Table 1.

Risks of sociodemographic characteristics for PARI

Characteristics	All (N=4758), n (%)	Non-PARI (N=3677), n (%)	PARI (N=1081), n (%)	Adjusted OR	95% CI
City
Jinan	1267 (26.6)	1111 (87.7)	156 (12.3)	1 (ref.)
Shantou	2123 (44.6)	1403 (66.1)	720 (33.9)	3.932***	3.230 to 4.786
Hong Kong	1368 (28.8)	1163 (85.0)	205 (15.0)	1.084	0.841 to 1.396
Study year
Year 1	1496 (31.4)	1125 (75.2)	371 (24.8)	1.397**	1.109 to 1.760
Year 2	1462 (30.7)	1121 (76.7)	341 (23.3)	1.153	0.948 to 1.401
Year 3	1800 (37.8)	1431 (79.5)	369 (20.5)	1 (ref.)
Gender
Male	1343 (28.2)	976 (72.7)	367 (27.3)	1.404***	1.202 to 1.640
Female	3415 (71.8)	2701 (79.1)	714 (20.9)	1 (ref.)
Residence type
Dormitory	2908 (61.1)	2210 (76.0)	698 (24.0)	1 (ref.)
Home	1742 (36.6)	1377 (79.0)	365 (21.0)	1.016	0.861 to 1.198
Others	108 (2.3)	90 (83.3)	18 (16.7)	0.820	0.469 to 1.434
University sports team member
No	4262 (89.6)	3380 (79.3)	882 (20.7)	1 (ref.)
Yes	496 (10.4)	297 (59.9)	199 (40.1)	3.136***	2.528 to 3.889
Other sports team member
No	4472 (94.0)	3512 (78.5)	960 (21.5)	1 (ref.)
Yes	286 (6.0)	165 (57.7)	121 (42.3)	2.182***	1.678 to 2.838
Any chronic disease/symptom
No	4583 (96.3)	3563 (77.7)	1020 (22.3)	1 (ref.)
Yes	175 (3.7)	114 (65.1)	61 (34.9)	1.561*	1.111 to 2.195
Age (mean±SD, years)	20.00±1.382	20.01±1.426	19.98±1.386	0.983	0.934 to 1.146

Adjusted ORs and 95% CIs of significant variables were calculated after controlling for each other, including city, study year, gender, university/other sports team member and any chronic disease/symptom. Adjusted ORs and 95% CIs of insignificant variables (age and residence type) were obtained after controlling for the significant variables.

*P<0.05, **P<0.01, ***P<0.001.

PARI, physical activity-related injury.