Table 1

Participant characteristics at baseline, 3 and 12 months (split by responders (participated in follow-up) and non-responders)

AustraliaThe NetherlandsTotal
Variables*Responders (n=20)Non-responders (n=159)p ValueResponders (n=40)Non-responders (n=91)p ValueResponders (n=60)Non-responders (n=250)
Age (years)28.5 (5.63)28.5 (6.75)0.48525.1 (8.56)23.6 (8.08)0.35226.2 (8.10)27.3 (7.18)
Gender (female) (%)15 (75.0%)85 (54.0%)0.09430 (75.0%)54 (59.3%)0.08545 (75.0%)139 (55.6%)
BMI (kg/m2)24.3 (4.42)24.8 (5.22)0.66822.4 (3.51)23.3 (3.78)0.67323.0 (3.91)24.3 (4.78)
Sport participant (%)14 (70.0%)104 (65.4%)0.80534 (85.0%)68 (74.7%)0.19248 (80.0%)172 (68.8%)
Work status0.4820.601
 Not employed5 (25.0%)23 (14.5%)17 (42.5%)35 (38.5%)22 (33.7%)58 (23.2%)
 Sedentary10 (50.0%)90 (56.6%)10 (25.0%)18 (19.8%)20 (33.3%)108 (43.2%)
 Active5 (25.0%)45 (28.3%)12 (30.0%)35 (26.1%)17 (28.3%)80 (32.0%)
 Unknown01 (0.63%)1 (2.50%)3 (2.29%)1 (1.67%)4 (1.60%)
Duration of knee pain (%) (months)0.5640.713
 1–208 (5.03%)18 (45.0%)32 (35.2%)18 (30.0%)40 (16.3%)
 2–61 (5.0%)16 (10.1%)10 (25.0%)29 (31.9%)11 (18.3%)45 (18.3%)
 6–123 (15.0%)27 (17.0%)6 (15.0%)13 (14.3%)9 (15.0%)40 (16.3%)
 >1216 (80.0%)104 (65.4%)6 (15.0%)17 (18.7%)22 (36.7%)121 (49.2%)
 Unknown04 (2.52%)00
Bilateral pain (%)13 (65.0%)89 (56.0%)0.48323 (57.5%)56 (61.5%)0.66336 (60.0%)145 (58.0%)
Allocated preferred treatment0.5920.253
 Not allocated7 (35%)59 (37.1%)13 (32.5%)39 (42.8%)20 (33.3%)98 (39.2%)
 Allocated8 (40.0%)47 (29.6%)15 (37.5%)35 (38.5%)23 (38.3%)82 (32.8%)
 No treatment preference3 (15.0%)35 (22.0%)12 (30.0%)16 (17.6%)15 (25.0%)51 (20.4%)
 Unknown2 (10.0%)18 (11.3%)01 (1.1%)2 (3.33%)19 (7.60%)
Recruitment (health professional) (%)02 (1.26%)1.00040 (100%)91 (100%)NA20 (33.3%)154 (62.3%)
Global recovery (% recovered) (months)
 310 (50.0%)560.46814 (35.0%)33 (40.2%)0.57624 (40.0%)89 (39.9%)
 129 (45.0%)870.34123 (59.0%)43 (55.1%)0.69232 (54.2%)130 (56.8%)
Usual or resting pain (VAS/100)
 Baseline36.1 (17.1)36.4 (16.6)0.95239.8 (22.0)41.3 (23.2)0.89538.5 (20.4)38.2 (19.4)
 3 months17.8 (15.2)21.2 (18.7)0.44729.5 (27.8)26.5 (26.4)0.93525.6 (24.8)23.1 (22.0)
 12 months12.1 (17.0)16.0 (19.1)0.38819.7 (25.1)20.5 (26.9)0.44517.2 (22.8)17.6 (22.2)
Worst or activity-related pain (VAS/100)
 Baseline58.6 (14.3)60.8 (16.1)0.55563.0 (19.6)60.8 (23.2)0.59761.5 (18.0)60.8 (18.9)
 3 months32.3 (23.7)30.1 (23.2)0.69642.3 (29.6)40.4 (29.5)0.96940.9 (28.3)33.9 (26.1)
 12 months23.7 (25.2)23.7 (24.1)0.99330.5 (30.1)30.6 (32.5)0.21528.2 (28.5)26.1 (27.4)
AKPS (/100)
 Baseline75.2 (8.67)71.0 (9.87)0.07565.8 (13.2)64.9 (15.1)0.30968.9 (12.6)68.8 (12.4)
 3 months84.3 (10.7)83.5 (10.7)0.78475.2 (16.6)77.8 (16.7)0.78278.3 (15.4)81.5 (13.6)
 12 months86.7 (9.27)88.0 (10.9)0.61180.9 (18.0)81.8 (15.4)0.32882.9 (15.7)85.6 (13.1)
FIQ (/16)
 Baseline10.6 (1.64)9.70 (2.14)0.0359.20 (2.38)9.60 (2.60)0.3989.67 (2.25)9.67 (2.31)
 3 months13.7 (2.11)12.8 (2.64)0.15111.9 (3.38)12.0 (3.37)0.83512.5 (3.09)12.5 (2.93)
 12 months13.7 (2.39)13.6 (2.82)0.85912.8 (3.12)13.2 (3.36)0.66513.1 (2.90)13.4 (3.00)
Treatment0.4910.662
 Usual careNANA19 (47.5%)47 (51.6%)19 (31.7%)47 (18.8%)
 Supervised exercise therapyNANA21 (52.5%)44 (48.4%)21 (35.0%)44 (17.6%)
 Physiotherapy4 (20.0%)41 (25.8%)NANA4 (6.70%)41 (16.4%)
 Foot orthoses8 (40.0%)38 (23.8%)NANA8 (13.3%)38 (15.2%)
 Flat inserts4 (20.0%)40 (25.2%)NANA4 (6.70%)40 (16.0%)
 Physiotherapy+foot orthoses4 (20.0%)40 (25.2%)NANA4 (6.70%)40 (16.0%)
  • *Variables measured at baseline unless otherwise stated.

  • AKPS, Anterior Knee Pain Scale; BMI, body mass index; FIQ, Functional Index Questionnaire; NA, not applicant; VAS, visual analogue scale.