Reliability of the Dutch translation of the Kujala Patellofemoral Score Questionnaire

Objective. There are no Dutch language disease-specific questionnaires for patients with patellofemoral pain syndrome available that could help Dutch physiotherapists to assess and monitor these symptoms and functional limitations. The aim of this study was to translate the original disease-specific Kujala Patellofemoral Score into Dutch and evaluate its reliability. Methods. The questionnaire was translated from English into Dutch in accordance with internationally recommended guidelines. Reliability was determined in 50 stable subjects with an interval of 1 week. The patient inclusion criteria were age between 14 and 60 years; knowledge of the Dutch language; and the presence of at least three of the following symptoms: pain while taking the stairs, pain when squatting, pain when running, pain when cycling, pain when sitting with knees flexed for a prolonged period, grinding of the patella and a positive clinical patella test. The internal consistency, test-retest reliability, measurement error and limits of agreement were calculated. Results. Internal consistency was 0.78 for the first assessment and 0.80 for the second assessment. The intraclass correlation coefficient (ICCagreement) between the first and second assessments was 0.98. The mean difference between the first and second measurements was 0.64, and standard deviation was 5.51. The standard error measurement was 3.9, and the smallest detectable change was 11. The Bland and Altman plot shows that the limits of agreement are -10.37 and 11.65. Conclusions. The results of the present study indicated that the test-retest reliability translated Dutch version of the Kujala Patellofemoral Score questionnaire is equivalent of the test-retest original English language version and has good internal consistency. Trial registration NTR (TC = 3258). Copyright (C) 2015 John Wiley & Sons, Ltd.