PROOF validation


Patient reported outcome measures (PROMs) are widely used to evaluate patients’ satisfaction after treatment. Very few of these questionnaires are available for children. The patient reported outcome of fractures (PROOF) is a recently developed and validated questionnaire that is used to evaluate both the children’s and parent’s satisfaction after treatment of a fracture. In the Netherlands, there is no validated PROM available for children with fractures.



The aim of the study is to translate and validate the PROOF questionnaire into Dutch.   



The PROOF is a multi-center study based on a questionnaire intended to evaluate children’s and parent’s satisfaction after treatment of a fracture. The PROOF questionnaire consists of several versions, based on group (upper extremity, lower extremity), age (child, parent) and extensiveness (short version, long version).  The questionnaires consist of 4 subscales: an aesthetic part/’how it looks’, a sensory part/’how if feels’, a functional part/’how it works’, and a rehabilitation part/’how it healed’. A question on satisfaction is added following the subscale questions. Patients score each question on a Likert scale in comparison to the opposite uninjured extremity. The Likert scales differ in subscales, ranging from 0-2 to 0-5. The total scores are transformed into a scale of 0-100. Higher scores indicate better results after treatment and higher satisfaction. 

Forward and backward translation of the PROOF questionnaire have been executed following official guidelines. The last step of the translation process consisted of pretesting the version on 20 random patients and parents (10 upper extremity, 10 lower extremity). Following pretesting feedback, the final version is used in the validation process. 

The validation process is performed according to COSMIN guidelines. Data are collected from patients receiving treatment at participating centers. Patients are divided into two groups; an upper extremity fracture group, and a lower extremity fracture group. Both groups will include a random 150 patients aged between 5 and 17 years, who are treated for any fracture (no discriminations). After written informed consent is achieved, a first package of PROM questionnaires is administered in the early period after the fracture (i.e., between 1 and 6 weeks). In this stadium, data on patient characteristics are obtained; sex, age, email address, type of fracture, fracture side and type of treatment (operative or nonoperative). The second package of PROM questionnaires is administered 6 months after the fracture. The questionnaires is completed digitally (in Castor online or locally on iPad tablets), and the risk of missing data or incorrect data is minimized. The package of PROM questionnaires contains the following instruments: the Dutch version of the PROOF questionnaire (in which the long version and short version is combined), numeric rating scale (NRS) pain and Oucher score (depending on age), the Pediatric Outcome Data Collection Instrument (PODCI) and the EQ-5D-Y. The upper extremity group also includes the shortened version of the Disability of Arm, Shoulder and Hand (QuickDASH) questionnaire. The lower extremity group includes a modified version of the Oxford Ankle Foot Questionnaire for Children (OxAFQ-C). Minor modifications were made to the original questions of the OxAFQ-C in order to contain all lower extremity fractures, instead of focusing only on ankle and foot fractures. At 6 months + two-week interval the PROOF is re-administered to analyze test-retest reliability. To minimize inconsistencies, an additional question is implemented in the re-administered PROOF questionnaire to check whether any change in symptoms have occurred during the two-week interval.