The Whitaker Classification of Craniosynostosis Outcomes: An Assessment of Interrater Reliability

The Whitaker classification is a simple and widely used system for describing aesthetic outcomes after craniosynostosis surgery. The purpose of this study is to evaluate its interrater reliability for patients who have undergone fronto-orbital surgery.

A retrospective review of patients with craniosynostosis who underwent surgical intervention at a tertiary referral center was conducted. Inclusion criteria were as follows: single-suture craniosynostosis, surgical intervention before age 2 years, and photographs taken before revisions between 5 and 20 years of age. Thirteen craniofacial surgeons independently reviewed the subjects' photographs and assigned Whitaker classifications. Interrater reliability was assessed with the Cohen kappa statistic.

Twenty-nine subjects were included. Average ages at surgery and at the time of postoperative photography were 0.8 year and 12.8 years, respectively. The κ value for all 13 raters was 0.1567 (p < 0.0001), indicating "slight agreement." Pairwise comparisons demonstrated κ values ranging from 0.0384 to 0.5492. The average rating for the set of 29 photographs differed significantly across the 13 raters (p = 0.0020) and ranged from 1.79 ± 0.68 to 2.79 ± 0.77. Finally, we found that average Whitaker classification did not differ significantly between subjects who subsequently underwent cranioplasty and/or fronto-orbital advancement and those who did not (subsequent procedures, 2.45 ± 0.55; no subsequent procedures, 1.88 ± 0.78; p = 0.1087).

The Whitaker classification exhibits low interrater reliability and does not predict future treatment. It may benefit craniofacial surgeons to create new evaluation tools with greater precision, to improve the quality of patient care and craniofacial outcomes research.