Field-test and Psychometric Validation of the Pectus Excavatum Evaluation Questionnaire in the Dutch Pectus Excavatum Population

A questionnaire that can measure disease severity from the patients perspective in patients with pectus excavatum already exists in English (Pectus Excavatum Evaluation Questionnaire; PEEQ). This questionnaire was recently translated into Dutch. Before this Dutch version can be used, it needs to be tested by a number of patients. Data will be collected at three moments: 1. Preoperatively: The PEEQ will be completed on paper during the outpatient clinic visit. 2. Postoperatively: The PEEQ will be completed electronically 2 months post-surgery. 3. Test-retest reliability: The PEEQ will be administered electronically at least two weeks after a previous assessment.