The assessment of bulging fontanel and splitting of sutures in premature infants: an interrater reliability study by the Hydrocephalus Clinical Research Network.

Object: Previous studies from the Hydrocephalus Clinical Research Network (HCRN) have shown a great degree of variation in surgical decision making for infants with posthemorrhagic hydrocephalus, such as when to temporize, when to shunt, or when to convert. Since much of this clinical decision making is dictated by clinical signs of increased intracranial pressure (including bulging fontanel and splitting of sutures), the authors investigated whether there was variability in how these signs were being assessed by neurosurgeons. They wanted to answer the following question: is there acceptable interrater reliability in the neurosurgical assessment of bulging fontanel and split sutures?

Methods: Explicit written definitions of "bulging fontanel" and "split sutures" were agreed upon with consensus across the HCRN. At 5 HCRN centers, pairs of neurosurgeons independently assessed premature infants in the first 3 months of life for the presence of a split suture and/or bulging fontanel, according to the a priori definitions. Interrater reliability was then calculated between pairs of observers using the Cohen simple kappa coefficient. Institutional board review approval was obtained at each center and at the University of Utah Data Coordinating Center.

Results: A total of 38 infants were assessed by 13 different raters (10 faculty, 2 fellows, and 1 resident). The kappa for bulging fontanel was 0.65 (95% CI 0.41-0.90), and the kappa for split sutures was 0.84 (95% CI 0.66-1.0). No complications from the study were encountered.

Conclusions: The authors have found a high degree of interrater reliability among neurosurgeons in their assessment of bulging fontanel and split sutures. While decision making may vary, the clinical assessment of this cohort appears to be consistent among these physicians, which is crucial for prospective studies moving forward.