The International Knee Documentation Committee Subjective Knee Evaluation Form: normative data

BACKGROUND: The International Knee Documentation Committee Subjective Knee Evaluation Form may be used to measure symptoms, function, and sports activity for people with a variety of knee disorders, including ligamentous and meniscal injuries, osteoarthritis, and patellofemoral dysfunction. To date, normative data have not been established for this valid, reliable, and responsive outcomes instrument. PURPOSE: To provide clinicians and researchers with normative data to facilitate the interpretation of results on the International Knee Documentation Committee Subjective Knee Evaluation Form. STUDY DESIGN: Cross-sectional survey. METHODS: The Subjective Knee Evaluation Form was mailed to 600 people in each of 8 age/gender categories (18-24 years, 25-34 years, 35-50 years, and 51-65 years for both male subjects and female subjects). Participants were drawn from a panel of 550 000 households (1 300 000 subjects) representative of noninstitutionalized persons in the United States and were matched to data from the United States Census Bureau on geographical region, market size, income, and household size. RESULTS: Complete data were available for 5246 knees. Twenty-eight percent of respondents reported an injury, weakness, or other problem with one or both knees. Normative data were determined for respondents as a whole and for the subset of respondents with no history of knee problems. Mean scores were determined for men aged 18 to 24 years (89 +/- 18), 25 to 34 years (89 +/- 16), 35 to 50 years (85 +/- 19), and 51 to 55 years (77 +/- 23); mean scores were also determined for women aged 18 to 24 years (86 +/- 19), 25 to 34 years (86 +/- 19), 35 to 50 years (80 +/- 23), and 51 to 65 years (71 +/- 26). Scores were higher for the subset of respondents with no history of current or prior knee problems. CONCLUSION: Scores on the International Knee Documentation Committee Subjective Knee Evaluation Form vary by age, gender, and history of knee problems. The normative data collected in this article will allow clinicians to interpret how patients with knee injuries are functioning relative to their age- and gender-matched peers and will enable researchers to determine the clinical outcomes of treatment.