	188626	22.8	1.10 (0.99, 1.22)
Without YCP	1625	783851	20.7	Ref
Girls’ Soccer
With YCP	471	164149	28.7	1.02 (0.92, 1.13)
Without YCP	1900	675857	28.1	Ref

^aRate Ratio (RR) is the ratio of total injury rate in YCP schools to total injury rate in No YCP schools.

Table 2.

Rate of Athlete-Athlete Contact Injuries Sustained During Soccer Competition in High Schools in states with Yellow Card Policies Pre- and Post- Policy Enactment, National High School Sports-Related Injury Surveillance Study, USA, 2005/06-2017/18

	# Injuries	# Competition AEs	Rate per 10,000 AE	RR (95% CI) a
Overall
Post-YCP	901	352775	25.5	1.17 (1.03, 1.34)
Pre-YCP	285	130686	21.8	Ref
Boys’ Soccer
Post-YCP	430	188626	22.8	1.32 (1.08, 1.62)
Pre-YCP	118	68262	17.3	Ref
Girls’ Soccer
Post-YCP	471	164149	28.7	1.07 (0.90, 1.28)
Pre-YCP	167	62424	26.8	Ref

^aRate Ratio (RR) is the ratio of total injury rate in Post YCP enactment to total injury rate in Pre YCP enactment.

Table 3.

Severe Athlete-Athlete Contact Injuries Sustained During Soccer Competition in High Schools in states with and without Yellow Card Policies, National High School Sports-Related Injury Surveillance Study, USA, 2005/06-2017/18

Injury	YCP# (%)b	No YCP# (%)	IPR (95% CI)a
Concussion	247 (27.4)	945 (26.8)	1.03 (0.88,1.22)
Fracture	72 (8.0)	321 (9.1)	0.87 (0.66,1.13)
ACL	34 (3.8)	120 (3.4)	1.11 (0.76,1.64)
Injury required surgical intervention	51 (5.7)	199 (5.7)	1.00 (0.73,1.38)
Injury resulting in >3 weeks’ time lossc	124 (13.8)	581 (16.5)	0.81 (0.66, 1.00)d

^aInjury Proportion Ratios (IPRs). For all IPRs, No YCP is the referent category.

^bFor each category of injury above, % indicates what proportion of all athlete-athlete contact injuries sustained during soccer competition were accounted for by the specific injury category.

^cInjury resulting in >3 weeks’ time loss includes the following categories: “Returned to activity in 22 days or more,” “medical disqualification for season,” or “medical disqualification for career.”

^dAn upper limit of 95% CI equals 0.997, which is less than 1.00.