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. Author manuscript; available in PMC: 2020 Nov 1.
Published in final edited form as: Am J Sports Med. 2019 Oct 7;47(13):3173–3180. doi: 10.1177/0363546519876925

Table 2:

The Relationship of Risk Factors to the Classification of and Relationship to Follow-up in the Study Cohort

Risk Factors Study Cohort
N = 3,202 Completed
Follow-up
Lost to Follow-up p-value
2,821 (88%) 381 (12%)
Consortium Site 0.0029
#1 684 (21%) 610 (22%) 74 (19%)
#2 185 (6%) 165 (6%) 20 (5%)
#3 869 (27%) 737 (26%) 132 (35%)
#4 130 (4%) 124 (4%) 6 (2%)
#5 139 (4%) 122 (4%) 17 (4%)
#6 757 (24%) 682 (24%) 75 (20%)
#7 438 (14%) 381 (14%) 57 (15%)
Sex
Male 1,791 (56%) 1,539 (55%) 252 (66%) <0.0001
Female 1,411 (44%) 1,282 (45%) 129 (34%)
Race
White 2,645 (83%) 2,394 (85%) 251 (66%) <0.0001
Black 278 (9%) 194 (7%) 84 (22%)
Other 279 (9%) 233 (8%) 46 (12%)
Marital Status
Married 882 (29%) 803 (30%) 79 (22%) 0.0041
Single 2,090 (68%) 1,827 (67%) 263 (73%)
Separated 112 (4%) 93 (3%) 19 (5%)
Missing 118 (4%)
Smoking Status
Current 292 (9%) 236 (9%) 56 (15%) 0.0002
Never 2,548 (80%) 2,264 (81%) 284 (76%)
Quit 325 (10%) 292 (10%) 33 (9%)
Missing 37 (1%)
Home Phone Number Provided
Yes 2,984 (93%) 2,635 (93%) 349 (92%) 0.1891
No 218 (7%) 186 (7%) 32 (8%)
Cell Phone Number Provided
Yes 1,136 (36%) 998 (81%) 138 (78%) 0.257
No 265 (8%) 226 (19%) 39 (22%)
Missing 1,801 (56%)
Primary Email Provided
Yes 2,070 (65%) 1,859 (66%) 211 (55%) 0.0001
No 1,132 (35%) 962 (34%) 170 (45%)
Secondary Email Provided
Yes 273 (9%) 251 (9%) 22 (6%) 0.0405
No 2,929 (91%) 2,570 (91%) 359 (94%)
Years of School Completed 14 (11, 16) 14 (11, 16) 13 (11, 16) 0.0013
Missing 17 (1%)
Average Hours Worked per Week 25 (0, 44) 25 (0, 45) 30 (0, 40) 0.9272
Missing 564 (18%)
Works Full Time
Yes 1,181 (37%) 1,050 (37%) 131 (34%) 0.2812
No 2,021 (63%) 1,771 (63%) 250 (66%)
Works Part Time
Yes 314 (10%) 278 (10%) 36 (9%) 0.8026
No 2,888 (90%) 2,543 (90%) 345 (91%)
Works as Homemaker
Yes 99 (3%) 88 (3%) 11 (3%) 0.8058
No 3,103 (97%) 2,733 (97%) 370 (97%)
Retired
Yes 24 (1%) 23 (1%) 1 (0%) 0.3499
No 3,178 (99%) 2,798 (99%) 380 (100%)
Student
Yes 1,504 (47%) 1,335 (47%) 169 (44%) 0.2761
No 1,698 (53%) 1,486 (53%) 212 (56%)
Disabled
Yes 100 (3%) 79 (3%) 21 (5%) 0.0043
No 3,102 (97%) 2,742 (97%) 360 (95%)
Working Other
Yes 131 (4%) 102 (4%) 29 (8%) 0.0002
No 3,071 (96%) 2,719 (96%) 352 (92%)
How many people live at home with patients 2 (1, 3) 2 (1, 3) 2 (1, 3) 0.4558
Missing 330 (10%)
Lives Alone
Yes 292 (9%) 259 (9%) 33 (9%) 0.7408
No 2,910 (91%) 2,562 (91%) 348 (91%)
Lives with Parents
Yes 1,301 (41%) 1,153 (41%) 148 (39%) 0.4496
No 1,901 (59%) 1,668 (59%) 233 (61%)
Lives with Partner
Yes 1,012 (32%) 909 (32%) 103 (27%) 0.0409
No 2,190 (68%) 1,912 (68%) 278 (73%)
Lives with Children
Yes 717 (22%) 635 (23%) 82 (22%) 0.6643
No 2,485 (78%) 2,186 (77%) 299 (78%)
Lives with Other
Yes 930 (29%) 818 (29%) 112 (29%) 0.8719
No 2,272 (71%) 2,003 (71%) 269 (71%)
Lives with Siblings
Yes 332 (24%) 297 (24%) 35 (20%) 0.1891
No 1,069 (76%) 927 (76%) 142 (80%)
Not Applicable 1801 1597 204
Pre-OP KOOS Symptom Score 68 (54, 82) 68 (54, 82) 64 (50, 79) 0.0004
Missing 5 (0%)
Pre-OP KOOS Pain Score 75 (61, 86) 75 (61, 86) 69 (53, 83) <0.0001
Missing 7 (0%)
Pre-OP KOOS ADL Score 87 (71, 96) 87 (71, 96) 82 (63, 93) <0.0001
Missing 3 (0%)
Pre-OP KOOS Sports and Rec Score 50 (25, 75) 50 (25, 75) 45 (20, 70) 0.0234
Missing 63 (2%)
Pre-OP KOOS QOL Score 38 (19, 50) 38 (19, 50) 31 (19, 44) 0.0006
Missing 8 (0%)
Pre-OP MARX Score 12 (8, 16) 12 (8, 16) 12 (6, 16) 0.3665
Missing 26 (1%)
Pre-OP IKDC Score 51 (39, 62) 51 (39, 63) 46 (33, 59) <0.0001
Missing 47 (1%)