The Development of a Core Outcome Set for Adolescents Undergoing Spinal Deformity Surgery: An AOSpine Knowledge Forum Deformity Initiative
Authors: Haanstra Tsjitske , van Hooff Miranda , Germscheid Niccole , de Kleuver Marinus 
Published: April 2016

Introduction Routine patient-related outcome monitoring is gaining importance in medical care. Health care providers are putting more emphasis into assessing the value (health gain per unit cost) of treatment provided. Outcome registries including patient-reported outcome (PROMs) data such as patient satisfaction, patient expectations, and health-related quality of life, can provide evidence and insight into the quality of care within and between care facilities and in comparing different treatment strategies. In particular for spinal deformity surgery where randomized controlled trials (RCTs) are unethical and not practical, and there is tremendous variability in management strategies, outcome monitoring by the means of outcome registries would be of value. Outcome registries are most valuable if they are comparable between countries and include outcomes that are relevant to the patient population of interest. Therefore, it is of utmost importance to internationally agree upon the most important outcomes and candidate predictors of outcomes to measure. The COSSCO1 (Core Outcome Set for SCOliosis) project aims to reach consensus across the Nordic Spinal Deformities Society (NSDS; Sweden, Denmark, Finland, Norway, and the Netherlands) about which patient relevant outcome domains are to be included in outcome registries for adolescents (10–25 years) undergoing spinal deformity surgery (e.g., adolescent idiopathic scoliosis, Scheuermann kyphosis), from both the patients' and clinicians' perspective. Material and Methods A spinal deformity surgeon representative from each of the NSDS registries was invited to participate in a modified Delphi study with three consensus rounds. Using the World Health Organization's International Classification of Functioning, Disability and Health (ICF) framework, a list of 39 potential core domains was drafted based on a systematic review of the literature and presented to the Delphi participants who were asked to vote which domains were essential. A threshold of 70% consensus was used. The first consensus round was held face-to-face during the NSDS-meeting in August 2015. The second and third consensus rounds will be completed through web-based surveys before the end of 2015. In each round suggestions about overlap, aggregation, or additional core domains are used as input for subsequent rounds. After consensus is reached about which domains are “core,” further consensus rounds will be initiated on the appropriate measurement instruments to measure the core outcome domains and on the factors that contribute to these core outcomes (predictive factors). Results COSSCO1 will be completed in February 2016. These results will then be validated among patients (and their parents) and translated into a uniform outcome instrument that will be implemented in the five Nordic national spine registries. Conclusion The development of this outcome set will facilitate comparisons across studies, registries, and nations to improve the quality of daily clinical practice in adolescents undergoing spinal deformity surgery. Acknowledgments We would like to thank the representatives of each NSDS countries for their participation in the COSSCO1 project, the AOSpine deformity knowledge forum for their financial and administrative support, prof. dr. David Polly for moderating the consensus meeting and Roderick Holewijn and Sayf Faraj for their administrative support.