Table 4

Univariable and multivariable association between baseline characteristics and persistent knee symptoms at 1-year follow-up of the patients receiving a GP diagnosis of patellofemoral pain syndrome

VariableUnivariate 1 year (n=74)Multivariate 1 year (n=74)
Pooled
OR (95% CI)
Pooled
Sig
Pooled
OR (95% CI)
Pooled
Sig
AUC
Patient characteristics0.70
 Age in years1.0 (0.9 to 1.1)0.98
 Gender (men vs women)1.2 (0.5 to 3.3)0.69
 Body mass index >252.3 (0.7 to 7.7)0.19*
 Low/middle education level2.4 (0.8 to 6.8)0.11*2.5 (0.8 to 7.8)0.12
 Comorbidity skeletal system0.8 (0.3 to 2.5)0.75
 Non-skeletal comorbidity3.5 (0.7 to 17.9)0.13*3.4 (0.6 to 19.7)0.17
 Poor health (COOP-WONCA)2.7 (0.7 to 11.0)0.17*3.7 (0.9 to 15.5)0.09
 Sports0.4 (.01 to 1.5)0.18*
Symptom characteristics0.70
 Duration >3 months1.0 (0.4 to 2.8)0.95
 Recurrent symptoms0.6 (0.2 to 1.7)0.35
 Bilateral symptoms2.0 (0.7 to 5.6)0.18*2.6 (0.9 to 8.1)0.09
 Pain (11-point scale)1.0 (0.8 to 1.2)0.88
 Self-report warm knee1.3 (0.4 to 4.1)0.63
 Self-report swollen knee2.6 (0.8 to 8.4)0.12*2.5 (0.7 to 9.2)0.17
 Self-report crepitus knee1.0 (0.1 to 6.2)0.95
 Locking of the knee (Lysholm)4.2 (0.9 to 20.3)0.07*3.9 (0.7 to 20.1)0.11
 Instability of the knee (Lysholm)1.2 (0.4 to 3.2)0.78
 History of knee symptoms1.9 (0.7 to 5.4)0.23
 WOMAC function1.0 (0.9 to 1.0)0.21
 WOMAC pain1.0 (0.9 to 1.0)0.24
 WOMAC stiffness1.0 (0.9 to 1.0)0.31
Patient and symptom characteristics0.76
 Low/middle education level4.5 (1.2 to 16.4)0.02
 Poor health (COOP-WONCA)4.7 (0.9 to 23.8)0.06
 Bilateral symptoms3.4 (1.0 to 11.8)0.05
 Self-report swollen knee4.9 (1.2 to 20.2)0.03
  • *Selected in ≥3 out 5 imputed databases (p≤0.20).

  • AUC, area under the receiver operating curve; COOP, primary care cooperative information project; GP, general practitioner; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index; WONCA, world organization of family doctors.