Validity and internal consistency of the international knee documentation committee subjective knee evaluation form in children and adolescents.
BACKGROUND
The International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form (IKDC Knee Form) is a valid, reliable, and responsive measure of knee-related symptoms, function, and sports activities in adults. Despite the incidence of knee injuries in younger individuals, the measurement characteristics of the IKDC Knee Form have not been established. Hypothesis/


OBJECTIVE
The purpose of this study was to investigate the validity and internal consistency of the IKDC Knee Form in pediatric, adolescent, and young adult patients with a variety of knee conditions. The authors hypothesized that the IKDC Knee Form would be a valid and consistent measure of knee function in these age groups.


METHODS
Cohort study (diagnosis); Level of evidence, 2.


METHODS
The IKDC Knee Form and Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL) physical functioning component were administered to 673 individuals between 6 and 18 years of age. The internal consistency and validity of the IKDC Knee Form were determined for the entire cohort and for age group cohorts (pediatric, 6-12 years; adolescent, 13-15 years; young adult, 16-18 years) using the PedsQL physical functioning component for comparison.


RESULTS
The results were similar across all age groups. In the original format, internal consistency was high and factor analysis showed a single, dominant component underlying the item responses for each age group. Items 2, 3, and 6 may contribute to measurement error in young individuals. Correlation between the IKDC Knee Form and PedsQL physical functioning component score was moderately high for the entire cohort (r = .83) and for all age groups (pediatric, r = .84; adolescent, r = .84; young adult, r = .79).


CONCLUSIONS
In its current form, the IKDC Knee Form is a valid and consistent knee-specific measure of symptoms, function, and sports activity in individuals between the ages of 6 and 18 years with a variety of knee problems. Further work is needed to establish the reliability and responsiveness of the IKDC Knee Form for this age group.
Schmitt
Laura C
LC
Cincinnati Children’s Hospital Medical Center, Ohio 45229, USA. laura.schmitt@cchmc.org
Paterno
Mark V
MV
Huang
Samuel
S
D000293:Adolescent; D000367:Age Factors; D018771:Arthralgia / Q000175:diagnosis / Q000473:pathology; D001265:Athletic Injuries / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology; D002648:Child; D015331:Cohort Studies; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D015994:Incidence; D015601:Injury Severity Score; D007718:Knee Injuries / Q000175:diagnosis* / Q000473:pathology / Q000523:psychology; D007719:Knee Joint / Q000473:pathology*; D008297:Male; D010147:Pain Measurement; D011594:Psychometrics; D011788:Quality of Life / Q000523:psychology; D015203:Reproducibility of Results; D013223:Statistics as Topic; D011795:Surveys and Questionnaires / Q000592:standards*