Analysis of patient-reported anterior knee pain scale: implications for scale development in children and adolescents.
OBJECTIVE
The purpose of this investigation was to estimate and document the reliability and validity of the Anterior Knee Pain Scale (AKPS) and to estimate its relative prediction accuracy of anterior knee pain in young females.


METHODS
Data from a prospective, epidemiologic study to diagnose patellofemoral knee pain among female athletes (n = 499) using the Anterior Knee Pain Scale (AKPS). Data were treated in 4 phases (descriptive phase, reliability phase, scale refinement phase) and a final validation stage that was focused on an effort to test and document the validation of the AKPS short form and perform head-to-head comparisons of the 6-item short form with the original, 13-item form.


RESULTS
The AKPS was reduced from 13 items (αCoeff = 0.77, σSEM = 0.004) to 6 items (αCoeff = 0.78, σSEM = 0.004). Point-biserial correlations with patellofemoral pain diagnosis were comparable: r [498] = 0.70 (R(2) = 0.49, short form) and r [498] = 0.71 (R(2) = 0.51, long form), as was sensitivity: 84% (short form) and 80% (long form), and specificity: 89% (short form) and 90% (long form; AUC = 0.94 both).


CONCLUSIONS
The current analyses indicate that a subset of measures from the AKPS is responsive to patellofemoral pain symptoms and may support screening for related diagnoses. A simpler and quicker scale optimized for diagnostic accuracy could reduce the demand on patients, clinicians and research teams focused on the identification and management of patellofemoral pain.


METHODS
III.
Division of Sports Medicine, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue; MLC 10001, Cincinnati, OH, 45229, USA. greg.myer@cchmc.org.|Department of Pediatrics and Orthopaedic Surgery, University of Cincinnati, Cincinnati, OH, USA. greg.myer@cchmc.org.|Sports Medicine Sports Health and Performance Institute, The Ohio State University, Columbus, OH, USA. greg.myer@cchmc.org.|Micheli Center for Sports Injury Prevention, Boston, MA, USA. greg.myer@cchmc.org.
Gregory D
GD
Myer
Division of Sports Medicine, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue; MLC 10001, Cincinnati, OH, 45229, USA.|Division of Health Sciences, Department of Athletic Training, College of Mount St. Joseph, Cincinnati, OH, USA.
Kim D
KD
Barber Foss
Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
Resmi
R
Gupta
Division of Sports Medicine, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue; MLC 10001, Cincinnati, OH, 45229, USA.|Department of Pediatrics and Orthopaedic Surgery, University of Cincinnati, Cincinnati, OH, USA.|Sports Medicine Sports Health and Performance Institute, The Ohio State University, Columbus, OH, USA.|Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA.|Department Orthopaedic Surgery, The Ohio State University, Columbus, OH, USA.|Department Biomedical Engineering, The Ohio State University, Columbus, OH, USA.
Timothy E
TE
Hewett
Division of Biostatistics and Epidemiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
Richard F
RF
Ittenbach
D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D010147:Pain Measurement; D046788:Patellofemoral Pain Syndrome / Q000175:diagnosis*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
Anterior knee pain; Knee injury; Patellofemoral pain syndrome; Patient-reported outcomes; Scale development