Analysis of patient-reported anterior knee pain scale: implications for scale development in children and adolescents

Abstract

Purpose 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 patel-lofemoral pain diagnosis were comparable: r [498] = 0.70 (R2 = 0.49, short form) and r [498] = 0.71 (R2 = 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). Conclusion 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.

Patellofemoral Pain

“…302 The minimal clinically important difference (MCID) for the AKPS is 8 to 10 points. 70 I Myer et al 202 developed a 6-item short form of the AKPS in 499 girl and adolescent female athletes. The internal consistency of the 13-item form had a Cronbach alpha of .92 and a standard error of measurement (SEM) across all items of 0.003.…”

Reliability and Validity of the Anterior Knee Pain Scale: Applications for Use as an Epidemiologic Screener

“…The study was designed to assess patellofemoral pain in a diverse, non-clinical sample of adolescent female athletes who participated in three interscholastic sports programs, namely basketball, soccer, and volleyball, within a single school district in rural Kentucky (3.9% African American, 94.0% European American (White), 1.0% Asian and 1.2% Hispanic). See Myer et al [ 7 ] for a more complete description of the sample and methods used to obtain the primary data. Signed written informed consent was obtained from the parent/guardian of all participants under the age of 18.…”

“…Traditional test-retest reliability analyses were not deemed appropriate given the changing nature of the samples with respect to injuries, the length and complexity of seasons with respect to additional sports and activities, as well as the restricted nature of the scores for segments of the sample (e.g., ceiling effect of healthy scores). Throughout all analyses described here, the original 13-item (long) form of the AKPS was evaluated as well as the 6-item short form identified by Myer et al [ 7 ] in both the ordinal and dichotomized scoring formats. All analyses were descriptive in nature, used a pre-specified statistical analysis plan approved by the entire team, and computed using SAS v9.3 software.…”

Validity and Reliability of the Indonesian Version of the Kujala Score for Patients With Patellofemoral Pain Syndrome

“…9 The sensitivity of this tool is 80%, and the specificity is 90%. 12 The other diagnostic tool recently used to diagnose PFPS is the Survey Instrument for Natural History, Etiology, and Prevalence of Patellofemoral Pain Studies (SNAPPS) questionnaire. The SNAPPS questionnaire has also shown high sensitivity and specificity (>90%).…”