The Pediatric International Knee Documentation Committee (Pedi-IKDC) Subjective Knee Evaluation Form: Normative Data

Abstract

Objectives: To aid in the interpretation of Pedi-IKDC scores by characterizing normative data in children and adolescents. Also, to validate the Pedi-IKDC by examining differences in Pedi-IKDC scores between patients with knee ailments compared to patients without a history of knee problems. Methods: Cross-sectional survey of 2000 children and adolescents aged 10-18 years living in the United States, recruited by ORC International to obtain equal numbers by sex and by integer age group. In addition to completing the Pedi-IKDC for one study-designated "index" knee (right or left), subjects were asked demographic questions and for information on history of knee surgery and recent (four weeks) activity limitations. Raw Pedi-IKDC total scores were re-scaled to a 0-100 scale. Non-parametric Wilcoxon or Kruskal-Wallis tests were used to compare subgroup scores and the van Elteren test was used to adjust for age. Unadjusted and adjusted p-values were similar and only unadjusted values are reported. Results: Numbers of respondents are uniform with respect to age and sex, with 11% in each age group (10-18) and 50% female. 68% identified themselves as white, and 86% as non-Hispanic. 49 states and DC are represented. 136 (7%) reported prior surgery in one or both knees; 79(4%) in the index knee. The Pedi-IKDC score distribution is skewed left with mean score (±SD) of 86.7(±16.8), median 94.6 and 34% reaching the ceiling value of 100. Subjects reporting prior surgery or limited activity in the index knee had median Pedi-IKDC scores about 25 points lower than those without these histories (p<0.0001 for both comparisons). In contrast, although statistically significant, the variation by age (p=0.02), race (p=0.02), ethnicity (p=0.01), and level of sports/exercise participation (p=0.04) was much smaller (all ranges of median scores <4.5). There were no significant differences by sex or geographic region. Conclusion: There is only minor variation in Pedi-IKDC scores across demographic factors. The strong association between Pedi-IKDC score and prior knee surgery and also with recent limitation of activity in the index knee supports the construct validity of the Pedi-IKDC. Using a large, broadly representative sample, this study supports the use of the Pedi-IKDC as a knee specific outcome instrument for pediatric patients aged 10-18 and provides normative values to aid the interpretation of scores in this age range.

Focal Periphyseal Edema: Are We Overtreating Physiologic Adolescent Knee Pain?

“…Patients who met the study criteria were contacted by telephone to obtain consent for participation and to administer two clinical outcome instruments, the Short Form 10 (SF-10) and the Pediatric International Knee Documentation Committee (pedi-IKDC). 3 Results of the SF-10 were analyzed using Quality Metric scoring software provided by OptumInsight; results of the pedi-IKDC were analyzed using Microsoft Excel software.…”

Treatment Decision after Anterior Cruciate Ligament Injury, and Evaluation of Measurement Properties of a Patient Reported Outcome Measure

“…One study 32 showed a 30% ceiling effect, by using a population of patients that had undergone ACLR 2-4 years ago, where such high scores can be expected. A 34% ceiling effect was found in another study, where children with "previous knee disorders" filled out the questionnaire 91 . Since there was no further description of what the knee disorder was, it is difficult to evaluate the importance of that result.…”

“…There was new evidence for hypothesis testing, translation validity and criterion validity (table 2). Interpretability in terms of floor and ceiling effects was consistently low, except in two studies 32, 91 , in a population that had undergone ACLR 2-4 years ago and a population of "children with a history of knee surgery". Muller et al 90 defined the threshold for patient acceptable symptoms score as 75.9 points.…”

“…There were 14 additional full text articles for evaluation (figure 3), and 4 articles that evaluated interpretability only 90,91,104,107 (appendix 1).…”

Editorial Commentary: We PROMIS…One More Patient-Reported Outcome Questionnaire!

“…Third, we need to understand how to apply the pediatric PROMIS domains to our pediatric and adolescent patients, especially in sports medicine that has very few age-appropriate PROMs despite experiencing a large increase in the incidence of youth sports injuries and treatment methods. [17][18][19][20][21][22] Finally, we need to work with our institutions and specialty societies to guide the conversation around how these data will be used by the government and thirdparty payers. As PROMs such as PROMIS become linked to reimbursement, we as a profession want a seat at the table as these policies are being created.…”