Table 1.

 Shoulder injury rates per 10,000 athlete-exposures (AEs) among collegiate baseball student-athletes by division

	Injuries (n)	AEs (n)	Injury Rate* (per 10,000 AEs)	aIRR* (95% CI)
Total	463	804739 §	4.0
Division I	245	356202	4.9	Referent
Division II	82	177757	3.3	0.67 (0.52, 0.86) 1.49 (1.16, 1.92) †
Division III	136	269745	3.5	0.71 (0.57, 0.88) 1.41 (1.14, 1.74) †
				DII vs DIII‡: 0.94 (0.71, 1.24)

^*Adjusted by year and division;

^†aIRR expressed as inverse ratio for interpretation of injuries in Division I relative to Division II and Division III, as appropriate.

^‡Referent category for specific aIRR

^§Total exposures and yearly exposures are greater than division exposures summary because of undefined division exposures

aIRR = adjusted injury rate ratio