Introduction: The Effectiveness of external cervical orthosis depends on correct collar application. Data on correct cervical collar application is lacking. We sought to measure the level of agreement in interpretation of correct collar application between cervical fusion patients and trained observers.

Methods: We prospectively interviewed consecutive patients who underwent anterior/posterior cervical fusion in two hospitals with multiple surgeons at their 2-9 weeks’ postoperative visits from 2/1-8/1/2017. We excluded personal injuries or patients <18-year-old. Patients and trained raters both evaluated the correct application of the Vista cervical collar simultaneously using a cloud-based and secured questionnaire with a 4-point ordinal scale (Fig.1). Patients were blinded to the assessment by raters. Patient and raters evaluated the collar application once. Raters were selected randomly from departmental researchers who were trained using a standardized Vista collar training video produced by Aspen Medical Products. Patients were verbally trained by the nurses/residents on discharge. Assuming null hypothesis with an Intraclass correlation (ICC) coefficient of 0.5, we need 138 patients to detect a 2-tail disagreement of 0.2. Single-rating, absolute-agreement, two-way random-effects model was used. We accepted ICC value of <0.5 as poor agreement and p<0.05 as significant.

Results: One hundred sixty-two collar applications were evaluated by the patients themselves and 8 trained raters. There was no replicate observation. Patient characteristics were presented in table 1. There were 120 (75%, 95% CI 0.68-0.8) concordant pairs. The single measure ICC was 0.48 (95%CI, 0.35-0.59, P<0.0005).

Conclusions: Our data demonstrated poor agreement between trained observers and patients regarding correct collar application. To accurately evaluate the effect of external cervical orthosis on cervical fusion, the collar needs to be applied correctly. Standardized orthosis application training is recommended.

Patient Care: Understanding that standardized training method using video will give patients a better understanding of correction collar application which will, in turn, improve the effectiveness of cervical collar on cervical fusion.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the interobserver agreement on correct use of external cervical orthosis

References: Kottner J, Audigé L, Brorson S, Donner A, Gajewski BJ, Hróbjartsson A, Roberts C, Shoukri M, Streiner DL. Guidelines for Reporting Reliability and Agreement Studies (GRRAS) were proposed. J Clin Epidemiol. 2011 Jan;64(1):96-106. PubMed PMID: 21130355. Koo TK, Li MY. A Guideline of Selecting and Reporting Intraclass Correlation Coefficients for Reliability Research. Journal of Chiropractic Medicine. 2016;15(2):155-163. Computing Intraclass Correlations (ICC) as Estimates of Interrater Reliability in SPSS. http://neoacademic.com/2011/11/16/computing-intraclass-correlations-icc-as-estimates-of-interrater-reliability-in-spss/ Intraclass correlation coefficient. https://www.medcalc.org/manual/intraclasscorrelation.php Vista collar demonstration video. https://youtu.be/jgxv4L9CZbg